C# Await in a delegate call

Question

I have a function :

public async Task DoStuff()
{
    await DoSomethingAsync();
}

I need to call it from code running this:

list.ItemTapped += async (sender, e) =>
{
    file.WriteAllBytes(reportPdf, data, () => **await** file.DoStuff());
};

But the await is not allowed in the Action file.DoStuff called in the above???

Answer 1

While GazTheDestroyer's answer is correct, there's no reason for the lambda expression to be marked async and to use an await since file.DoStuff already returns a Task and fits the Func<Task> delegate:

list.ItemTapped += async (sender, e) =>
{
    file.WriteAllBytes(reportPdf, data, () => file.DoStuff());
};

It would also slightly improve performance since there's no reason to construct the state machine required for an async-await method/delegate.

Answer 2

Your second lambda is not marked async

 list.ItemTapped += async (sender, e) =>
 {
      file.WriteAllBytes(reportPdf, data, async () => await file.DoStuff());
 };

This depends on file.WriteAllBytes() allowing a Func<Task> to be passed in. An Action will not be enough.