How to use async/await with a library that uses an event-based asynchronous pattern?

Question

I use a library that has an asynchronous method called DoWork(...) that will raise a WorkDone event when the operation completes.

I would like to write a method that

Answer 1

You can use TaskCompletionSource:

public async Task<Result> SomeMethod()
{
   var result = new TaskCompletionSource<Result>();

   library.WorkDone += (data) =>
                                {
                                    result.SetResult(data);
                                };
   library.DoWork();

   return await result.Task;
}

Answer 2

I will build on ws0205's answer:

First, you indicate that you want your method "to be called with await". You achieve this by returning a Task.

I also think that it's better to make the following adjustments to ws0205's answer:

public Task<Result> SomeMethod() //no async, since we're not awaiting anything
{
   var result = new TaskCompletionSource<Result>();

   library.WorkDone += (data) =>
                                {
                                    result.TrySetResult(data); //just in case 
                                };
   library.DoWork();

   return result.Task; //no need to await - we're returning a Task - let the caller await (or not)
}