WPF C#

  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  Title="UI Thread Blocker" Height="275" Width="225"
  >
  
    
      
      
      
    
    
      
      
    
    
      
    
  

      BorderThickness="1" Margin="4">
    
      
      Go to sleep
      
      Try Me
      
      
      
      

      
        
        
      
    
  

//File:Window.xaml.cs
using System.Windows;
namespace WPFThreading
{
  public partial class BlockThread : System.Windows.Window
  {
    public BlockThread()
    {
      InitializeComponent();
      this.UIThreadLabel.Content = this.Dispatcher.Thread.ManagedThreadId;
      this.BackgroundThreadLabel.Content = "N/A";
    }
    private void button1_click(object sender, RoutedEventArgs e)
    {
      System.Threading.Thread.Sleep(5000);
      this.textbox1.Text = "Done Sleeping...";
    }
    private void button2_click(object sender, RoutedEventArgs e)
    {
      this.textbox1.Text = "Hello WPF";
    }
  }
}