Make a window topmost using a window handle
Solution 1:
You need to use P/Invoke with SetWindowPos to accopmlish this:
[DllImport("user32.dll")]
static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int X, int Y, int cx, int cy, uint uFlags);
static readonly IntPtr HWND_TOPMOST = new IntPtr(-1);
const UInt32 SWP_NOSIZE = 0x0001;
const UInt32 SWP_NOMOVE = 0x0002;
const UInt32 SWP_SHOWWINDOW = 0x0040;
// Call this way:
SetWindowPos(theWindowHandle, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE | SWP_SHOWWINDOW);