How to call asynchronous method from synchronous method in C#?

Question

I have a public async void Foo() method that I want to call from synchronous method. So far all I have seen from MSDN documentation is calling async methods via

Answer 1

You can call any asynchronous method from synchronous code, that is, until you need to await on them, in which case they have to be marked async too.

As a lot of people are suggesting here, you could call Wait() or Result on the resulting task in your synchronous method, but then you end up with a blocking call in that method, which sort of defeats the purpose of async.

I you really can't make your method async and you don't want to lock up the synchronous method, then you're going to have to use a callback method by passing it as parameter to the ContinueWith method on task.