complete the branch

HandyControlDemo/UserControl/Controls/NotifyIconDemoCtl.xaml.cs

@@ -1,4 +1,6 @@
-namespace HandyControlDemo.UserControl
+using System.Windows;
+
+namespace HandyControlDemo.UserControl
 {
     public partial class NotifyIconDemoCtl
     {
@@ -6,5 +8,7 @@
         {
             InitializeComponent();
         }
+
+        private void ButtonPush_OnClick(object sender, RoutedEventArgs e) => NotifyIconContextContent.CloseContextControl();
     }
 }