BlockThread.xaml
<Window x:Class="WPFThreading.BlockThread" 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" > <Window.Resources> <Style TargetType="{x:Type Button}"> <Setter Property="Height" Value="20" /> <Setter Property="Background" Value="Beige"/> <Setter Property="Margin" Value="2" /> </Style> <Style TargetType="{x:Type Label}"> <Setter Property="FontWeight" Value="Bold" /> <Setter Property="Margin" Value="2" /> </Style> <Style TargetType="{x:Type TextBox}"> <Setter Property="Margin" Value="2" /> </Style> </Window.Resources> <Border Width="200" Height="225" BorderBrush="Black" BorderThickness="1" Margin="4"> <StackPanel> <Label>Simulate Long-Running Process</Label> <Button Name="button1" Click="button1_click">Go to sleep</Button> <Label>Will I respond?</Label> <Button Name="button2" Click="button2_click">Try Me</Button> <Label>Output Messages</Label> <TextBox Name="textbox1"/> <Label/> <StackPanel Orientation="Horizontal"> <Label>UI thread:</Label> <Label Name="UIThreadLabel"></Label> </StackPanel> <StackPanel Orientation="Horizontal"> <Label>BG thread:</Label> <Label Name="BackgroundThreadLabel"></Label> </StackPanel> </StackPanel> </Border> </Window> //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"; } } }