Xamarin.Forms - BeginInvokeOnMainThread for an async Action

Question

I am familiar with the rules about updating UI elements on the UI thread using the Device.BeginInvokeOnMainThread, however I have an operation that needs to be run on the UI

Answer 1

Since Xamarin.Forms 4.2 there is now a helper method to run tasks on the main thread and await them.

await Device.InvokeOnMainThreadAsync(SomeAsyncMethod);

Several overloads exist that should cover most scenarios:

System.Threading.Tasks.Task InvokeOnMainThreadAsync (System.Action action);
System.Threading.Tasks.Task InvokeOnMainThreadAsync (System.Func funcTask);
System.Threading.Tasks.Task InvokeOnMainThreadAsync (System.Func> funcTask);
System.Threading.Tasks.Task InvokeOnMainThreadAsync (System.Func func);

Related PR: https://github.com/xamarin/Xamarin.Forms/pull/5028

NOTE: the PR had some bug that was fixed in v4.2, so don't use this in v4.1.