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.aspx> this way:

this code located here `App.xml.cs`

```
public partial class App : Application
{
 void App_Exit(object sender, ExitEventArgs 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);
                }

    }

}

// App.xaml
<Application x:Class="ModernUIApp1.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.Resources>

```

First of all it doesn't delete files, secondly this program stays in the process after I pushed exit button( this is really strange). This code don't give any errors. And finally it doesn't show `MessageBox` So anything wrong here?

I think he just can`t find this function.