Xamarin Challenge


If you’re working the Xamarin Challenge and run into any obstacles, post to this thread and the authors of the challenge will help out.

Comments (313)

313 responses to “Xamarin Challenge”

  1. George Coll

    Thanks for launching this forum post. Great challenge and it has been super working with together with your team!

  2. obideleon

    Hi, I just want to ask you why I am not getting the Step 2? Earlier today it was just like 44minutes left but after going home from school it's now "0days -4hours -46minutes -36seconds" as in it's now Negative. Why was that?

    Click here for the screenshot of I think was error.

  3. Tina


    Hi All,

    We have heard from a few of you that you have not been receiving emails for the Xamarin Challenge. What we have discovered is that you may have actually unsubscribed from receiving marketing emails from our company. Since we need to comply to the law and not send emails to those of you who have unsubscribed, there is a way around this:

    You can go to any of the Steps in the challenge at these URL's




    Once there, you will receive a form that asks for your challenge email and key phrase. The key phrase is the Challenge Reminder phrase that you gave when you registered. Once you submit these two pieces of information, then you will be given access to the correct step you are in -- in your process.

    If you try to use this method to access the wrong step in the process, the screens will communicate that you need to access the correct step and lead you to that step where you will once again have to verify with your email address and key phrase.

    If you continue to have a problem, please feel free to email me at [email protected]

    Hope this helps a few of you out there.


    P.S. If you do know your challenge code, then you can use the following url pattern to access any of the steps:

    https://xamarinchallenge.thurrott.com/step-1/[EMAIL]/[CHALLENGE CODE]

    https://xamarinchallenge.thurrott.com/step-2/[EMAIL]/[CHALLENGE CODE]

    https://xamarinchallenge.thurrott.com/step-3/[EMAIL]/[CHALLENGE CODE]

    Once again, if you try to access a step you are not authorized to access, you will be given on screen instructions to go to the correct step.

    • hm-thurrott.com

      In reply to Tina: Quote: "...What we have discovered is that you may have actually unsubscribed from receiving marketing emails from our company..."

      Is there any URL/email subject line one could use to opt-in after the fact?

      <please ignore, see update below instead> Update: 2017-04-25: Probably too late for this at this point but a suggestion: You currently block the steps that are not yet available to the challengers; how about (if only for next time?) you mark the completed steps in some similar fashion (but just allow the page viewer to continue on to that page. E.g. </please ignore, see update below instead>

      Update: 2017-04-26: Just encountered for the first time my 72-hr count down on my next step (-3); which effectively i) confirms completion of previous step as well ii) letting me know when my 72-hrs are up to the second!

      Update: 2017-04-28 06:49: Waiting on my 72-hr embargo to finish up my last step. I have been relying on the count-down-counter for the next step as verification that the current step is completed - but no next step for the final step. Is there an indirect way to verify (with no emails coming in) that step 3 is completed. Say a "Hall/Page of Fame" where we can look up our ID/Code/? to see if we are accounted for?

      Update: 2017-04-28: Just reviewed my registration; there is nothing about opting out of marketing material as part of the registration process; thinking that this is not the reason that I'm not getting my emails.

    • timmiller

      In reply to Tina:

      Hi Tina,

      Thanks for this. I was able to complete Step 1 and get it running on a Windows emulator. I could not seem to get the Android emulator working. But have added all the appropriate code and files. Will I be allowed to advance to Step 2?


    • Tim

      In reply to James Toalu:

      Go ahead and try again. Your completion date was early this morning and before we ran our updates.

      I just tested the URL with your credentials and it's working

    • jmeiii75

      In reply to James Toalu:

      I'm having the exact same issue when trying to access Part 3 after completing Part 2

  4. Payton

    In reply to Payton:

    A bit more information: When I reload the application on a new system, clean install, the first (killer) error I get is in the CoolBreeze.Android project, "The referenced component 'System.ObjectModel' could not be found.

  5. littlejohnjt

    I got a late start on the challenge and was able to complete part 1 pretty quickly but was only able to run the UWP locally. I cannot seem to get either the Windows mobile emulator or Android emulators to run successfully. I can't deploy to the Window Mobile emulator, it returns an error indicating the emulator failed to start. As for the Android emulator, it launches, but the emulator does not have a connection to the network, so the application encounters an exception.

    I have attempted, via Hyper-V to set the Andriod VM to an external network, but then the VM/Emulator fails to launch completely. As for the Windows Mobile emulator, not exactly sure, I need to Bing/Google the exact error.

    Development platform: Surface Pro 3, build 16170, 8GB RAM, VS 2017 Enterprise

    Any help is much appreciated!

    • Todd
    • jt5

      In reply to littlejohnjt:
      I had a similar issue with the Android emulator. I fixed it by adding a second virtual adapter in the hyper-v tied to my wireless adapter on my sp3 and setup as an external network. I kept the first adapter as an internal network.  I then added the second connection to each Android vm in the hyper-v manager. I made sure the wireless was connected. Then the emulator would connect to the web- and everything worked.

      • littlejohnjt

        Thanks for the help! I swear I tried this early on with no luck. I updated the VM with an external network interface and it worked. I believe I tried this early on and the VM simply wouldnt start. Thanks again!In reply to jt5:

  6. RonH

    I am still waiting to get the email to start the second part... about 10 days now..

    Is this were I should post, or is there somewhere else?

  7. jmeiii75

    Alright! Finished Part 2 and was able to get everything working on Android Emulator, the Windows Phone Emulator, and the UWP app running on the local machine. Looking forward to completing Part 3, and the challenge as a whole. Hopefully, I get my email soon.

  8. leonzandman

    I've finished part 2, but haven't yet received part 3...

  9. Bigwillt

    So I had some issues with part 2 and I had some VS2017 updates available and I thought, "Maybe I need to update?"

    Now I have completely borked my project. The UWP will run but the Android will not.

    Is there any way to start at Part 2 without having to restart at Part 1?

    • siko

      In reply to Bigwillt:

      Tried a 'Clean solution'?


      If you updated windows or a windows sdk, check your project file ...uwp.csproj on the supported version:



  10. roman203

    Receiving Error on "cityPicker" " The 'cityPicker' does not exist in the current context" the built in solutions only seem to make the problem more pronounced. Any assistance will be greatly appreciated.

  11. YEHUDA

    After Successfully completing the first 2 parts of the challenge, and most of the 3rd part. I'm at a standstill: When I click on submit challenge in my app running in the emulator it crashes and I get a unhandled exception error. HELP????

    • jt5

      In reply to YEHUDA:

      I am having the same issue. I have tried the other fixes listed- but no luck. Anyone else with an idea? I also updated visual studio and then did a clean and deploy/build. I went through and redid the step 3 parts- but still no avail. I went through the debugger to see if I could find the line it is crashing on and it is one of these lines in SubmissionInformation.cs:

      CloudBlobContainer container = new CloudBlobContainer(new Uri(_submissionLocation));

      var blob = container.GetBlockBlobReference($"{App.RegistrationCode}.submission");

      I don't think it is getting to the blob line though. I verified registrationCode is passed in correctly. I have verified the submissionLocation is correct. I tried it in another Android emulator as well and it did not work either. Not sure what else to do here. Everything else has worked- just trying to submit my entry and get entered to win a surface studio.

      • timo47

        In reply to jt5:

        I had the same problem: the execution failed between those 2 lines. Cleaning the solution did not help. Ultimately I resolved it by reinstalling the WindowsAzure.Storage package.

    • GrizzlyStrong

      In reply to YEHUDA:

      I finally got it to work. I updated all the nu-GET packages and commented out the following App.xaml.cs

      //using Microsoft.Azure.Mobile.Analytics;

      //using Microsoft.Azure.Mobile.Crashes;

                 //MobileCenter.Start(typeof(Analytics), typeof(Crashes));

    • GrizzlyStrong

      In reply to YEHUDA:

      having the same issue. I checked the code correct and it seems to still happen.

      04-17 11:03:56.939 E/mono   ( 3543):

      04-17 11:03:56.939 E/mono   ( 3543): Unhandled Exception:

      04-17 11:03:56.939 E/mono   ( 3543): System.NotImplementedException: The method or operation is not implemented.

      04-17 11:03:56.939 E/mono-rt ( 3543): [ERROR] FATAL UNHANDLED EXCEPTION: System.NotImplementedException: The method or operation is not implemented.

      • GrizzlyStrong

        In reply to GrizzlyStrong:

        looks like there is an issue receiving the registration code:        

        private string _registrationLocation = $"http://traininglabservices.azurewebsites.net/api/weather/register?registrationCode={App.RegistrationCode}";

  12. Payton

    After much trouble at every step, I finally got the app finished and was able to submit successfully, according to the "Xamarin Challenge Gods" yesterday early afternoon. Then last night I got a notice from the Xamarin Team ([email protected]) that I should "get started and finish step 3". Is this anything I need to be concerned about or just a timing issue?

    • Tim

      In reply to Payton:

      Definitely a timing issue. The completion time-stamps are updated every morning. I can see that you completed the challenge yesterday. That email was likely triggered before the update went live this morning.

      • Payton

        In reply to Tim:

        Thanks, Tim. I actually just received the notification. (Story of my life--I can not find something until I ask my wife where it is, then find it before she can answer. Sigh.)

  13. Bigwillt

    I'm a little late to the party but, how do I submit Part 1 now that I have completed it?

    • jmeiii75

      In reply to Bigwillt:

      You do not have to submit. You will simply receive an email acknowledging completion. It may take a couple of days. It did for me. However, in fairness, I finished Part 1 on a Friday. Got my acknowledgement on Monday. Fortunately, the 72 hour waiting period started when I finished, not when I received the email.

  14. Mike Irving

    Hi There.

    I completed Step 2 about a week ago.. I have come back to it today and re-ran it all.

    How does your system verify I have finished, as I am still awaiting confirmation / instructions about Step 3?

    Please advise,


    • cat

      In reply to Mike Irving:
      I'm in the same boat... (step 2 done, not step 3 for over 72 hours) Also, no Step 2 "completed" email nor 'countdown clock' when I attempt to access the download (as mentioned further down the comments).
      UPDATE... 5hrs later... I just got an email that Step 2 is done, Step 3 is 72 hr wait now. What I did (not sure if this was why) was load the android app onto an old android phone and went outside (so the GPS could get it location)... I've had tons of issues with the android emulation, so maybe the thing to do is just not use it (or at least not depend on it to signal the API server that is tracking your challenge tag).

  15. BarryWallis

    I finished part 2 over the weekend and was eagerly awaiting part 3 when I got an unexpected e-mail this morning. It said they noticed I hadn't completed part 2 yet. What do I need to make sure I do to trigger part 3?

  16. DavidSlade

    Completed Part 1, but I cannot get the later version Android emulators to work. I am getting the message "Init: Failed to read from /dev/hw_random: No such device" when I connect in HyperV. It seems they just will not work on my system. None of the fixes suggested in Xamarin forums work.

    • robinwilson16

      In reply to DavidSlade:

      Hello David, I get the same message if I connect to the VM from Hyper-V but if I load it from inside Visual Studio by going to Tools > Visual Studio Emulator for Android... then it loads fine (also when it is booted up in the emulator, if I connect from Hyper-V it still gives the same error message). Did you try that? I did find the emulator to be pretty unreliable though.

      • DavidSlade

        In reply to robinwilson16:

        No, from Visual Studio does not work: "Could not connect to debugger". The emulator has lots of error messages such as "No such file or directory" and "Permission denied. I am going to try again to re-install.

