This blog is just for sample code keeping. // UserControl1.xaml <UserControl x:Class=”WpfApp1.UserControl1″              xmlns=”http://schemas.microsoft.com/winfx/2006/xaml/presentation”              xmlns:x=”http://schemas.microsoft.com/winfx/2006/xaml”              xmlns:mc=”http://schemas.openxmlformats.org/markup-compatibility/2006″              xmlns:d=”http://schemas.microsoft.com/expression/blend/2008″              xmlns:local=”clr-namespace:WpfApp1″              mc:Ignorable=”d” Background=”Red” Height=”186.646″ Width=”411.693″>     <Grid>         <Button Content=”Button” HorizontalAlignment=”Left” Margin=”80,72,0,0″ VerticalAlignment=”Top” Width=”75″ Click=”Button_Click”/>     </Grid> </UserControl> // UserControl1.xaml.cs namespace WpfApp1 {     /// <summary>     /// Interaction logic for UserControl1.xaml     /// </summary>     public partial class UserControl1 : UserControl     {         public event EventHandler MyButtonClick;         public UserControl1()         {             InitializeComponent();         }         private void Button_Click(object sender, RoutedEventArgs e)         {             this.MyButtonClick(this, new EventArgs());         }     } } //…