Hands-On Mobile Development with .NET Core

Asynchronous event handling

As we mentioned earlier, if the chain of calls demand asynchronous execution, the async chain should in fact be propagated all the way to the top of the call hierarchy. Deviating from this setup may cause threading issues, race conditions, and possibly deadlocks. Nevertheless, it is also important that the methods should not deviate from the async Task declaration, ensuring that the async stack and generated results and errors are preserved.

Event handlers with asynchronous code are a good example of where we would not have much to say about the signature of a method. For instance, let's take a look at the button click handler that should execute an awaitable method:

public async void OnSubmitButtonTapped(object ...