I needed to brush up on event handling so I wrote this app. I based it Mosh's video on event handling. https://www.youtube.com/watch?v=jQgwEsJISy0
If you haven't checked out Mosh do yourself a favor - he has stuff on Pluralsight and Udemy and the Udemy classes are so cheap it's worth it to check out.
You can probably guess the theme of my exercise.