Exception handling for events

Question

I apologize if this is a simple question (my Google-Fu may be bad today).

Imagine this WinForms application, that has this type of design: Main application -> shows

Answer 1

Yes, the default handling of Application.ThreadException was a mistake. Unfortunately, it was a necessary mistake, needed to not immediately discourage and despair hundreds of thousands of programmers writing their first Windows Forms application.

The fix you are contemplating is not a fix, it has a lot of potential to make it worse. While a user clicking the Continue button on the exception dialog is a questionable outcome, swallowing exceptions in a global exception handler is much worse.

Yes, do write a replacement handler for ThreadException. Have it display the value of e.Exception.ToString() in a message box so the user has some idea what blew up. Then fire off an email or append to an error log so you know what went wrong. Then call Environment.FailFast() so no more damage can be done.

Do the same for AppDomain.CurrentDomain.UnhandledException. It won't get much of a workout.

Use the feedback to improve your code. You'll find out where validation is required. You can help the customer's IT staff diagnose trouble with their LAN and equipment. And you'll find the very few cases where your own try/catch blocks might be able to recover from the exception.