WPF Close button not working when in Grid

When I place Button in grid and add to is's click action:

this.Close();

It's not working. I want to be able to ask user before exit so I w开发者_运维知识库ant to use Close(). I don't want to use Application.Shutdown(); How to solve it.

Just tested it and it works fine! I created a new WPF application and a basic window:

<Window x:Class="WpfApplication1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <Button Content="Close" x:Name="closeButton" Click="closeButton_Click" />
    </Grid>
</Window>

and then added the following to the code-behind

private void closeButton_Click(object sender, RoutedEventArgs e)
{
        if (MessageBox.Show("Are you sure?", "Application", MessageBoxButton.YesNo) == MessageBoxResult.Yes)
        {
            this.Close();
        }
}

And it works 100%... Can you post more code to see if something else is wrong? What .NET version are you using, etc...