Exceptions debugging with async and UWP

Question

I'm working on the UWP application. And I'm using async/await a lot. Always when an exception occurs in my code the debugger set break in App.g.i.cs

#if DEBUG && !DISABLE_XAML_GENERATED_BREAK_ON_UNHANDLED_EXCEPTION
            UnhandledException += (sender, e) =>
            {
                if (global::System.Diagnostics.Debugger.IsAttached) global::System.Diagnostics.Debugger.Break();
            };
#endif

But I want to see the line when the exception occured. How to achieve that behavior ?

Answer 1

Add the following method to your App class:

private static void UnhandledError(object sender, UnhandledErrorDetectedEventArgs eventArgs)
{
    try
    {
        // A breakpoint here is generally uninformative
        eventArgs.UnhandledError.Propagate();
    }
    catch (Exception e)
    {
        // Set a breakpoint here:
        Debug.WriteLine("Error: {0}", e);
        throw;
    }
}

In your App constructor:

public UnitTestApp()
{
    CoreApplication.UnhandledErrorDetected += UnhandledError;

    // ...and any other initialization.
    // The InitializeComponent call just sets up error handlers,
    // and you can probably do without in the case of the App class.

    // This can be useful for debugging XAML:
    DebugSettings.IsBindingTracingEnabled = true;
    DebugSettings.BindingFailed +=
        (sender, args) => Debug.WriteLine(args.Message);

}

There are still cases where you don't get a good stack trace, but this is often helpful.

Another approach is to break when an exception is thrown (via Debug, Windows, Exception Settings).