The WPF Notepad Project: Select All, Time/Date, Go To, and Input Box (Premium)

In this installment, we’ll implement several more Edit menu items in the WPF version of .NETpad and create a custom Input Box.
Edit > Select All
Implementing Edit > Select All is as easy as was implementing Cut, Copy, and Paste. All we need to do is associate the SelectAllMenu menu item with the SelectAll command in MainWindow.xaml. So open up that file and add a Command property to i...