How to hide part of the window on the second monitor(screen)

Question

The window goes to a second monitor, but there should not be visible. How to hide the area?

Example image

Your only option would be to resize the window to fit to the screen, you can't make part of the window invisible. Why would you even want to do it? — Glen Thomas, Apr 01 '16 at 21:14
I created an application in form similar to the Action Center in Windows 10. But they have done it? — user3328301, Apr 01 '16 at 23:46

score 1 · Accepted Answer · answered Apr 01 '16 at 23:05

It's not clear why you need this, but it can be achieved with some effort. The trick is OpacityMask property, which allows to make elements partially transparent. Some code to give you rough idea:

public MainWindow() {
        InitializeComponent();            
        this.WindowStyle = WindowStyle.None; // required for AllowsTransparency
        this.AllowsTransparency = true; // allow window to be transparent            
        var group = new DrawingGroup();
        // make first 100x1000 part of window transparent
        group.Children.Add(new GeometryDrawing() {Brush = Brushes.Transparent, Geometry = new RectangleGeometry(new Rect(0, 0, 100, 1000))});
        // make the rest part white or whatever color you use
        group.Children.Add(new GeometryDrawing() {Brush = Brushes.White, Geometry = new RectangleGeometry(new Rect(100, 0, 1000, 1000))});
        this.OpacityMask = new DrawingBrush(group) {
            Stretch = Stretch.None,
            AlignmentX = AlignmentX.Left,
            AlignmentY = AlignmentY.Top
        };
    }

Thank you. I am creating a menu information that pops up when click on the icon in the system tray as Action Center in Windows 10. Your method is right for me, but the problem arose in the blur on the background of window — user3328301, Apr 01 '16 at 23:38

How to hide part of the window on the second monitor(screen)

1 Answers1