1. How to Use Dispatcher in WPF to Build Responsive Applications

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3. http://www.beingdeveloper.com/use-dispatcher-in-wpf-to-build-responsive-applications/

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2. private void Button_Click_2(object sender, RoutedEventArgs e)
3. {
4.     // Start a stop watch to count the execution time
5.     var stopWatch = Stopwatch.StartNew();
6.     lstItems.Items.Clear();
8.     // Define and start a new thread to add 20000 items to the list box
9.     ThreadStart job = new ThreadStart(() =>
10.     {
12.         for (int i = 0; i < 20000; i++)
13.         {
14.             // The new thread puts UI operations in the dispatching queue
15.             Dispatcher.Invoke(DispatcherPriority.Normal, new Action(() =>
16.             {
17.                 lstItems.Items.Add("Stock Item " + i);
18.             }));
19.         }
21.         stopWatch.Stop();
23.         //! I cannot access WPF objects that is on the UI thread like this:
24.         // lblTime.Content = "Finished in " + (double)stopWatch.ElapsedMilliseconds / 1000 + " seconds";
26.         // I have to use the Dispatcher class as a mediator to queue the UI operation
27.         Dispatcher.Invoke(DispatcherPriority.Normal, new Action(() =>
28.         {
29.             lblTime.Content = "Finished in " + (double)stopWatch.ElapsedMilliseconds / 1000 + " seconds";
30.         }));
32.     });
34.     Thread thread = new Thread(job);
35.     thread.Start();
36. }