How to keep window always on top

Question

How I can keep my window staying always on top even if there is a window of another application with Topmost = true option activated and trying to stay in front

Answer 1

You can do a platform invoke on BringWindowToTop to achieve this:

[DllImport("user32.dll", SetLastError=true)]
static extern bool BringWindowToTop(IntPtr hWnd);

[DllImport("user32.dll", SetLastError=true)]
static extern bool BringWindowToTop(HandleRef hWnd);

And call to it when the FocusLost event fires.