MVC4 + async/await + return response before action completes

Question

In my MVC4 app I need to add a controller for uploading and processing large files. Immediately after the file is uploaded I need to start async processing of that file and

Answer 1

You have an error in your code. You must await the call to TestAsync in your action. If you don't, it simply returns a "Task" object without running anything.

public async Task Test()
{
    await TestAsync();
    return View("Test");
}

and the correct way to sleep in an async method is to call

await Task.Delay(10000);

You have to change the signature of TestAsync: you should not mark a method async if it returns void. It must return Task instead. Returning void is reserved for compatibility with .net events.

public async Task TestAsync()
{
    await LongRunning();
}

The method body is the same.