Async, Await, Tasks, and Returns...

[JaedenRuiner]

Okay,

I am missing something that my old school brain of handing threads, background workers, and the like is just not grasping.

• async void X() {}
  this is supposed to be for event handlers only in order to "await" a Task in a multi-threaded environment
• async Task X() {}
  this is for asynchronous methods that don't have a return value
• async Task<T> X() {}
  this is for asynchronous methods that have a return value
• Task X() and Task<T> X()
  these are methods that can be called with "await", but can't "await" themselves.

Question:

I have a method that i want to run asynchronously, but Visual Studio complains every which way i do it.

async void button1_click(sender, e)
{
this.MyData = await this.LoadData();
}

//This complains about the return type not being a "Task<MyDataObject>", but i can't "create" a "Task<>"
private Task<MyDataObject> LoadData()
{
MyDataObject mdo = new MyDataObject();
this.LoadFromDb(mdo);
return mdo;
}

//This complains that LoadData doesn't "await" anything, so remove the async, but it works
private async Task<MyDataObject> LoadData()
{
MyDataObject mdo = new MyDataObject();
this.LoadFromDb(mdo);
return mdo;
}


That's my issue, straight forward. I understand threads, the CancelationTokens, synchronizing for report progress feed back, all that jazz.

I mean, is it the standard approach to do this:

private Task<MyDataObject> LoadData()
{
MyDataObject mdo = new MyDataObject();
this.LoadFromDb(mdo);
return Task.FromResult(mdo);
}

Are we only supposed to use the "async" if we're going to "await" in the method, and thus if that method does not need to await, we use the "FromResult" statement on Task?


Thanks

Jaeden "Sifo Dyas" al'Raec Ruiner




"Never Trust a computer. Your brain is smarter than any micro-chip."
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