How can I check if user DIDN'T click on any UI Elements? If he missed the click and simply clicked on the background

Question

So I modify some button's colors that I want to reset when the user clicks outside any of the buttons from the grid, but still clicks somewhere in the UserControl. I tried to add a MouseDown event to the background of the grid but it it not a valid event. Something like this

<Grid.Background>
        <ImageBrush
            Mouse.MouseDown="ImageBrush_MouseDown"
            ImageSource="/Res/maptest3.png"
            Stretch="None"
            />
 </Grid.Background>

Answer 1

<Window x:Class="MyApp.MainWindow" x:Name="windowClicked" //Add this to the xaml file

In the source code:

private void windowClicked_MouseDown(object sender, MouseButtonEventArgs e)
    {
        // or your what you want to do
        MessageBox.Show("Background Clicked"); 
    }