TaskCanceledException when calling Task.Delay with a CancellationToken in an keyboard event

If you add ContinueWith() with an empty action, the exception isn't thrown. The exception is caught and passed to the task.Exception property in the ContinueWith(). But It saves you from writing a try/catch that's uglify your code.

await Task.Delay(500, cancellationToken.Token).ContinueWith(tsk => { });

That's to be expected. When you cancel the old Delay, it will raise an exception; that's how cancellation works. You can put a simple try/catch around the Delay to catch the expected exception.

Note that if you want to do time-based logic like this, Rx is a more natural fit than async.

Curiously, the cancellation exception seems to only be thrown when the cancellation token is on Task.Delay. Put the token on the ContinueWith and no cancel exception is thrown:

Task.Delay(500).ContinueWith(tsk => {
   //code to run after the delay goes here
}, cancellationToken.Token);

You can just chain on yet another .ContinueWith() if you really want to catch any cancellation exception - it'll be passed into there.