Question

how to catch an unhandled exception? if all my code wrapped in a try catch?
but an exception occurs all the same, and the application crashes … Maybe there is some general advice?

use:

        try
            {
             ...my code
            }
        catch (Exception ex)
            {
                MessageBox.Show(ex.Message.ToString(),"Error!",MessageBoxButton.OK);
            }

Sample code is not present, because there is a big code and done many things … and it looks like somewhere an error occurs, but where it is try-catch does not show, and the application just closes …

add:

var errorw = MessageBox.Show(e.ExceptionObject.ToString(), "error", MessageBoxButton.OK); e.Handled = true; 

And the message: The parameter is incorrect.

Just as we now understand where and what parameter has given is not true? By the way forgot to write that the error occurs when you press Back, when you return to the previous page of the application.

Answer 1

would you try like this

      // Code to execute on Unhandled Exceptions
private void Application_UnhandledException(object sender,ApplicationUnhandledExceptionEventArgs e)
{
    if (e.ExceptionObject is QuitException)
        return;

    if (System.Diagnostics.Debugger.IsAttached)
    {
        // An unhandled exception has occurred; break into the debugger
        System.Diagnostics.Debugger.Break();
    }

    //MessageBox.Show(e.ExceptionObject.ToString(), "Unexpected error", MessageBoxButton.OK);

    var errorWin = new ErrorWindow(e.ExceptionObject, "An unexpected error has occurred. Please click Send to report the error details.")
                       {Title = "Unexpected Error"};
    errorWin.Show();
    //((PhoneApplicationFrame) RootVisual).Source = new Uri("/Views/ErrorWindow.xaml", UriKind.Relative);

    e.Handled = true;
}

private class QuitException : Exception { }

public static void Quit()
{
    throw new QuitException();
}