How to create a task (TPL) running a STA thread?

Using Thread is pretty straightforward

 Thread thread = new Thread(MethodWhichRequiresSTA);
 thread.SetApartmentState(ApartmentState.STA);  

How to accomplish the same using Tasks in a WPF application? Here is some code:

Task.Factory.StartNew
  (
    () => 
    {return "some Text";}
  )
   .ContinueWith(r => AddControlsToGrid(r.Result));  

I'm getting an InvalidOperationException with

> The calling thread must be STA, because many UI components require this.

You can use the TaskScheduler.FromCurrentSynchronizationContext Method to get a TaskScheduler for the current synchronization context (which is the WPF dispatcher when you're running a WPF application).

Then use the ContinueWith overload that accepts a TaskScheduler:

var scheduler = TaskScheduler.FromCurrentSynchronizationContext();

Task.Factory.StartNew(...)
            .ContinueWith(r => AddControlsToGrid(r.Result), scheduler);

Dispatcher.Invoke could be a solution. e.g.

	private async Task<bool> MyActionAsync()
	{
		// await for something, then return true or false
	}
	private void StaContinuation(Task<bool> t)
	{
		myCheckBox.IsChecked = t.Result;
	}
	private void MyCaller()
	{
		MyActionAsync().ContinueWith((t) => Dispatcher.Invoke(() => StaContinuation(t)));
	}