    • techieg33k

      In reply to DavidSlade:

      I ended up using the x86 emulator for Android as the H-V on broke my network stack. I downloaded HAXM (https://software.intel.com/en-us/android/articles/intel-hardware-accelerated-execution-manager) and after reboot it worked fine.

  17. GrizzlyStrong

    I have done part 1 twice now and still have not received part 2 of this challenge, so if any one running this can give those of us stuck in this part of the challenge some advice that will be a great help. maybe there is something that we have missed. Or is there a way to submit the project that we have done.

    • robinwilson16

      In reply to GrizzlyStrong:

      Hello. One thing that worked for me was to re-visit the step 1 URL and then change the URL:

      https://xamarinchallenge.thurrott.com/step-1/[OTHER STUFF HERE]

      So replace step-1 with step-2 and this should take you to the page with the step 2 zip file. If it tells you that you cannot access it yet then you can view the page source to get the URL but I'm unsure if this will invalidate your competition entry.

      Hope it helps.

  18. tpiselli

    Just finished part 1 using Visual Studio for the Mac exclusively. Obviously I could not do the UWP portion but the rest went fairly smooth. Had to figure out the different menu items and options on the wizard screens but, I did get the iOS app running. The Android app crashes after it start so I'll have to look into that a little more. Overall I'd say the tool is nice though it's no Eclipse for Java: right Paul :-)

  19. JaseCutler

    I have done challenge 1 twice now start to finish, and still have not received challenge 2. How do I find out how to trigger challenge 2?

  20. jmeiii75

    I just successfully finished Part 1. Is there another step that I need to take? A link where I submit my code? I realize that there are others waiting as well and just don't want to miss anything. Thank you and I apologize if the question has been answered and I simply missed it.

  21. leonzandman

    I think I'm going to have to restart the Challenge (at least from part 2). I've stumbled upon just about every error this thread contains. I haven't been able to get the button to the Forecast page to show up in any emulator. Updated Xamarin Forms NuGet packages, but nothing works. Also deployment/debugging to both Android and Windows Mobile emulators often fails. I'm doing this on my Surface Pro 4, maybe that's problematic hardware (as I also had to enable the Hyper-V compatibility feature on that device).

    • robinwilson16

      In reply to leonzandman:

      I did mine on a Surface Pro 4 (with Creators Update) and the worst issue for me was the unreliability of the Android Emulator. I found that if Android could not access the internet then CoolBreeze just crashed and it took multiple attempts setting up the emulator until I got it working. Not sure if this is related to the specific hardware or just because the emulator is unreliable. I had no issues with UWP on my PC though.

    • BarretBlake

      In reply to leonzandman:

      I may end up restarting from the beginning. I completed part 2 a week ago and still have not received an email for part 3.

  22. Cronus

    I've just completed Part 2. I did have to manually delete my bin folder for the UWP app to get it to show the Forecast button along with the rest of the changes.

    I'm having an issue where my breakpoints aren't working on some files due to mismatching file versions. I've not only cleaned and rebuilt I've also deleted the entire bin folder again. For example Mainpage.xaml.cs gives me the error for breakpoints, but they work fine in LocationHelper.cs. This is for the UWP app, which is running fine, but I'm a bit concerned.

    How can I be getting this error even after manually deleting CoolBreeze.UWPbin?

  23. Alexander Rothacker

    There is a typo in the sample code for ForecastPage.xaml in part 2.

    The Label that is displaying the temperature is implemented as follows:

    <Label VerticalOptions="Center" Text="{Binding MaxTemperaturem, Converter={StaticResource CharacterLabelConverter}, ConverterParameter=°}" />

    But MaxTemperaturem doesn't exist, it should be MaxTemperature

  24. leonzandman

    So I finally got the forecast toolbar button appearing/working! It now works on every emulator and on a locally running UWP app.

    The solution: I guess I missed a step... I didn't wrap the creation of the StartPage in a new NavigationPage in App.xaml.cs. Stupid me. So App.xaml.cs has to have the following line:

               MainPage = new NavigationPage(new CoolBreeze.StartPage());

  25. cat

    I've done Xamarin projects (pre-Microsoft), so thought using VM-Ware on a Mac to run Windows and VS2017 would be the way to go... but have run into multiple issues.

    1. Ran out of Space on VM for VS2017 on VM
    2. VS2017 uses ONLY /tmp to install (aka couldn't install as /tmp was on C: , yes you can hack around it)
    3. Cannot install emulators when VS2017 is running on VMWare (I'm sure there is a hack for this too)

    After I hacked attempting the setup... I gave up an lit up an extra server in my grid then ran into Paul's issues...

    Given all this AND that I've had Xamarin running / building 2 years ago... I'd appreciate hearing about the setups (H/W and VM's) that people who've gotten through the challenge used.

    Is it Windows 10 setup, VS2017, H/W assumptions ? New Xamarin lib ? or am I getting to 'that age' where I should sit with Paul and Leo yelling about my grass, talking about when 1KB was a lot of memory.

    Can we do this via Visual Studio ONLINE ?

  26. shaunhey

    Unfortunately it looks like I am among those who is stuck at step 1 without receiving a confirmation message to start step 2. I completed step 1 on 4/3, seeing the weather on both the Android emulator and as a UWP app, so I know that the web service sending the weather info saw my registration code.

  27. robinwilson16

    For anyone not receiving the next part of the challenge, I have found that to access the other parts you can just modify the URL:

    https://xamarinchallenge.thurrott.com/step-1/[OTHER STUFF HERE]

    Change step-1 to the step you are up to and then when you get a message telling you that you cannot access it yet just view the source of the page and search for "Download" and you will see the URL to download the zip file.

    However if you follow this approach I am not sure if this would disqualify you from the challenge so use with caution! I tested it with another account and was able to access all 3 parts one after the other.


  28. robinwilson16


    I have now completed the challenge, however the option to submit my solution is greyed out in the UWP app for some reason, so pressing it does nothing and on the Android app I am able to submit my solution more than once but I notice there is no code to catch any errors from what I can tell and it just moves to the success message. Is there a way to confirm my entry has been accepted?

    I enjoyed the challenge and the only issue I had was getting the Android emulator to just boot and load correctly and also to detect the external network and it was very flaky. Even now CoolBreeze will sometimes open and I will be able to access all the screens and other times it will just exit immediately and it often exits on the forecast page saying "Unfortunately, CoollBreeze.Android has stopped." but other times it works. It seems if the external network connection isn't working it just crashes as the API calls don't work.

    Interestingly though. on the Visual Studio Mobile Centre these crashes are not detected and only the one error relating to the date format is listed (part of the exercise).

    The only way to get the Android Emulator to work was to set it up first from the tools menu then go into Hyper-V settings and add a second network adaptor to the VM which pointed to the external network. Doing anything else just resulted in the emulator sticking on the loading screen indefinitely and never booting. When it did load it seemed to sometimes only check the other internal adaptor and I had to keep deleting it and re-creating it until it eventually decided to work.



    • siko

      In reply to robinwilson16:

      The UWP app is not supported for the mobile monitoring stack... and apparently azure mobile is not supported either. Submitting only works in Android (or iOS, but I cannot confirm).

      Confirm that crashes in Android are not all registered in the mobile centre.

      The (google) android emulator and supporting tools are very, very buggy and hardly serious stuff IMHO.

      I would also like to know if my submission really made it to azure?!

      • robinwilson16

        In reply to siko:

        Hello Siko

        Thanks for the reply. It is surprising that Microsoft's development tools don't yet support UWP but I can see you are right and like you I can't test the iOS development.

        UWP was working well at least but since my PC updated on the fast ring to 16170, UWP debugging is broken now too it seems, at least for me.


  29. techieg33k

    FIXED: I had forgotten to Deploy the app again for Step 6. I was messing around and got the warning I needed to Deploy, so once done it works perfectly in the UWP app. So anyone else just remember to Deploy before trying to run it with the UWP.

    So I got to the end of Exercise 6 (Part 1 of this challenge) and when I run the UWP (Simulator or local) it launches with the splash screen as expected and still just say "Welcome to Zamarin Forms!" and I do not see any of the options to select the city or see the weather. This app displays perfectly on the Android Emulator. I can not test the iOS as I don't have a Mac.

    I've tried to just close out, Build, Rebuilt, and nothing changed. No errors showing. The only thing I am seeing under the Debug section is a bunch of "...Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled." I will note that the defaults when I setup the project for the UWP part was:

    Target Version: Windows 10 Creators Update (10.0; Build 15063) (no other choice can be picked!)

    Min Version: Windows 10 November Update (10.0; Build 10586)

    I am on Windows 10 Pro with Update 1607 installed currently.

  30. jmeiii75

    I was able to finish the challenge and successfully submit my solution today. This was a great learning experience. Thank you to the challenge designers and to all of those who have posted helpful information on this thread.

  31. Nic

    I’ve been trying to work my way through the challenge, and have spent many hours getting frustrated, and now I have reached a point where I am completely stuck.


    Aside from not being able to run an Android emulator in anything lower than Marshmallow, I’ve been able to get everything to work, up to a point.


    As soon as I perform the tasks for exercise 3, in part 2, to add toolbar navigation, everything stops functioning in Android.

    • The drop-down list selection is not honored on the “Now” tab
    • The current location async call never returns results (just stuck with the spinning wait icon, despite the fact that it worked prior to this step)


    This is the third time I have started from scratch, and I get exactly the same result each time, so at this point I do not believe that it is something I am explicitly doing wrong, based on the instructions. 


    It’s my understanding that there is a bug with the current version of Xamarin and the Windows app, so that the forecast does not show, however, I have been able to get this to work with Windows Mobile, but it does not seem as though anything other than the default location is being pulled (this may be correct, I cannot see a way to force location in that emulator). And despite hitting the forecast in that it does not appear as though this piece of the challenge is being marked complete for me.


    So, there is obviously some issue here that I am unable to resolve. Are there any pointers that anyone can provide as an assist here?

    • robinwilson16

      In reply to Nic:

      Hello Nic

      Just a thought but could the Location service be disabled on your PC?

      You could check the settings in Settings > Privacy > Location

      Just an idea.


      • Nic

        In reply to robinwilson16:

        Tne Location services were enabled, but still no dice

        I ended up spinning up a VM on my laptop and going through steps 1 & 2. As soon as work starts on Step 2 then the Android app crashes, but the UWP one works just fine.

        To say this stuff is finnicky is an understatement. I even copied over the project from one machine to another, just to see if was a copy pasta problem for me, but got the exact same results, which indicates to me that there's either something up with the software, or funky in windows.

  32. Brett Barbier

    So here's a crucial question - after I win one of these Surface Studios (I'm being a positive thinker!), which I assume will be the i5 8GB model, could I upgrade it to the next model up (i7 with 16GB) by paying $500 out of pocket?

  33. Erfan Mehrvash

    I am struggling with first challenge. Please help me.

    I have many many ERROR.

    • robinwilson16

      In reply to Erfan Mehrvash:

      Hello Erfan

      I had a similar issue the first time I tried to do step 1 which happened after receiving a warning when Visual Studio was attempting to create a new project and it seems it didn't copy all the required DLL files for some reason. I then started with another new project and it worked the second time.

      Also it looks like Visual Studio has pending updates (orange flag) so you could try updating and then starting a new project.

      Good luck!

