只运行一个窗体 并在一次点击时 显示到最前

发现用

SetForegroundWindow 并不是稳定的有效 

最后使用 SetWindowPos

贴码了

   public const int HWND_TOPMOST = -1;



        public const int HWND_NOTOPMOST = -2;



        protected override void OnStartup(StartupEventArgs e)




        {







            bool isNewInstance;



            base.OnStartup(e);



            Mutex mutex = new Mutex(true, "Single", out isNewInstance);



            if (isNewInstance != true) 



            {



                IntPtr intPtr = FindWindowW(null, "Single");



                if (intPtr != IntPtr.Zero)



                {











                    SetWindowPos(intPtr, HWND_TOPMOST, 0, 0, 0, 0, 1 | 2);



                    SetWindowPos(intPtr, HWND_NOTOPMOST, 0, 0, 0, 0, 1 | 2);



                    SetForegroundWindow(intPtr);







                }







                Shutdown();



            }



        }



        [DllImport("User32", CharSet = CharSet.Unicode)]



        static extern IntPtr FindWindowW(String lpClassName, String lpWindowName);



        [DllImport("User32", CharSet = CharSet.Unicode)]



        static extern Boolean SetForegroundWindow(IntPtr hWnd); 



        [DllImport("user32.dll", CharSet = CharSet.Auto)] 



        private static extern int SetWindowPos(IntPtr hWnd, int hWndInsertAfter, int x, int y, int Width, int Height, int flags);







        [DllImport("user32.dll")]



        public static extern IntPtr SetFocus(IntPtr hWnd);

代码：

https://download.csdn.net/download/q465162770/12003540

WPF 精修篇 窗体唯一（Single） 显示在最前