The UWP Notepad Project (Redux): Auto Save (Premium)

Today, we’ll implement .NETpad’s Auto Save functionality, which will work nearly identically to the way we did it previously in Windows Presentation Foundation (WPF).

To get started, we need to add a DispatchTimer to our project using code. (You may recall that in Windows Forms, we could drag a Timer object in from the toolbox, but with UWP and WPF, we need to do this manually.)  So open up MainPage.xaml.cs and scroll up to the top and locate the MainPage class definition. There, you will find a variety of what I call global variables, broken into groups like “For font settings,” “For other (non-font) settings” and so on. Below the last group (“For Find and Replace”) open up some space and add the following code:
// For Auto Save
readonly DispatcherTimer Timer1 = new DispatcherTimer();
Now, locate ReadSettings(). At the bottom of the main if clause (which fires when there are saved savings to use), you’ll find an “Auto Save” section that looks like so:
// Auto Save
if (myAutoSave == true)
    AutoSaveButton.Content = "Auto Save: On";
else
    AutoSaveButton.Content = "Auto Save: Off";
We need to edit this code to specify the timer’s Interval property, which is the frequency at which its Tick() method will fire. And we need to specify a method that will handle that Tick event. Then, we need to start the timer if the myAutoSave variable (and thus the MyAutoSave setting) are true, or stop it if it is not.

The revised code will look like so:
// Auto Save
Timer1.Interval = TimeSpan.FromSeconds(3);
Timer1.Tick += Timer1_Tick;
if (myAutoSave == true)
{
    AutoSaveButton.Content = "Auto Save: On";
    Timer1.Start();
}
else
{
    AutoSaveButton.Content = "Auto Save: Off";
    Timer1.Stop();
}
Two notes here.

First, we’re setting the timer interval to 3 seconds now for testing purposes: It would be tedious to wait 30 seconds to see whether our code works. When we’re sure that everything is working properly, we will change that to 30, for 30 seconds.

Second, the Timer1_Tick bit will have a red squiggly under it because that method doesn’t yet exist. So let’s add that next: Scroll down to the bottom of the MainPage class definition and add the following empty event handler below whatever is currently the last method there (it’s ZoomInButton_Click() on my PC).
private void Timer1_Tick(object sender, object e)
{
    //
}
We’ll add some code in there later, but that is enough to clear up the error we were seeing.

Next, locate AutoSaveSwitch_Toggled(). This method fires when the user makes a change to the Auto Save setting in the Settings pane. Currently it looks like this:
private void AutoSaveSwitch_Toggled(object sender, RoutedEventArgs e)
{
    if (AutoSaveSwitch.IsOn == true)
        AutoSaveButton.Content = "Auto Save: On";
    else
        AutoSaveButton.Content = "Auto Save: Off";
    SaveOtherSettings();
}
As...