  34. Jay Kimble

    I finished step 2 Monday night, and have been waiting since then to get step 3. I realize that I needed to wait 24 hours for a response and then 3 days for it to unlock.. (but it's been a busy week).

    Is there anyway you can help me out?

    Jay Kimble

    • hm-thurrott.com

      In reply to Jay Kimble: FYI:
      • 24-hrs & 72-hrs are concurrent
      • See Tina's post below; "your" step-3 will have a count down for when you'll have access to the next step (and by implication that step-2 was successfully completed (sooner than 24-hrs).

  35. gf

    in Exercise 2, Step 19. I get an error message. The first line of the error message says "Unable to activate Windows Store App" Then it has what appears to be the GUID for my app followed by this text "The CoolBreeze.UWP.exe process started, but the activation requested failed with error 'The app didn't start'. 

    Then there is an OK button and a Help button. When I click on the help button I get taken here - https://msdn.microsoft.com/query/dev15.query?appId=Dev15IDEF1&l=EN-US&k=k(vs.debug.error.app_activation_failure);k(TargetFrameworkMoniker-.NETCore,Version%3Dv5.0)&rd=true This page does not appear to really be related to my error since there are no error numbers and when I looked in the event log as suggested, I could not find anything related to what the page was telling me. I am running Windows 10, VS 2017 Community Edition on an HP Envy laptop that is about 1.5 years old. I would really like to complete the challenge but I am not sure how to get past this error so that I can finish Step 2 and receive Step 3

    I have reviewed all of the steps in Exercise 2 and did not find any mistakes.

  36. mdb17

    I am also running into an issue when trying to submit the challenge. Whenever i click the submit but in the app i get the following error: An unhandled exception occured.

    • YEHUDA

      In reply to mdb17: Try cleaning your solution

      • jt5

        In reply to YEHUDA:

        Cleaning has not worked for me. I have poked around further and believe the issue is related to a mismatch in an assembly reference to Newtonsoft.json. I have not figured out how to resolve it yet- but it seems to be looking for something from json that is not there. Which seems to fit with the error. If I find a solution I will post.

  37. Cristian Rodriguez

    Hi all,

    First of all I want to mention the challenge has been great. However, I've run into a few issues, hope you can help out.

    I completed step 3, but when submitting it hangs and throws an exception in App.g.i.cs:


          UnhandledException += (sender, e) =>


            if (global::System.Diagnostics.Debugger.IsAttached) global::System.Diagnostics.Debugger.Break();



    I can't seem to move forward...

    Thanks in advance for any help.

  38. Bruce Lane

    I have completed Part 3 right up to submitting the code. At that point I get an unhandled exception error.

    The mobile center shows the following crash info:

    SubmissionInformation+<SubmitChallengeAsync>d__19.MoveNext ()

    System.NotImplementedException: The method or operation is not implemented.

    The method or operation is not implemented.
    • 1 SubmissionInformation+<SubmitChallengeAsync>d__19.MoveNext ()
    • 2 ExceptionDispatchInfo.Throw ()
    • 7 SubmissionInformation+<<get_SubmitChallengeCommand>b__18_0>d.MoveNext ()
    • 8 ExceptionDispatchInfo.Throw ()

    Any help would be appreciated.

  39. YEHUDA

    I succesfully submitted and got the finished message but never recieved a confiramtion email, this was a week ago and now i reran the project and submitted again.

  40. Dan Hartwigsen

    Oh well, gave it shot... and maybe learned something along the way. In the end, succumbed to all the errors. Wasn't too bad the first time through but got stuck on Step 3, so decided to restart fresh, then got new errors I didn't have before... 'no reference for system.objectmodel', 'must install Microsoft.BCL... (I just did!)'... But I resign, thanks anyway.

    • techieg33k

      In reply to Dan Hartwigsen:

      The BCL error is just something to be ignored (I decided after hours of research). I'd say almost all of my trouble/errors (there were a LOT of them!) were caused by using different (newer) versions of of Plugins than listed in the screenshots or sometimes just forgetting to do something simple (like when first making changes to UWP I needed to Deploy before trying to run it to see the change). I'll be honest though that these difficulties didn't "run me away" but instead still left me torn between learning C#/XAML to use this or Lua/Corona SDK to use Atom (or another IDE)...

  41. Paul Young

    Can anyone tell me where "Exercise 3 (OPTIONAL): Create an authenticated challenge submission experience" mentioned at https://xamarinchallenge.thurrott.com/step-3 can be found? I'd really like to get an insight into authentication in Xamarin.

  42. cedricl

    Were the winners announced ?

    The email link to the winners does not work for me, landing on a page informing me the challenge closed & please come back may 1st.

  43. Rashid Akhtar

    "Could not load type 'Xamarin.Forms.Xaml.XamlFilePathAttribute' from assembly 'Xamarin.Forms.Xaml, Version=, Culture=neutral, PublicKeyToken=null'."

    I am getting this error everytime I try to run the App. Then I clean the whole solution build it and then it works fine. But after few minutes again this error comes while running the application. Please help how to get over with this permanently.

  44. Rashid Akhtar

    Completed Challenge 2 on 28th April, yet not received email for Challenge 3.

  45. Rashid Akhtar

    I am getting the forecast functionality working for Android, but for UWP its not showing the ToolBarItem to get the forecast for the UWP. Any help is appreciated. I even used break points to debug. The ToolBarITem is working alright for Android, but not for UWP. Please help.

    • techieg33k

      In reply to Rashid Akhtar:

      Did you remember to Deploy the UWP version before trying to run it? I had this exact same issue over and over and then realized I just kept running it which did nothing but use the version currently compiled and installed on my machine. Once I did a Deploy it rebuilt it with the changes and then I was able to run and see it in action.

      • Rashid Akhtar

        In reply to techieg33k: I cleaned the whole solution, built it and then deployed to my local machine which is running windows 10. But still the toolbar item is not working for UWP but I see that it is working fine for Android.

        • techieg33k

          In reply to Rashid Akhtar:

          Not to beat this to death but you are using the Right Click > Deploy on UWP, correct? I kept "deploying" it by clicking on the run button in the toolbar (green arrow then it says Local Machine next to it) when I had the problem you are describing. That is I was doing wrong for 30 or 40 minutes until I reread the entire 1st part and realized where I was going wrong.

  46. Mohammed Thabet Zaky

    Anyone know when we know the winner of the challenge ?

    • techieg33k

      In reply to Mohammed Thabet Zaky:

      I tweeted Brad and Paul this AM about that. Brad said the following:

      "This is a good q, need to compile all the data for who completed it...will know something hopefully soon-ish." so I'd guess we might have to wait post-EDU event tomorrow if Brad or Paul are involved since I'm sure they are busy covering it.

  47. Lerch

    I completed Challenge 2 and I'm awaiting the confirmation email. I'm worried my 72 hour wait won't start until my Challenge 2 is registered as completed. How will I know if my completion is not registered? Did I miss something in the challenge? Waiting!

    • wyldebill00

      In reply to Lerch:

      Look for the post below from Tina with this line of text. ANSWERS -- IF YOU ARE NOT RECEIVING XAMARIN CHALLENGE EMAILS

      The url will be similar to this: https://xamarinchallenge.thurrott.com/step-3/youremail/yourchallengecode

      She also says that there is some checking of your progress when you request that url - if you aren't considered complete for the prior challenge, you can't download the materials for the next one.

      Good luck.

  48. Rashid Akhtar

    Completed step 1 , when will I receive instructions for step 2. Do I need to to send my completion status to anyone ? If yes, then who?

    • James Toalu

      In reply to siko:

      I cleaned the solution in addition to modifying the Min Version and Max Version, but it did not solve the problem.

      Which version of Xamarin Forms do you use?

      Please see the screenshot below for more information.

  49. timmiller

    Finally got an email with Step-2. Was successfully able to complete it and got functioning code on the UWP. But Android has still been a pain point for me and I am never able to get the Android emulator up and running. These are my current warnings that seem to be crashing the deploy. I'm hoping I can still move on to Step 3.


    Warning The referenced component 'Xamarin.Android.Support.Animated.Vector.Drawable' could not be found.

    Warning The referenced component 'Xamarin.Android.Support.Compat' could not be found.

    Warning The referenced component 'Xamarin.Android.Support.Core.UI' could not be found.

    Warning The referenced component 'Xamarin.Android.Support.Core.Utils' could not be found

    Warning The referenced component 'Xamarin.Android.Support.Fragment' could not be found.

    Warning The referenced component 'Xamarin.Android.Support.Media.Compat' could not be found.

    Warning The referenced component 'Xamarin.Android.Support.Transition' could not be found.

    Warning The referenced component 'Xamarin.Android.Support.v7.AppCompat' could not be found.

    Warning The referenced component 'Xamarin.Android.Support.v4' could not be found.

    Warning The referenced component 'Xamarin.Android.Support.v7.CardView' could not be found

    Warning The referenced component 'Xamarin.Android.Support.v7.MediaRouter' could not be found.

    Warning The referenced component 'Xamarin.Android.Support.v7.Palette' could not be found.

    Warning The referenced component 'Xamarin.Android.Support.v7.RecyclerView' could not be found.

    Warning The referenced component 'Xamarin.Android.Support.Vector.Drawable' could not be found.


  50. j3ffc0ll1ns

    So what began with great enthusiasm has been replaced with a great deal of disappointment.

    This challenge seemed an ideal way to become exposed to the tool and the concepts behind replacing the other toolsets we use with Xamarin.

    Myself and 5 other developers in our office attempted the challenge and none of us have been able to get past the first challenge. We are not Microsoft Visual Studio experts so we had hoped following the provided instructions would be sufficient.

    Looking down through this blog I can see the errors we encountered (compile/deployment) are a common experience with a number of folks (even some who indeed ARE Visual Studio experts) so I am not sure there is value in reiterating the same issues again.

    My take away from this experience is the Xamarin development environment is so delicately fragile that the slightest change in any of the myriad of components needed results in a 100% dead stop in progress. For a production software development shop, that is a death sentence.

    Perhaps some sort of Visual Studio environment analyzer or configuration validation comparing what is needed for successful Xamarin development to what currently exist would help.

    In the meantime the limited amount of time we had set aside to learn Xamarin has now been exhausted and we have to get back to our full time activities.

    I will keep looking for something that addresses this concern, and sincerely hope to see some progress in this area soon.

    There is great promise here.

  51. jedlicki

    Class WeatherHelper

    post  HttpClient client = new HttpClient();

    URL = http://traininglabservices.azurewebsites.net/api/weather/current/city?cityName=Amsterdam&countryCode=HL

    404 error from service

    +  $exception {System.Net.Http.HttpRequestException: Response status code does not indicate success: 404 (Not Found).

      at System.Net.Http.HttpResponseMessage.EnsureSuccessStatusCode()

      at System.Net.Http.HttpClient.<GetContentAsync>d__32`1.MoveNext()

    --- End of stack trace from previous location where exception was thrown ---

      at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)

      at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)

      at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()

      at CoolBreeze.Helpers.WeatherHelper.<GetCurrentConditionsAsync>d__0.MoveNext()

    --- End of stack trace from previous location where exception was thrown ---

      at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)

      at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)

      at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()

      at CoolBreeze.MainViewModel.<RefreshCurrentConditionsAsync>d__29.MoveNext()} System.Net.Http.HttpRequestException

    • Lerch

      In reply to jedlicki:

      Your WeatherHelper should look as follows (taken from Exercise 4, point 7) :-

      namespace CoolBreeze.Helpers


         public class WeatherHelper


             public async static Task<WeatherInformation> GetCurrentConditionsAsync(string cityName, string countryCode)


                 string url = $"http://traininglabservices.azurewebsites.net/api/weather/current/city?cityName={cityName}&countryCode={countryCode}&registrationCode={App.RegistrationCode}";

                 HttpClient client = new HttpClient();

                 var response = await client.GetStringAsync(url);

                 var result = Newtonsoft.Json.JsonConvert.DeserializeObject<WeatherInformation>(response);

                 return result;




  52. wedumas

    I am still getting email to start step 1. Had to buy larger SSD to install VS. Then one error after another. Fixed those.

