How do you center your main window in WPF?

Question

I have a WPF application and I need to know how to center the wain window programatically (not in XAML).

I need to be able to do this both at startup and in response

Answer 1

What I am using in my app, it is working for multiple displays and for different DPI setting

    //center a window on chosen screen
    public static void CenterWindow(Window w, System.Windows.Forms.Screen screen = null)
    {
        if(screen == null)
            screen = System.Windows.Forms.Screen.PrimaryScreen;

        int screenW = screen.Bounds.Width;
        int screenH = screen.Bounds.Height;
        int screenTop = screen.Bounds.Top;
        int screenLeft = screen.Bounds.Left;

        w.Left = PixelsToPoints((int)(screenLeft + (screenW - PointsToPixels(w.Width, "X")) / 2), "X");
        w.Top = PixelsToPoints((int)(screenTop + (screenH - PointsToPixels(w.Height, "Y")) / 2), "Y");
    }

    public static double PixelsToPoints(int pixels, string direction)
    {
        if (direction == "X")
        {
            return pixels * SystemParameters.WorkArea.Width / System.Windows.Forms.Screen.PrimaryScreen.WorkingArea.Width;
        }
        else
        {
            return pixels * SystemParameters.WorkArea.Height / System.Windows.Forms.Screen.PrimaryScreen.WorkingArea.Height;
        }
    }

    public static double PointsToPixels(double wpfPoints, string direction)
    {
        if (direction == "X")
        {
            return wpfPoints * System.Windows.Forms.Screen.PrimaryScreen.WorkingArea.Width / SystemParameters.WorkArea.Width;
        }
        else
        {
            return wpfPoints * System.Windows.Forms.Screen.PrimaryScreen.WorkingArea.Height / SystemParameters.WorkArea.Height;
        }
    }