Question

So here is my code:

class Program
{
  static DispatchClass dc;

  [STAThread]
  static void Main(string[] args)
  {
    dc = new DispatchClass();

    Thread th = new Thread(AccessDC);
    th.Start();

    Console.ReadKey();
  }

  private delegate void AccessDCDelegate(object state);
  static private void AccessDC(object state)
  {
    if(dc.Dispatcher.CheckAccess())
      dc.Print("hello");
    else
      dc.Dispatcher.Invoke(new AccessDCDelegate(AccessDC));
  }
}

public class DispatchClass : DispatcherObject
{
  public void Print(string str)
  {  
    Console.WriteLine(str);
  }
}

Now…the output I would expect from this is for the created thread to check the dispatcher access, see that it is on a different thread and then invoke AccessDC(…) on the original thread which then checks and sees that it is on the correct thread and calls dc.Print(…).

What actually happens is it gets to CheckAccess() and correctly sees that it isn’t on the correct thread, then calls Invoke(…) and stops there.

Any insight into how Dispatchers work would be greatly appreciated.

Thanks.

Answer 1

The dispatcher requires a message pump, console apps do not have a message pump by default. Try running this as a GUI application instead – that will have a message pump.