    Now stuck with these warning and cannot move on; so starting over again:

    Severity Code Description Project File Line Suppression State

    Warning  The $(TargetFrameworkVersion) for Xamarin.Forms.Platform.dll (v7.1) is greater than the $(TargetFrameworkVersion) for your project (v6.0). You need to increase the $(TargetFrameworkVersion) for your project. CoolBreeze.Android F:UserswedumDocumentsVisual Studio 2017ProjectsCoolBreezeCoolBreezeCoolBreeze.AndroidCoolBreeze.Android.csproj  

    Warning  The $(TargetFrameworkVersion) for Xamarin.Forms.Platform.Android.dll (v7.1) is greater than the $(TargetFrameworkVersion) for your project (v6.0). You need to increase the $(TargetFrameworkVersion) for your project. CoolBreeze.Android F:UserswedumDocumentsVisual Studio 2017ProjectsCoolBreezeCoolBreezeCoolBreeze.AndroidCoolBreeze.Android.csproj  

    Warning  The $(TargetFrameworkVersion) for FormsViewGroup.dll (v7.1) is greater than the $(TargetFrameworkVersion) for your project (v6.0). You need to increase the $(TargetFrameworkVersion) for your project. CoolBreeze.Android F:UserswedumDocumentsVisual Studio 2017ProjectsCoolBreezeCoolBreezeCoolBreeze.AndroidCoolBreeze.Android.csproj  

  53. hm-thurrott.com

    Waited for a a reply via '[email protected]' about my port-registration/first-challenge email being re-sent , but no response so far. Time-frame to complete all challenges in time for the contest is nearly here; re-posting my query here; how do I arrange to get my first/confirmation email resent?

    Update: 4-hours later: Saw post by "Tina Alpha Member #21" regarding accessing the steps directly using URLs and entering the login or POST the credentials. This has got me at least going on "Step 1" now; hopefully the rest will follow.

    Hopefully there was nothing else in that first response email that I will need?... HM

    Update: 1-day later: Completed the Step-1 exercises

    Update: 2-days later: Have yet to receive my step-1 completion email

    Update: 3-days later: My direct URL link to step-2 is still not working.

    Update: @ 2017-04-24 12:32: Still waiting for a reply to any of my posts or [email protected] emails. I am presuming that since my I'm able to access the URL for step-1 with my email/code I am registered.

    Is the "24-hr" and "72-hr" tasks manually done? Is someone down with the flu? I is my email too complex (I'm use sub-addressing and it is longish...)?

    Update: @ moments later; 12:39: Wouldn't you know it; Step-2 URL is now working! Onto finishing it up!

  54. etturbo

    Stuck on Step 2. The app will not display the Forecast weather data.  I have re-done the code several times and resolved all the errors I was getting. Both the Widows UWP and android versions run fine and do not break anymore, but they will not display the data? any suggestions?

    UPDATE: I rebuilt the app from the ground up and did several save file versions as I went. I only had to go back twice and I succeeded getting the app to work properly. Looking forward to getting my Step two completed email.

    Anyone having trouble, I would recommend perseverance! It was quite frustrating at times, but I am a complete novice at any kind of coding, so when I got it to work, it was very satisfying.

  55. cedricl

    I successfully did part I a few days ago.

    Since then, Windows 10 Creators update happened, then updates to Visual Studio 2017.

    I opened my solution today to do the Xamarin Challenge part 2, but Visual Studio crashed, even after the updates.

    A repair later, then a full uninstall/reinstall later, I can't get the solution to work.

    I get dozens of build errors such as:

    3>C:Program Files (x86)MSBuild15.0Microsoft.Common.targetsImportBeforeMicrosoft.Net.CoreRuntime.ImportBefore.targets(17,3): warning MSB4011: "C:Program Files (x86)MSBuild15.0.NetCoreRuntimeMicrosoft.Net.CoreRuntime.Settings.targets" cannot be imported again. It was already imported at "C:Program Files (x86)Microsoft Visual Studio2017EnterpriseMSBuild15.0Microsoft.Common.targetsImportBeforeMicrosoft.Net.CoreRuntime.ImportBefore.targets (17,3)". This is most likely a build authoring error. This subsequent import will be ignored. [F:devLabsCoolBreezeCoolBreezeCoolBreeze.UWPCoolBreeze.UWP.csproj]

    Even starting back from scratch part One, I get 280 errors and 6 warnings at step 6 (!)

    In Solution Explorer, right-click the CoolBreeze solution and select Build Solution to build the solution. Confirm that the solution builds without errors.

    Following the advice of code IDE0006 I get for CoolBreeze.UWP_Compile_bf79ec46.designtime.log:

    Target "DesignTimeMarkupCompilation" in file "C:Program Files (x86)Microsoft Visual Studio2017EnterpriseMSBuildMicrosoftWindowsXamlv15.08.2Microsoft.Windows.UI.Xaml.Common.targets":

     Task "CallTarget"

       Target "GetXamlCppIncludeDirectories" skipped, due to false condition; ('$(ManagedAssembly)'=='false' and '$(XamlCppIncludeDirectories)' == '') was evaluated as (''=='false' and '' == '').

       Target "DesignTimeMarkupCompilationCT" in file "C:Program Files (x86)Microsoft Visual Studio2017EnterpriseMSBuildMicrosoftWindowsXamlv15.08.2Microsoft.Windows.UI.Xaml.Common.targets":

         Task "MakeDir"

         Done executing task "MakeDir".

         Using "CompileXaml" task from assembly "C:Program Files (x86)Microsoft Visual Studio2017EnterpriseMSBuildMicrosoftWindowsXamlv15.08.2Microsoft.Windows.UI.Xaml.Build.Tasks.dll".

         Task "CompileXaml"

           F:devLabsCoolBreezeCoolBreezeCoolBreeze.UWPCoolBreeze.UWP.csproj : XamlCompiler warning WMC1006: Cannot resolve Assembly or Windows Metadata file 'System.Runtime.dll'

           The previous error was converted to a warning because the task was called with ContinueOnError=true.

           C:Program Files (x86)Microsoft Visual Studio2017EnterpriseMSBuildMicrosoftWindowsXamlv15.08.2Microsoft.Windows.UI.Xaml.Common.targets(204,5): Xaml Internal Error warning WMC9999: Type universe cannot resolve assembly: System.Runtime, Version=, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a.

           The previous error was converted to a warning because the task was called with ContinueOnError=true.

           Build continuing because "ContinueOnError" on the task "CompileXaml" is set to "True".

         Done executing task "CompileXaml" -- FAILED.

    This is a nightmare. What can I do ?

  56. JoeyPanda

    I've run into trouble with just the setup.

    When I go to the VS Installer under Emulators neither The Android or WIndows Mobile show up. I made sure I installed the Xamarin. I've checked under other areas. I'm at a loss.

    Probably won't finish the challenge before the contest is over, but that's ok. I'd still like to try.

    I am using the community version of 2017

  57. bggnet

    Getting stopped at the Android Emulator. The Emulator appears to be running OK after a minute or two, but the project won't deploy. After about 20 minutes the build is still at:

    1>C:Program Files (x86)Androidandroid-sdkbuild-tools23.0.3zipalign.exe 4 "C:ProjectsLabsCoolBreezeCoolBreezeCoolBreeze.AndroidbinDebugCoolBreeze.Android-Signed-Unaligned.apk" "binDebug\CoolBreeze.Android-Signed.apk" 

    Hard to believe it is supposed to take longer than this.

  58. DavidSlade

    I am on the final stretch: Part 3. But I cannot see Crash Data in the Visual Studio Mobile Center because the app crashes when running in Android Release mode, which is supposed to upload crash data. (How ironic).

    How do I find why it crashes in Release mode? It works fine in Debug mode. I just get the message on the emulator:

    Unfortunately, CoolBreeze.Android has stopped.Unfortunately, CoolBreeze.Android has 

    • techieg33k

      In reply to DavidSlade:

      I haven't gotten it to upload to the VS Mobile Center ether and after some taking stuff in and out I got to the point where it would crash like that even with the "crash" code removed. I ended up going through all the files and removing everything from Part 3 from the project, doing a Clean on the project, then Build, and then closed/opened VS and launched it - and it worked again...now off to try and start Part 3 all over again.

      UPDATE: I also found the code in Part 3 to work perfectly if I made sure following Packages were 0.7.0 (as shown in the Challange) and NOT the 0.8.1 that I installed to start. If you had installed anything other than 0.7.0 go back in and change the following to 0.7.0: Microsoft.Azure.Mobile, Microsoft.Azure.Mobile.Crashes, and Microsoft.Azure.Mobile.Analytics - I had to do this and afterwards it worked perfectly with the EXACT code listed in Part 3.

    • RamblingGeek

      In reply to DavidSlade:

      You need to remove the code which breaks it. It didn't upload for me either. I read the documentation for the mobile centre and added the following:

       MobileCenter.Start("{APP CODE}", typeof(Analytics), typeof(Crashes));

      In the Andrioid project, in the file MainActivity.cs before the line :


      I don't think the line above works any longer, I assume because of changes in the platform.

  59. cat

    In reply to James Toalu:

    So... it SHOULD be up in the top... (light grey bar... with "...") I had the same issue and did what siko mentioned AND updated a bunch of packages... and did the resource hack mentioned below... and corrected the typo mentioned below... I'm not sure which one really did it, but I think that in the instructions where the icon resources go may be 'iffy'...

    oh... and I did various target changes as siko also mentioned below

    • James Toalu

      In reply to cat:

      I modified the Min Version and Max Version in addition changing to the Dark theme, but it did not solve the problem.

      Which version of Xamarin Forms do you use?

      Please see the two screenshots below for more information.

  60. Randy Baker

    I have completed step 1last night. How did I sent my status or completion?

  61. hm-thurrott.com

    A comment about a possible error in the "official rules" for completing this challenge and qualifying for the prize draw.

    Re: https://xamarinchallenge.thurrott.com/rules

    Quote (italics mine): 3. Campaign Period: Entries will be accepted online starting on March 16, 2017, 12:00 am Eastern Standard Time and ending April 30, 2017, 12:00 am Eastern Standard Time. All online entries must be received by March 31, 2017, 12:00 am Eastern Standard Time.

    To me there could be two ways to interpret the "March 31" date:

    1) Its wrong and should have been "April 30", being the last day to complete challenge #3

    2) It is referring the last day one can "register" for the challenge at the URL "https://xamarinchallenge.thurrott.com/#registration".

    I registered on April 1st after some initial difficulties and having presumed #1 scenario above - an error in the rules. My confirmation webpage implied that I was registered for both the challenge and prize draw (still haven't have anyone respond to my missing step-1 email query I posted earlier https://www.thurrott.com/forums/microsoft/dev/thread/xamarin-challenge#99094 or email to [email protected]).

