Window Closing and Closed event
<Window x:Class="ApplicationShutdownSample.ChildWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="Application Shutdown Sample" Closing="ChildWindow_Closing" Closed="ChildWindow_Closed"> <Grid> </Grid> </Window> //File:Window.xaml.vb Imports System Imports System.ComponentModel Imports System.Windows Namespace ApplicationShutdownSample Public Partial Class ChildWindow Inherits Window Public Sub New() InitializeComponent() End Sub Private Sub ChildWindow_Closing(sender As Object, e As CancelEventArgs) Console.WriteLine("Closing") Dim result As MessageBoxResult = MessageBox.Show("Allow Shutdown?", "Application Shutdown Sample", MessageBoxButton.YesNo, MessageBoxImage.Question) e.Cancel = (result = MessageBoxResult.No) End Sub Private Sub ChildWindow_Closed(sender As Object, e As EventArgs) Console.WriteLine("Closed") End Sub End Class End Namespace