ModernWPF.Internal.LegacyBorderManager.HandleNcActivate C# (CSharp) Method

        private IntPtr HandleNcActivate(IntPtr hwnd, int msg, IntPtr wParam, IntPtr retVal)
        {
            //Debug.WriteLine(hwnd.ToInt64() + " wparam " + wParam.ToInt32());

            if (wParam == BasicValues.FALSE)
            {
                retVal = BasicValues.TRUE;
            }
            else
            {
                // Also skip default wndproc on maximized window to prevent non-dwm theme titlebar being drawn
                if (_contentWindow.WindowState != WindowState.Maximized ||
                    Dwmapi.IsCompositionEnabled)
                {
                    retVal = User32.DefWindowProc(hwnd, (uint)msg, wParam, new IntPtr(-1));
                }
            }
            return retVal;
        }