How to use Application.Exit Event in WPF?

Question

I need to delete some certain files, then user closes program in WPF. So I tried MDSN code from here http://msdn.microsoft.com/en-us/library/system.windows.application.exit.

Answer 1

If you don't like adding Exit event to XAML, you could try this alternative.

Add following method to your App.xaml.cs:

protected override void OnExit(ExitEventArgs e)
{
    base.OnExit(e);
    // Your code here
}

Answer 2

you should add app_exit in your xaml code

 <Application x:Class="CSharp.App"
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  StartupUri="MainWindow.xaml" 
  ShutdownMode="OnExplicitShutdown"
  Exit="App_Exit"
    >
</Application>

you can just hook the event Closing on your main window like this -

 <Window Closing="Window_Closing">

And in your event do all the work you need

    private void Window_Closing(object sender, CancelEventArgs e)
{
     MessageBox.Show("File deleted");
    var systemPath = System.Environment.GetFolderPath(
                              Environment.SpecialFolder.CommonApplicationData);

            var _directoryName1 = Path.Combine(systemPath, "RadiolocationQ");
            var temp_file = Path.Combine(_directoryName1, "temp.ini");

            if (File.Exists(temp1_file))
            {
                File.Delete(temp1_file);
            }
}

Answer 3

If you want to follow MVVM principle you can use System.Windows.Interactivity.WPF.

MainWindow.xaml

<Window x:Class="Endonext.View.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006">

<i:Interaction.Triggers>
    <i:EventTrigger EventName="Closing">
        <i:InvokeCommandAction Command="{Binding WindowClosingCommand, Mode=OneTime}" />
    </i:EventTrigger>
</i:Interaction.Triggers>

MainWindowViewModel.cs

public class MainWindowViewModel 
{
    ICommand WindowClosingCommand => new RelayCommand(arg => this.WindowClosing());

    private void WindowClosing()
    {
      // do what you want.
    }
}

This approach is more testable. Have a nice day.

Answer 4

1. Make sure that the namespace (MyApp) matches "x:Class=MyApp..."
2. Under properties for <Application></Application>, double click on the textbox next to 'Exit'.
3. If you get "Unable to add event handler" then Rebuilding the project fixed it for me.

XAML

<Application x:Class="MyApp.App"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         StartupUri="MainWindow.xaml"
         Exit="Application_Exit"
>

Code behind

using System.Windows;

namespace MyApp
{ 
   public partial class App : Application
   {
     private void Application_Exit(object sender, ExitEventArgs e)
     {
         //your code
     }
  }
}

Answer 5

It's quite simple:

Add "Exit" property to the application tag

<Application x:Class="WpfApplication4.App"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             StartupUri="MainWindow.xaml"
             Exit="Application_Exit">
</Application>

and handle it in the "code behind"

private void Application_Exit(object sender, ExitEventArgs e)
{
    // Perform tasks at application exit
}

The Exit event is fired when the application is shutting down or the Windows session is ending. It is fired after the SessionEnding event. You cannot cancel the Exit event.