    While I hope to work the challenges as an exercise in Xamarin; it be nice to clarify if I am officially able to enter the draw (once I've completed all the challenges...)

    Since the registration page is still accepting registration as April 22nd, and still promoting winning the Surfaces, I presume March 31st date is error.

  62. Randy Baker

    my android. Emulato r list is much smaller. How can I get a recommended AVD?

  63. SilentHero117

    I just completed the first step yesterday and have not received the confirmation email within the 24 hour timeframe.  One feedback I would like to add is to have the app receive and display a confirmation message with a reference number.

  64. wedumas


    Windows 10 Pro Build 16179 arrived; Restart required. Then I shutdown PC. Turned PC on.

    Then ran Visual Studio Community 2017 v15.1. Did VS updates for (6403.7) Release.

    Exit VS. Move visual studio files from onedrive to the harddrive. Restart PC.

    Run VS change file paths. Load CoolBreeze. Do Nuget packages updates. ReBuild Solution.

    CoolBreeze.UWP missing file "packages.config". Copy CoolBreeze/packages.config to CoolBreeze.UWP.

    Then run CoolBreeze.UWP and it WORKS!!!

    Set startup to Android

    Run: 5" KitKat (4.4) XXHDPI Phone ...

    There were deployment errors. Continue? Yes or No

    ??? ...

    Select: VisualStudio_android-23_arm_phone (Android 6.0 - API 23) from the list

    Run and wait for the emulator a looooooooooooong time (minutes) before apps appear.

    Click the CoolBreeze icon and it WORKS!!!

    VS is a hard to use and learn IDE. I did a weather app with HTML5 and JavaScript in a few hours.

    I began the Xamarin Challenge on April 1 and days later; requires a VS reinstall but crashes because the SSD is full; get a larger SSD; clone Win 10 to the new drive; install VS again; put up with errors and warnings getting to end of step 1 with nothing running.

    Start over from the beginning again and today I have Step 1 UWP and Android running.

    Hope to inspire people to push on with the Xamarin Challenge. It can work.

  65. Asif Siddiqi

    I completed step #2 two days ago. Unfortunately, as I can see a consistent issue in the messages, the emulator experience is really flaky. I was only able to run the Android version on the built in ARM emulator - which worked for Step 1 as well as step 2. But even after running both WUP and Android version - using both the forecast and "now" based on location detection, I have not received the completion email. Wondering if there is any specific requirement to use a specific emulator version. I am using ARM API level 23. Thanks.

  66. robinwilson16

    It really is hard to be sure whether I have completed the Xamarin challenge or not as on 12th I received an email to tell me I had completed the whole challenge (a week after actually completing it in Visual Studio) as well as a link to a feedback survey. However a week later on 18th I received an email to tell me I had completed step 1 and should start step 2 (2 weeks after completing everything).

    Since Windows 10 upgraded itself neither the Windows app or the Android app will work now so I'm hopeful I don't need to repeat anything.

  67. ArmoredDragoon

    I just spent three hours trying to troubleshoot why the deployment was failing, and never could get it to work with the built in emulator. I'm running creator's update of Windows 10, fresh install, fresh visual studio install, no registry tweaks or anything. There shouldn't be any reason this should fail.

    I did notice two major problems while troubleshooting:

    • Hyper-V doesn't correctly set up its network drivers, so the emulator doesn't even run correctly. The VM freezes before the kernel even finishes loading.
    • As far as I can tell, the visual studio setup isn't able to properly register the emulator with ADB (your first clue of this being the problem should be that no debug messages show up in the bottom pane. And given that there are no actual debug messages, finding out that this is the actual problem will be difficult even for seasoned developers.)

    After this point, anybody who wants to try to use this for production should just stop right here and stick with other tried and tested IDEs. The first problem requires deleting the virtual switch, deleting the Hyper-V NIC drivers, and then re-creating the virtual switch and configuring the emulator to use it.

    I honestly have no idea how to fix the second problem because VS just doesn't do anything to tell you what exactly is going on here.

    Nonetheless, I pushed on, and I do have a workaround that allows you to complete the challenge.

    This will solve almost any deployment problem you should ever run into with this (IMHO quite alpha) Android IDE which worked for me: Connect a real Android phone to your PC, enable developer mode on it, and then go ahead and build. Your app will show up on your phone and you can resume from there. Feel free to remove Hyper-V if, like me, you prefer other VM software (IMO Hyper-V is the Ford Pinto of hypervisors...they just included it with Windows like a cheap kids toy in a cereal box. The least Microsoft could have done is support VT-x/AMD-V passthrough so that you can have other hypervisors installed along with it; alas, they didn't. Did I mention VMware DOES support this? Too bad Windows doesn't support making THAT the host VM...)

    Alternatively, (and I haven't tried this route) install Android Studio and use its emulator, or any other Android emulator that gets properly recognized by ADB.

    Don't get me wrong, Visual Studio is a very nice IDE, but they've got a loooooooong way to go if they want to make a true "write once, run anywhere" environment (and to be honest, historically that never works out very well.)

  68. jsc_iii

    I've gotten to the point of testing the results of Step 1.

    But, all I got was the "Welcome to Zamarin Forms" message, not the weather in Amsterdam. So I rechecked everything and now when I try to run it "Set as Start Project" is grayed out.

    So, any hints about what is wrong. Or in the alternative, can you tell me how to delete everything and start over.

    BTW, I almost didn't get this far because it took me a while to realize that the Android emulator wasn't running because I have to be running as an Admin to start a virtual machine.

    • hm-thurrott.com

      In reply to jsc_iii: Be sure you "Deployed" your newly compiled code to the WinMobile emulator prior to running, especially if the you haven't restarted the VM emulation (vs. saving it). You "run" action against the emulator will run the currently present code.
      The Android emulation appears to always deploy the latest compile. (or so it has seemed to me).

      Update 2017-04-28 06:38: I've taken to starting the "Visual Studio Emulator for Android..." and ensuring that the appropriate emulation is launched (and even running) prior to deploying or debugging the app. And even then I'm might restart VS if it gets out of "sync" as to whether or not the emulation needs a redeployment.
      For WinMobile, I use the Hyper-V MMC to launch the VM, and also monitor the Android VMs as started.
      BTW: For others reading this post, be sure to scan for other post discussing Hyper-V issues for non-Pro versions of Windows re: running as Admin.
  69. Starzuft

    Having difficulty installing Visual Studio. The two checkboxes under the Emulator category do not exist. Neither in the Community nor Pro version of Visual Studio when downloaded. Are there further instructions?

    • hm-thurrott.com

      In reply to Starzuft:Also, this caught me; if you are running a VM to run your VS, then you'll won't be able to run a nested instance of the Hyper-V VMs.

      There probably a way to get the VM instance of VS to talk to the host it is on, but I haven't figured out how make it work.In any case it would involve installing the emulators separately, and I've only figured how to get the Android ones to work (they have an clear cut independent installer).

    • Elindalyne

      In reply to Starzuft:

      You need to enable virtualization in your bios. If that's already enabled you need to install Hyper-V.

  70. Tim Daborn

    Ok I THINK I have completed the challenge!!  I assume there us a confirmation email, so I shall wait for that.

    Thanks to those who have posted their progress and solutions – it was helpful.  For my experience I had numerous errors especially around the Android emulator. 

    Although I only installed VS 2017 a few weeks ago - I found checking for updates and installing them (Look for the flag in the topmost corner of VS) fixed some of earlier problems.

    But still the Android emulator would not play ball, but restarting the pc sometimes sorted this out, but it became particularly difficult after I added the crash support dlls and right at the end I had to give up on it.  Although I did get it to upload some crash reports.

    To make my final submission I had to overcome an error in the UWP version.

    It may be the week’s delay between the different parts that caused this issues and the vagaries of Nuget. The upload was failing on a discrepancy between 2 different versions of the Json package, which somehow had crept into the project. Installing over 40 updates in Nuget resolved this.

    Many thanks for running this challenge –this was very useful and worthwhile. I just wish modern development did not feel like trying to dance on a mile high stack of chairs with a leg missing on the bottommost one!

  71. RamblingGeek

    Ok... I have completed the challenge.... Good Luck.


  72. Codesmith

    Just wanted to say congrats to those of you rolling in yesterday and today that have completed all 3 phases of the awesome Xamarin Challenge! Hope you had fun, learned alot, and you now have all kinds of cool ideas for cross platform apps of your own! (And of course CoolBreeze is yours to adapt and enhance forever, too...coo!)

    Anyway, congrats so far and good luck! I would LOVE to be a winner of one of the Surface Studios! But, it won't be me...maybe you? :)

  73. BarryWallis

    At the end of Part 1 when I run the finished app, the UWP version runs fine; however, the Android version starts and puts up a modal dialog that says, "Unfortunately, CoolBreeze Android has stopped."

    Any ideas what I can do to resolve this?

  74. darrix

    Hi, I completed the first phase of the contest.  I didn't receive the email for the second phase, but did receive an email for the third phase of the contest, followed, a few hours later, by another email indicating I had completed the contest, even though I've only completed the first part.  How do I get this straightened out?


  75. Glyn


    This one has got me foxed.

    I’ve followed the Part 2 instructions to the letter.

    Everything works fine in the Android App emulator.

    I have no access to iOS so I can’t report anything about that version of the app.

    However, the UWP app (deployed to either the Emulator, Local Machine or Device) does not show the FORECAST ToolbarItem or the LOCATION and NOW icons.

    The result is that despite completing Exercise 3, the UWP version looks no different than it did at the conclusion of Exercise 2.

    I’ve tried cleaning the solution, refreshing references, restarting Hyper V and deleting the app. I rebuild and redeploy the UWP app and nothing has changed from the interface at the conclusion of Exercise 2.

    This was done on a fully patched 1607 current release PC.

    I've also tried this on the latest Insider Fast Ring 1703 build on a laptop. I got the same UWP issue and additionally the app would deploy, but not open/run on the Android emulator.

    Oh dear. Any clues?


    • adityanag

      In reply to Glyn:

      Heh, read the comment thread directly below this one..

      • Glyn

        In reply to adityanag:

        Yup, saw that. I was asked to post anyway by @Geeksmith on twitter, so I obliged.

        • adityanag

          In reply to Glyn:

          you don't see the icons in the Windows Mobile Emulator either? That's a new bug - I can see the icons in the Emulator, but not on the desktop app.

          • Glyn

            In reply to adityanag:

            I've used a fresh install of Visual Studio 2017 Community on both machines, alongside existing Visual Studio 2015 Community installations.

            I wonder if that has any implications?

            • Codesmith

              In reply to Glyn:

              Yes, the "TabItems not showing" on UWP Desktop is a known Xamarin Forms bug in the last week or so...however if you don't see the TabItems on Windows Mobile, my guess is you're looking at the top, and not the bottom AppBar...I'll bet if you tap the [...] at the bottom AppBar on Windows Mobile you will see the TabItems...check and see. :)

              • Glyn

                In reply to Codesmith:

                Ok, I'm not sure what changed, but...

                VS2017 updated today. Nothing was listed/documented, but it was a long, long restart. Version unchanged at 15.0.0+26228.9, so it must have been an extension(s) update rather than product.

                Anyhow, after rebuilding the Xamarin Challenge project, on my 1607 14393.969 PC, I now get the Forecast icon and functionality in the usual bottom location on the Windows emulator and physical device, but not on the local machine desktop app (as per the bug). Icons do not appear for Location and Now. I'm not sure if they're supposed to, but why supply the assets otherwise?

