System.Diagnostics.Process.CloseMainWindowCore C# (CSharp) Method

        private bool CloseMainWindowCore()
        {
            const int GWL_STYLE = -16; // Retrieves the window styles.
            const int WS_DISABLED = 0x08000000; // WindowStyle disabled. A disabled window cannot receive input from the user.
            const int WM_CLOSE = 0x0010; // WindowMessage close.

            IntPtr mainWindowHandle = MainWindowHandle;
            if (mainWindowHandle == (IntPtr)0)
            {
                return false;
            }

            int style = Interop.User32.GetWindowLong(mainWindowHandle, GWL_STYLE);
            if ((style & WS_DISABLED) != 0)
            {
                return false;
            }

            Interop.User32.PostMessage(mainWindowHandle, WM_CLOSE, IntPtr.Zero, IntPtr.Zero);
            return true;
        }