How to maximize a window in background?

Question

I need to maximize a window in background, meaning without activating (focusing) it. SetWindowPlacement function doesn\'t offer this.. Any ideas?

        WINDOWP         


        

Answer 1

Please use the below code at the time of windows load

    private void Form1_Load(object sender, EventArgs e)
    {
        this.WindowState = FormWindowState.Maximized;

    }

This will maximise your window

Answer 2

The best way I could find to do this was (VB sorry!);

longForeHWnd = GetForegroundWindow
Call ShowWindow(longBackHWnd, SW_SHOWMAXIMIZED)
SetForegroundWindow (longForeHWnd)

This is only a work-around because the Background Window is (briefly) activated and so gets promoted up the Z-Order

Answer 3

Try this using definitions from http://www.pinvoke.net:

WINDOWPLACEMENT placement;
if (GetWindowPlacement(hWnd, out placement))
{
    if ((GetWindowLong(hWnd, GWL_EXSTYLE) & WS_EX_TOOLWINDOW) == 0)
    {
        var l = GetWindowLong(hWnd, GWL_STYLE);
        SetWindowLong(hWnd, GWL_STYLE, (l | WS_MAXIMIZE) & (~WS_MINIMIZE));
        var maxPos = placement.MaxPosition;
        SetWindowPos(hWnd, IntPtr.Zero, maxPos.X, maxPos.Y, 0, 0, SetWindowPosFlags.AsynchronousWindowPosition | SetWindowPosFlags.DoNotActivate | SetWindowPosFlags.FrameChanged | SetWindowPosFlags.IgnoreResize | SetWindowPosFlags.IgnoreZOrder);
    }
}

The trick is to change the window state with SetWindowLong and redraw it with SetWindowPosFlags.FrameChanged. And in your case with SetWindowPosFlags.DoNotActivate.