                On my 1703 15063.0 machine the Android App deploys and opens, but when you click "Now" the app crashes with the message "Unfortunately, CoolBreeze.Android has stopped.".

                Two suggestions.

                1) It might be useful to mention the Xamarin Forms bug in the Part 2 and 3 documentation.

                2) How about providing pictures of what the app should look like for all the target generic devices: Android Phone; iPhone; Windows Phone; and Desktop?

                • Codesmith

                  In reply to Glyn:

                  Good comments. I actually believe the "ToolbarItems" bug note was supposed to be added to the content. I'll follow up.

                  RE: The images/icons that don't show. Can you clarify "where" they don't show? Is this still ONLY on Windows Desktop version?

                • Glyn

                  In reply to Codesmith:

                  In the Android app there are icons above the "LOCATION" and "NOW" text labels.

                  Since icons were also included for the UWP app I assume they're supposed to appear in a similar position, but they do not. There are just the words "LOCATION" and "NOW" at the top and the forecast icon at the bottom. The behaviour is the same in the emulator and on a physical phone. In the desktop app there are no icons and no forecast as previously discussed.

                  Hence my suggestion that the documents include pictures of how each generic platform device should look at the end of significant UI modification.

                • Codesmith

                  In reply to Glyn:

                  Ah, okay, I get it. The Challenge got finalized the day VS2017 moved to Release and the icons always showed up in 2017 RC...hoping a VS2017 update would resolve the bug, but not yet. Now that we see UWP Desktop having this issue would be good to make a note and add in. I think originally they were going to require submission only via iOS or Android but I convinced them to allow UWP folks to submit as well...my bad (sort of) but I did think we needed a scenario where you didn't need an emulator.

  76. andrewtechhelp

    Anyone else found this issue?

    I've successfully completed Part 1 and got the email to complete Part 2. I've got all of part 2 working as expected, but for whatever reason, it hasn't triggered in the system that I've completed Part 2 and so I haven't got any of the emails for Part 3 :'(

    • Patrick Abadi

      In reply to andrewtechhelp:

      I'm in the same boat. Haven't received anything to start Part 3 in over 24 hours.

    • andrewtechhelp

      In reply to andrewtechhelp:

      So last night I sat down and got this working. I'm assuming that the calls to the service are what triggers the system to know if you've completed a part of the challenge or not. So I loaded up the apps on each platform and kept using them over and over until I had ensured there'd been probably a dozen or more calls to each of the 4 services you have at the end of part 2. Sure enough I woke up this morning and part 2 was completed. :)

  77. kiwiglen

    Hi, I'm having a problem that I was hoping someone could help.

    I'm up to the Exercise 5 - Test the App of part 1, the build is OK but I get a deployment error. The error is "The referenced component 'System.ObjectModel' could not be found.

    I've checked that I followed all the steps correctly but I can't see what is wrong, anyone got any ideas?


    • Codesmith

      In reply to kiwiglen:

      That is a pretty generic message and could be anything or nothing. Can you try:

      1. Copy the entire CoolBreeze solution somewhere for backup

      2. Close the entire solution in VS 2017

      2. Open the solution in File Explorer and removing any bin and obj folders in all four (4) projects

      3. Open the solution and do a rebuild

      Let me know!

    • techieg33k

      In reply to kiwiglen:

      I had this happening with deploying the Android version (Exercise 3, Step 18) though it might still apply to your problem. Long story short I've fixed this by Right-click on References (under the CoolBreeze.Android part) and choose Add Reference then I had to browse to the following location (adjust yours as needed for the correct path) E:\\Projects\\CoolBreeze\\CoolBreeze\\CoolBreeze.Android\\obj\\Debug\\linksrc\\System.ObjectModel.dll and then I did a Right-click of the CoolBreeze.Android and selected Rebuild. After that was done I saved, closed VS2017 and then went back in and it no longer gave me this error.

      NOTE: For some reason I can't do single backslash, so I used double above in my location.

  78. Codesmith

    Hey folks, if you are experiencing an issue when first provisioning the Xamarin Forms app, with a dialog related to a "Package Error" for "Microsoft.NetCore.UniversalWindowsPlatform", this is almost always related to a VS2017 workload installation problem.

    Here is the (most common) quick fix:

       1. Close the dialog and let the process finish

       2. Go to the CoolBreeze (Universal Platform) project and open project.json.

       3. See if you are missing the following reference in the dependencies node: "Microsoft.NETCore.UniversalWindowsPlatform": "5.1.0"

       4. If you are, add it in to the node, make sure your JSON looks right

       5. Close the entire solution and reopen it

       6.You should be good to go!

    Let me know!

  79. lwetzel

    I don't get it.  I have not really completed the second part and have had nothing but fits with the Simulators as well as trying to run the app on my desktop.  Have not attempted Exercise 3 in Part 2.

    BUT! I have an email that says I completed and have to wait to start Part 3.  Bet that would go well since I've not finished Part 2.  When I have gotten the android emulator to work I'm seeing the button Forecast button but it blows up.  I don't even see the Forecast button  on the desktop when I try to run it under windows and that is when It runs on windows

    Fails to deploy on anything. 

    IS it just me or are others experiencing a mess?

    • Glyn

      In reply to lwetzel:

      [I'm re-posting my reply as when I try to edit and update an existing post on here, it vanishes!]

      The lack of Forecast button in the UWP desktop app is down to a bug introduced in Xamarin Forms on the day VS2017 'shipped'. The bug is known, but I have not heard when a fix is due.

      I've successfully completed all three parts of the Xamarin Challenge on a 1607 14393.969 PC, but on my Insider Fast Ring 1703 15063.0 machine, the Android App deploys, but the emulator crashes if I try to open it.

      So, it is possible to complete all three parts of the challenge, albeit without the Forecast or Submit functionality in the UWP desktop app.

      There was also a slight glitch with VS Mobile Centre in the error data exercise in Part Three, where data capture did not occur. However, when I returned to the project the next day error capture and reporting was working and refreshed in just a few seconds. I suspect a little time has to elapse between provisioning a new account and all the knitting getting done ready to deliver the goods.

      So apart from a few niggles and one bug, if you're running the current released version of Windows 10 (patched up to date) and using VS2017 with all the right bits installed, the competition is doable in the Android or Windows emulator. I can't comment on the iOS emulator as I don't have rich parents.

      (I ended up sticking with the Android Emulator as the Windows Emulator has a see you next Tuesday of a delay to start up.)

      • Nic

        In reply to Glyn:

        Thanks for posting this. I spent a half hour scratching my head and double checking my work wondering why I could not find the forecast tab on UWP even though it was working just fine on Android.

  80. Glyn

    Just completed Part Three and done the competition submission.

    The crash data is taking a while to show up in the VS Mobile Centre. Thirty minutes have passed so far and it still says "Collecting Data..."

    "Near real time" indeed :-)

    • adityanag

      In reply to Glyn:

      I had a similar experience - the data showed up after about 40 min (when I ran the crashing app 40 min or so after creating my account). Maybe it just takes Mobile Center a little while to wire everything up.

      I've submitted as well.

      Kudos to the team for this challenge. It's been fun, and I've learnt about proper project structure for cross-platform apps. This is very useful cause it's not properly explained when you look for it on random blog posts.

    • Codesmith

      In reply to Glyn:

      Did you make sure the 2nd time you ran the app (after the fake crash) you DIDN'T run with debugger attached? It doesn't send crash data if you are in a debugging session.

      • Glyn

        In reply to Codesmith:

        Yes, a recompile and Ctrl+F5.

        The same again after Exercise Three and my competition entry submission.

        It's been over an hour now and still no sign of the error data.

         I'll try again tomorrow if nothing appears in the meantime.

        • Codesmith

          In reply to Glyn:

          Okay, I agree that the first run could sometimes be flaky for VSMC Crash data. In the past I have repeated this step at times and it shows after just a minute or two. You may want to try that just for kicks, as it will never take more than a few minutes to show up if VSMC gets the info the first time.

          • Glyn

            In reply to Codesmith:

            I tried it again today and the data showed up in a matter of seconds.

            Did nothing different to yesterday when nothing appeared! :-)

            Perhaps it takes time for the knitting to get completed when an account has just been created in the Mobile Centre?

            Anyhow, that's me done and in the draw. Fingers crossed.

  81. lwetzel

    Ok I decided to give this a shot.  Not familiar with C#, or Xamarin. Very little experience with Visual Studio.  But somewhere in the invite it made me think I could do this.

    Right off the bat I noticed in Exercise 2 step 4 I don't match.  Supposedly I am to

    Confirm that the solution appears in Solution Explorer and that it contains four projects:

    • CoolBreeze (Portable) - Contains shared logic for your Xamarin Forms app
    • CoolBreeze.Android - Contains assets, resources, and logic specific to Android
    • CoolBreeze.iOS - Contains assets, resources, and logic specific to iOS
    • CoolBreeze.UWP (Universal Windows) - Contains assets, resources, and logic specific to the Universal Windows Platform (UWP)

    Well I see this in my Solution Explorer

    • CoolBreeze
    • CoolBreeze.Android
    • CoolBreeze.iOS
    • CoolBreeze.UWP (Universal Windows)

    So am I already hozed??

  82. Codesmith

    Folks, if you're having issues (or even misleading warnings) the first time you try and run the CoolBreeze app in the Android Emulator, here are a few tips and tricks:

    1. In general, you can ignore warnings related to "TargetFramework" or "MonoDroid" versions. This is typically (not always, but typically) not the reason you are having issues, and you will actual still see these at times, and are really just "informational".
    2. Some computers have an issue with Hyper-V, where the actual cause of the issue is actually that the Emulator isn't loading or communicating with Hyper-V. 95% of the time you can simply go to Tools > Visual Studio Emulator for Android, and start the Emulator from there, first, and then all your deployments will go perfectly.
    3. IF you think the VS Emulator for Android is slow, it's probably not. The VS Emulator for Android is actually faster (in general) than UWP, the Mobile Emulator, and of course the iOS Simulator. What I have found is the FIRST time you are deploying to the Emulator it takes forever, but it's actually a bogus delay. Instead, try this: Start deploying to the Emulator, then almost immediately go to Build > Cancel Build. The run it again at it will be very fast, and will continue to be very fast.

    Although technically not required, I like to make sure I have API 19, 21, and 23 installed. If you still have issues you may want to update all your Android SDK versions to have at least 21 and 23, and then delete your CoolBreeze solution completely, and start it from scratch. Xamarin Forms will then see they API version it likes.

    Hope you're having fun! It's a cool Challenge, and well worth the effort to become a pro!

  83. Paul Thurrott

    Another follow-up ... I think I'm on the path to fixing this. I did just get the new test app I created to run on both Android and UWP/local machine, but only after I changed the target of the Android version to API 23. I used the built-in (slow) emualtor. And there are still several warnings. But they did come up. Hm.

    • Codesmith

      Paul, in general you can ignore those warnings, as although true, are not typically related to any actual compile issue or emulator scenario. In fact, I almost always have those warning with Xamarin Forms on the lates build with VIsual Studio 2017.

      There is typically (as you said) as possible Android SDK issue, OR I have seen where Hyper V has a hiccup.

