Question

i have program like this

private void  do_my_method_click(object sender, RoutedEventArgs e)
{  
      //there are some variables and methods here

      //works fine
      ThreadPool.QueueUserWorkItem(Start_method);  

      // when added gives error this thread owned by other thread
      ThreadPool.QueueUserWorkItem(Start_method_2);
}

Start_method(object state)
{
}

Start_method_2(object state)
{
}

output of Start_method is used in Start_method_2 i dont know exactly where i am going wrong and i am a newbie for WPF and C#.

Answer 1

As @Tudor suggested, inside Start_method_2 you are modifying the GUI I think.

Use System.Threading.SynchronizationContext.Current if you are modifying something on the UI which works on the main thread. Here is an example:

var sync = System.Threading.SynchronizationContext.Current;

sync.Post(x => { 

    TextBlock1.Text = "Foo";

}, null);

This code is safe but it misses a lot (exception handling, etc.). Here is also another question for a similar issue which I suffered when I knew about threading a little:

Simple Async operation with Continuation scenario doesn't work on a WPF app