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

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.