      Although I rarely have any issues on my workstations, and the built in VS Android Emulator is SUPER FAST for me, one thing that "often" works for me is:

      1. In VS 2017, go to Tools > Visual Studio Emulator for Android
      2. Start the Emulator directly first, and have it running
      3. Select the Emulator (such as Kit Kat 5") and deploy

      Most of the time this seems to get around it. Let me know if this helps, or if you find any other issues!

  84. Paul Thurrott

    So here's one.

    I'm traveling and I just realized I had completed Step 1 for the CoolBreeze app on a different PC. So I figured I'd just redo it on this laptop. I'm not sure if this is related to the fact that it's running the Insider Preview, but I get the following three errors when I attempt to run the UWP version of the app locally (this is steps 21 and 22 in Exercise 3).

    Severity Code Description Project File Line Suppression State

    Warning The $(TargetFrameworkVersion) for Xamarin.Forms.Platform.dll (v7.0) is greater than the $(TargetFrameworkVersion) for your project (v6.0). You need to increase the $(TargetFrameworkVersion) for your project. CoolBreeze.Android c:userspauldocumentsvisual studio 2017ProjectsCoolBreezeCoolBreezeCoolBreeze.AndroidCoolBreeze.Android.csproj

    Severity Code Description Project File Line Suppression State

    Warning The $(TargetFrameworkVersion) for Xamarin.Forms.Platform.dll (v7.0) is greater than the $(TargetFrameworkVersion) for your project (v6.0). You need to increase the $(TargetFrameworkVersion) for your project. CoolBreeze.Android c:userspauldocumentsvisual studio 2017ProjectsCoolBreezeCoolBreezeCoolBreeze.AndroidCoolBreeze.Android.csproj

    Severity Code Description Project File Line Suppression State

    Warning The $(TargetFrameworkVersion) for Xamarin.Forms.Platform.dll (v7.0) is greater than the $(TargetFrameworkVersion) for your project (v6.0). You need to increase the $(TargetFrameworkVersion) for your project. CoolBreeze.Android c:userspauldocumentsvisual studio 2017ProjectsCoolBreezeCoolBreezeCoolBreeze.AndroidCoolBreeze.Android.csproj

    They're all obviously related. I'll root around, but where can I change the target Framework version to 7.0 so that this deploys and then runs locally?

    I'll also try running it in a Windows phone emulate. I bet that works fine.

    • jeffpro

      In reply to Paul Thurrott:

      Paul, can you try changing the Android settings described in the following post and let me know if it resolves the errors? I should note that I have seen similar errors crop up on my machines for no apparent reason after the Android project built and ran fine the first few times.


      • techieg33k

        In reply to jeffpro:

        I'm getting the same issue Paul is/was, but on Step 18 of Exercise #3 (Part 1). Trying the fix I found on that link:

        1. "Go to C:Program Files (x86)Androidandroid-sdk
        2. run SDK Manager.exe (right-click Run as Administrator if on Windows 10 Pro at least)
        3. Click on Update the Packages. (It will download necessary updates)
        4. Go to Application properties
        5. Set the Target Android version (6 or 7 according to the error).

        I need to let them download the updates over night so I'll reply back tomorrow if that fixed it. I searched all over the web before finding the post here by Paul.

      • Nic

        In reply to jeffpro:

        Given my constant failures with the first attempt at this I started a new project and get the same warnings that Paul was getting. I'm unable to start debugging the android emulator in anything below Marshmallow, whereas previously I could start with KitKat.

    • Paul Thurrott

      In reply to Paul Thurrott:

      Quick followup: I decided to test this with a blank/test Xamarin cross-platform app. And ... same exact warnings, basically, though now there are four of them. Now I'm really confused :)

  85. adityanag

    Xamarin Step 2 - the app works on Android (simulator), iPhone (physical device), and on UWP ... but on UWP, I don't see the location and now icons, and can't see the forecast page either.

    I have copied the icons to the root UWP folder. Not sure why I can't see the forecast page.

    Works perfectly on iOS and Android!

  86. Steve Russell

    In the step:

    Still in App.xaml.cs, replace "<YOUR CHALLENGE REGISTRATION CODE>" with the registration code you received when you registered for the Xamarin Challenge

    Do you think we need to keep the quotation marks since it's a string?

  87. DMAdust

    I registered on the 18th and never received an email. Not in my spam either.

  88. Eric Jutrzenka

    Thought I'd share this link as I found it very helpful with project setup issues:


    It describes a sort of dance you can do with VS to get things running smoothly when setting the project up, reminds me of when I used to work in Eclipse. Worked well for me although I don't have the android emulator working, but haven't look into it yet. I might try and run that part on a real device anyway.

  89. mickeygousset

    So I can't get the UWP app to work. When I try it, it tells me the System.Runtime.dll is missing.  Any thoughts?

    • siko

      In reply to mickeygousset:

      For some reason, the most important package is missing from the UWP project, and can be installed by:

      Install-Package Microsoft.NETCore.UniversalWindowsPlatform

      Or right click on the uwp project, browse and search for Microsoft.NETCore.UniversalWindowsPlatform, and it will run.

    • Eric Jutrzenka

      In reply to mickeygousset:

      I got this error a few times when creating the solution. Creating a new solution fixed the problem for me. Also, this link has some useful info: https://redpillxamarin.com/2016/12/23/202-starting-on-the-right-foot-2/

    • Nic

      In reply to mickeygousset:

      I get the same thing. Also a warning around needing to have Microsfot.Bcl.Build installed. After installing that I get an error saying it can't find the packages.config file.

      • Nic

        In reply to Nic:

        I restarted from scratch, and found that if I started off with VS running as administrator then UWP build worked without an issue.

  90. Saeed212

    I already wrote about this issue and it seems it only affecting me after I registered I did not receive any email

    I thought there are problem with my registration

    but I rechecked my email it is correct and when I want to register again by the same email it is telling me that I am already registered

    Is it ok if I register with another email ?

    • StephenCWLL

      In reply to Saeed212:

      Yup, I had that. I signed up on saturday, but no email reply since. However, I've just signed up with another email address and got the part 1 email within seconds. I suggest trying another email addy if you have one :) Can't start challenge yet though as it wants 40GB worth of VS2017 downloaded and I'm on metered connection during week :/

    • Simard57

      In reply to Saeed212:

      did you check junk email folder?

      • andyj612

        In reply to Simard57:

        Exactly the same thing happened to me.

        I got my XBWW number but no email.

        When I tried to re-register, it tells me I'm already registered.

        Nothing in spam or junk mail folders.

        Anything I can do?


  91. maethorechannen

    Not sure why I need to enter Industry and Company Name when I'm not doing the challenge as part of the day job.

  92. lwetzel

    Ok I have gone all the way through this thing.  Have not been able to get android or UWP deploy on emulators since Part 1. Have only been able to get local Machine deploy.  Of course as others have pointed out there is a but that does not allow the Forecast button in the toolbar or the Submit Challenge either.  Now how am I supposed to get may chance at the prize? 

    • lvthunder

      In reply to lwetzel:

      Figure out the issues with the Android and/or Windows Phone emulator. I had to run the Android emulator manually to get it started then I could run it through Visual Studio.

    • Codesmith

      In reply to lwetzel:

      Yes, sire, here is a workaround that WILL allow the Forecast and Submit Challenge ToolbarItems to show on UWP (Local Machine) do this:

      1. Right-click the CoolBreeze solution and select Manage NuGet Packages for Solution...
      2. On the Installed tab, check the Include prerelease box
      3. Scroll to the bottom of the package list and select Xamarin.Forms
      4. In the Version drop-down, select the latest prerelease package, such as
      5. Run CoolBreeze on Local Machine. You might have some weird label alignment, but your buttons and labels should show.

      Let me know, brother!

  93. AlanMichas

    I finished Part 1 a few days ago and have still not received the link for Part 2. Any advice?

  94. RonH

    I am on Part 1..

    Deploying UWP gives me errors..

    Type universe cannot resolve assembly: System.Runtime, Version=, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a. CoolBreeze.UWP   


    Cannot resolve Assembly or Windows Metadata file 'System.Runtime.dll' CoolBreeze.UWP 

    • siko

      In reply to RonH:

      For some reason, the most important package is missing from the UWP project, and can be installed by:

      Install-Package Microsoft.NETCore.UniversalWindowsPlatform

      Or right click on the uwp project, browse and search for Microsoft.NETCore.UniversalWindowsPlatform, and it will run.

  95. Tom Foran

    I finished Step 2 a few days ago (longer than 72 hours). Instead of receiving an invite to Step 3, I received an email to start Part 1 with the same challenge code.

    I checked the calendar and it's not Groundhog day, but it is April Fools.

    What's happening?

    • Tina

      In reply to Tom Foran:

      We sent an email out to people who registered but never started Step 1 to encourage them to start the challenge.

      We have a situation that may have swept you and others up in this email batch, so please don't panic. We do have a data upload lag between our marketing database and the challenge database. Because of this, some participants who have finished Step 1, 2 and 3 may have inadvertently been part of this email send. 

      I am sure you will get your step 3 invite soon.

      Thanks for your understanding and your participation in the Challenge.

  96. GrizzlyStrong

    I do not know how to proceed. Successfully completed Part 1 of this challenge 2 days ago, but I have not received part 2 yet. Do I need to do something else?

  97. mdjdejesus

    Can't get past part 1. Can't see any way to configure VS 2017 to the requirements on Windows 10 Home.

    Good luck to the rest of you.

    • Dan Hartwigsen

      In reply to mdjdejesus:

      Just do not select to install the emulators in individual components as the instructions say. I wish this would have been clarified for W10 Home too. Then you can still test on Windows (local machine); I actually could still run the android emulator, but I don't know why. And I did get my confirmation email that I completed Step 1.

      • siko

        In reply to Dan Hartwigsen:

        Due to some unfortunate events I had to reinstall my os and didn't switch on hyper-v .... and opted to use x86 emulators for android --> way faster! and yes, uwp test it local machine, all good.

    • siko

      In reply to mdjdejesus:

      You'll need pro (which includes hyper-v).

  98. HenryV

    I have completed Part 2- calling the services for sure.  Still no completion email.  No email for Part 3 (3 days later).  Not sure how to proceed if the application is running fine....

      • dave.erwin

        In reply to Tina: Same here, I got everything working yesterday. I don't remember if there was a submit challenge button in part 1 but I don't see one in part 2. I had to install pre-release nuget packages to get the UWP version working. Not exactly a smooth tutorial experience between that and required adjustments to the android emulator but I guess I'm learning something.

  99. RonH

    I finished Part one yesterday (Android and Windows). How long before I can start Part 2?

  100. BarretBlake

    I'm certain I finished part 2. I went through all the steps twice, But instead of getting an email saying Part 2 was completed, a couple days later I got an email saying Part 1 was ready for me. Even though I completed Part 1 previously and got an email saying I had completed it.

    • BarretBlake

      In reply to BarretBlake:
      Is someone actually monitoring this forum? I still have not gotten acknowledgement that Part 2 was completed nor the link to Part 3. I have gone through the steps 2 more times. I know that I have not missed any steps and it is actually pulling the Now and Forecast data for my location. Also double checked my ID is in the links being called.

  101. LouS

    After multiple tries I finally have a VS2017 installation with all of the required elements installed without error.

    However when I attempt to create the project I get the error below. Spent a lot of time to get this far, frustrated that I still can't get started. Guess this is why I've been a desktop developer for so many years - it just works out of the box. But I need to grasp new technologies, so any help you can provide would be greatly appreciated!



    Package Installation Error.

