Task return value, without Task<T> (async/await pattern)

asynchronous, c#, multithreading

Solution

You can't.

The entire point of `async` is to run code asynchronously. So the code returns a promise of a future `string` value, represented in .NET as `Task<string>`.

Think about it this way: if your code calls `public string GetSomeValue()`, then by the time the method returns, you already have a `string`. This is synchronous, by definition.

In your example, you have "heavy" work which I interpret to mean "CPU-bound". In that case, just do the work synchronously:

public string DoSomeHeavyWork()
{
  // do some long working progress and return a string
  return "Hello World!";
}

In general, APIs should not "lie"; if they are synchronous, then they should have a synchronous (non-`Task`-returning) signature.

Edit: As per your comment, the "heavy" work is a WCF call, which is I/O-bound, not CPU-bound.

In that case, the work is naturally asynchronous. Use asynchronous WCF methods (not `Task.Run`), and allow the asynchrony to grow through your codebase:

public async Task<string> GetSomeValueAsync()
{
  //directly return the value of the Method 'DoSomeHeavyWork'...
  var t = DoSomeHeavyWorkAsync();
  return await t;
}

public async Task<string> DoSomeHeavyWorkAsync()
{
  // Call asynchronous WCF client.
  await ...;
  return "Hello World!";
}

Problem

I would like to write the following: ``` public string GetSomeValue() { //directly return the value of the Method 'DoSomeHeavyWork'... var t = DoSomeHeavyWork(); return t.Result; } public Task<string> DoSomeHeavyWork() { return Task.Run(() => { // do some long working progress and return a string return "Hello World!"; }); } ``` As you can see to return the result from the `DoSomeHeavyWork()` I have used the Task.Result property, which works okay, but according to researches this will block the Thread. I would like to use the async/await pattern for this but cant seem to find how to do this. If I did the same with async/await with my current knowledge I will always end up with this: ``` public async Task<string> GetSomeValue() { //directly return the value of the Method 'DoSomeHeavyWork'... var t = DoSomeHeavyWork(); return await t; } public Task<string> DoSomeHeavyWork() { return Task.Run(() => { // do some long working progress and return a string return "Hello World!"; }); } ``` This solution doesnt quite fit my needs because I want to return ONLY the string and not a `Task<string>`, how can this be achieved with async/await?

Original source