ChaseLukeA/WPFGlobalExceptionHandlingNuget

For creating WPF Global Exception Handling NuGet package

Windows Presentation Foundation (WPF) Global Exception Handling

For handling exceptions in the App.xaml.cs file of any .NET Framework WPF Application.

About

This project was created with a desire to handle all exceptions (or unhandled exceptions if that's you're desire) at a global level in WPF applications

Usage

• Add WPFGlobalExceptionHandling to your list of references

• Add using WPFGlobalExceptionHandling; to the header of your App.xaml.cs file

• Add the interface IWPFGlobalExceptionHandler to the App.xaml.cs class

  • Example: public partial class App : Application, IWPFGlobalExceptionHandler { }

• Implement the two interface member methods that IWPFGlobalExceptionHandler interfaces

  • HandleException() handles "normal" unhandled exeptions that can be safely handled
    • Example:

         public void HandleException(Exception e)
     	{
     		// logs the exception, including inner exceptions
     		logger.Error(e);
    
     		// shows a message box with the root exception
     		MessageBox.Show(e.GetRootException().Message, "Uh-oh, something went wrong!", MessageBoxButton.OK, MessageBoxImage.Error);
     	}
    

  • HandleUnrecoverableException() handles "unrecoverable" unhandled exeptions and then closes the application
    • Example:

     	public void HandleUnrecoverableException(Exception e)
     	{
     		// logs the exception, including inner exceptions
     		logger.Fatal(e);
    
     		// shows a message box with the root exception
     		MessageBox.Show($"The application is now going to close.\n\n'{e.GetRootException().Message}'", "Unrecoverable Error!", MessageBoxButton.OK, MessageBoxImage.Error);
     	}
     ```
    

• In the App.xaml.cs constructor, add a call to this.UseGlobalExceptionHandling();

  • This uses the extension method in WPFGlobalExceptionHandling for Application classes interfacing IWPFGlobalExceptionHandler
  • Four different handlers are used to handle exceptions globally:
    1. AppDomain.CurrentDomain.UnhandledException handles non-UI thread exceptions thrown; the app terminates after unhandled exceptions are caught here
    2. app.DispatcherUnhandledException handles UI dispatcher thread exceptions thrown
    3. TaskScheduler.UnobservedTaskException handles domain-wide exceptions where a task scheduler is used for asynchronous operations
    4. DataBindingErrorHandler.ThrowExceptionsWithDataBindingErrors() allows DataBinding errors to throw exceptions, which are then caught by DispatcherUnhandledException

• Now any time an exception occurs at any level, on any thread, it will be caught at App level and handled in one of the two interface methods, HandleException() or HandleUnrecoverableException()