    Could not add all required packages to the project. The following packages failed to install from 'C;program files (x86)Microsoft SDKsNuGetPackages':

    Microsoft.NETCore.UniversalWindowsPlatform.5.1.0 : Package restore failed. Rolling back package changes for 'App1.UWP'

    • Codesmith

      In reply to LouS:

      My guess is there is an issue with the UWP workload. If you go to CoolBreeze (Universal Windows) > project.json do you have the following package listed in your dependencies node:

      "Microsoft.NETCore.UniversalWindowsPlatform": "5.1.0"? If not, add it, and you should be good to go!

      • LouS

        In reply to Codesmith

        After the update from earlier this week I was able to create and get the project built.  However I don't see any android devices when I have the Andriod project selected as default as shown in the document.   I have EVERYTHING installed for Xamarin and UWP according to the installer.    Selecting one of the options I do get (Microsoft Arm, Microsoft tablet,... ) nothing ever appears.

        I'm not a noob, I've been writing desktop apps in VS since VS2005.    But this sure has been frustrating....

  102. Trickyd

    Part 2 runs fine on Android (I have the tool bar button for forecast) , but running Windows Local Machine , I don't see a toolbar item for forecast, have tried rebuild all and deployed multiple times. As a workaround I added a local:ForecastPage entry to the TabbedPage.Children section of StartPage.xaml and that allows the forecast function to work on Windows and for Android/iOS they have both a tab and a toolbar button.

    • siko

      In reply to Trickyd:

      I found an answer to a the same question in the xamarin forums...

      Turns out you need to update your nuget packages on the solution. Especially xamarin.forms needs to be above 2.2.

  103. siko

    Ok, I'm ready (for 24 hours now), for step 2!

  104. BarryWallis

    On my first Deploy in Part 2 Step 19 I get the following errors:

    Missing partial modifier on declaration of type 'LocationPage'; another partial declaration of this type exists LocationPage.cs

    'Plugin' does not exist in the current context (I get this one in every place Plugin.* is used)

    Type 'LocationPage' already defines a member called '.ctor' with the same parameter types LocationPage.xaml

    Any help?

    • Codesmith

      In reply to BarryWallis:

      I would say something definitely got created wrong or a step was missed. If it were me I would just remove the entire thing and start over...as there is no telling what was missed. It's actually pretty quick just to get back where you were.

      • BarryWallis

        In reply to Codesmith:

        I got part 2 working. I undid everything including uninstalling and reinstalling Visual Studio. I found that when I added Xam.Plugin.Geolocator it failed (I probably didn't notice the first time). I ran Visual Studio as Administrator and was able to install Xam.Plugin.Geolocator successfully. I restarted Visual Studio with no privileges and was able to successfully deploy and run the initial portion of part 2.

      • BarryWallis

        In reply to Codesmith: I thought the same thing and restored back to the end of Step 1. Ended up with the same problem. I will now go back to ground zero and try again.

        Thanks for helping.

  105. Dan Hartwigsen

    I'm stuck at installing VS2017.  There is mention of Hyper-V in this thread, didn't see that in any pre-requirements from this challenge or VS.  I think I had VS installed at first, but adding the emulator components seems to be killing it.  I've deselected the W10 Mobile emulator, just checked Android and VS re-install failed again.  And I don't have a Mac so iOS isn't an option.  So am I out of the contest because I only have Win10 Home edition, which doesn't support the VM?  Thanks.

    • Codesmith

      In reply to Dan Hartwigsen:

      Is the a reason you can't just run the Challenge on Windows (Local Machine) as long as you follow the steps for Visual Studio Mobile Center integration for iOS and Android you can still complete the Challenge.

  106. KrisHermans

    Quick Tip: running the Android version on the Visual Studio emulator required me to configure the Hyper-V VM as explained by this gentleman. So not only is it required to use "Fast Deployment" in the Anrdoid settings, but you also have to enable a compatibility setting in Hyper-V manager > CPU.

  107. Jiayanxiang

    Just starting with the setup and it says under Individual components, I need to check Visual Studio Emulator for Android and Windows 10 Mobile Emulator (Anniversary Edition), but I don't even see these two options.  All I got is Google Android Emulator Level 23 and Intel Hardware Accelerated Execution Manager.

    Any idea why is that?  Thanks.

  108. leonzandman

    I'm currently working on Part 2 and I noticed that the URL for the weather API that gets constructed in GetCurrentConditionsAsync() is invalid on my machine. The longitude and latitude are of type 'double' and get converted into a string that contains a comma instead of a dot as a decimal separator. So the app crashes. Classic programming error, caused by the fact that my system is set to my (Dutch) region. I've fixed it using the following code:

           public async static Task<WeatherInformation> GetCurrentConditionsAsync(double latitude, double longitude)


               var lat = latitude.ToString(CultureInfo.InvariantCulture);

               var lon = longitude.ToString(CultureInfo.InvariantCulture);

               string url = $"http://traininglabservices.azurewebsites.net/api/weather/current?latitude={lat}&longitude={lon}&registrationCode={App.RegistrationCode}";

               HttpClient client = new HttpClient();

               var response = await client.GetStringAsync(url);

               var result = Newtonsoft.Json.JsonConvert.DeserializeObject<WeatherInformation>(response);

               return result;


    • Codesmith

      In reply to leonzandman:

      BTW, I went ahead and updated the back end so no one else will have to get blocked. Thanks for motivating me to get it covered. :)

    • Codesmith

      In reply to leonzandman:

      Yeah, I figured someone would eventually run into this, and I know better, but was secretly just "hoping against hope" since I couldn't go out and update the lab. I actually do a simple ToString("R") on the backend to handle it just in case, but that doesn't stop the double from casting as culture-specific and crashing before it even hits the service. #BlameMe

  109. KrisHermans

    I've managed to complete Part 2 of the challenge: everything runs fine on emulators (Android, UWP and iOS). However, if I deploy to my Android phone (Motorola 4G Plus, Nougat) or Google Nexus 7 tablet (Marshmellow), the app starts, but when it tries to access the real location an "unhandled exception" is raised. It seams like this line is the culprit:

    this.Location = await Helpers.LocationHelper.GetCurrentLocationAsync() in RefreshCurrentConditionsAsync

    any advice? Thanks!

    • jeffpro

      In reply to KrisHermans: Can you double-check that you modified the manifest as spelled out in Exercise 1, Step 6?

    • Codesmith

      In reply to KrisHermans:

      If you are fine in Emulators but not your actual device, you may want to uninstall it on the device, restart your device, and run it again. Also make sure in Settings > Location on your device you aren't blocking anything.

    • RamenJunkie

      In reply to KrisHermans:

      I was wondering if you (or anyone) figure this out. It seems like the emulator isn't getting location data. I have location enabled on the PC and the emulator, though the Emulator doesn't show up in the list of programs with access to location data on the local PC. Within the emulator it also says "no apps ahve requested location data". There seems to be a place in the emulator menu to send "fake" location data but it doesn't seem to work. I'm also going to test out the apk on my actual android device (Kindle) but at the moment the battery is dead.

    • RamenJunkie

      In reply to KrisHermans:

      Ok, I did a bunch so I don't know the exact steps but basically, after a bunch of investigating, i installed the emulator files for Android 7.0, then went in and created an emulator profile that used the 7.0 data. This seemed to fix my problem of getting Unhandled Exception from the real location weather.

  110. jrswarr

    OK - I am hoping I just got this email in error - whose subject title is "James, Step 1 is waiting for you. Start the Xamarin Challenge." - I worry because the last email i got  on this topic was titled "James, great job! You have finished the Xamarin Challenge!" HMMMM.

    I don't have a Mac - so I can't speak to running this in IOS - but I found the Android emulation to be very useable. I was totally disappointed with Windows Mobile emulation. Nothing seemed to fit in the screen size regardless of device selected - and I couldn't figure out how to get rid of intrusive diagnostic information off of the screen.

    • Glyn

      In reply to jrswarr:

      You are not alone :-)

      I completed the Challenge successfully on 26th March and was also invited to begin the Challenge today!

      Young people today... etc...

    • Codesmith

      In reply to jrswarr:

      I'm actually surpised by this, for me, personally the both Android and Windows emulators are lightning fast...

    • Tina

      In reply to jrswarr:

      Hi jrswarr,

      We have just sent an email out to people who registered but never started Step 1 to encourage them to start the challenge.

      We have a situation that may have swept you and others up in this email batch, so please don't panic. We do have a data lag between our marketing database and the challenge database. Because of this lag, some participants who have finished Step 1, 2 and 3 may have inadvertently been part of this email send.

      If you want me to check your progress, please email me at [email protected] and I am happy to make sure you are marked as completed. Please send me your Challenge code in the email.

      Thanks for your understanding.

    • lwetzel

      In reply to jrswarr:

      Got it also and just figured it was a mistake.

  111. barry505

    Who'd have thought the biggest challenge would be just to get Visual Studio to work. I've never seen such a buggy mess! I've encountered just about every error or warning listed in this post. (By the way, some of them might just be warnings, but it still won't compile or deploy.) I've tried it on 2 different computers, one with a fresh install of Windows; same problems.

    To be fair to us, I think you should pick the contest winners from all who registered, not just the ones who completed the challenge.

    • lvthunder

      In reply to barry505:

      I don't think that would be fair. Anyone can register for something. Not everyone would wait 3 days between the three different parts. Yeah a good part of the challenge is getting VS especially the Android emulators to run right, but it is called a challenge for a reason. I actually expected they were going to make us write the code ourselves.

      • barry505

        In reply to lvthunder: The Xamarin Challenge is kind of a joke. If you can read directions, it should work. You're not required to write any code. But when the platform we have to try to use is as broken as VS2017 w/Xamarin, it really isn't fair. I'd be interested in what percentage of participants actually got to the end of the challenge with no problems.

        • lvthunder

          In reply to barry505:

          I only had a small issue with the Android emulator. I had no problems with the UWP or the iOS emulators. Once I got past that I had no other issues. I've had these types of issues with Eclipse, VS, and XCode so stuff like this isn't unique to VS.

          I just think you need to work through the issues and complete the challenge instead of crying it's not fair.

          • Codesmith

            In reply to lvthunder:

            +1. All developers have challenges with environments and tools all day long. It's part of the job. If one of the main things we learn from the challenge is how to better setup our environments, then it's a bonus! :)

  112. lwetzel

    Went back through the Challenge from start to finish.  Being very careful. Trouble shooting when it didn't give the results expected.  Well now it gives me a greyed out "Submit my solution" button. Have contacted Xamarin Callenge Help Desk and they are looking into it.

    • Codesmith

      In reply to lwetzel:

      This is always related to the Visual Studio Mobile Center Installation ID not being set. Are you certain you have all the VSMC steps completed? This is where I would check, as that's the only way the button gets disabled, as it assumes you haven't finished those steps.

      • lwetzel

        In reply to lwetzel:

        Part 3 Exercise 1 the very last line says this "You have now registered the Android and iOS versions of the app with Visual Studio Mobile Center. You can't register the Windows version just yet, but Windows support is coming soon." Now I wonder if that is why they showed it being submitted in the android emulator.  That was what I finally did and got it in. 

      • lwetzel

        In reply to Codesmith:

        I am not sure what the problems were.  I did get it to work in the android emulator and submit and it said it was excepted.  They informed me today that it did.  But still not in the Local Device version.  Will look at your suggestion.  At least I am in for the drawing though I have a bad track record in winning.