C#應用程序單例並激活程序的窗口 使其顯示在最前端

 public class SoftHelper
    {
        ///<summary>
        /// 該函數設置由不一樣線程產生的窗口的顯示狀態
        /// </summary>
        /// <param name="hWnd">窗口句柄</param>
        /// <param name="cmdShow">指定窗口如何顯示。查看容許值列表，請查閱ShowWlndow函數的說明部分</param>
        /// <returns>若是函數原來可見，返回值爲非零；若是函數原來被隱藏，返回值爲零</returns>
        [DllImport("User32.dll")]
        private static extern bool ShowWindowAsync(IntPtr hWnd, int cmdShow);


        /// <summary>
        ///  該函數將建立指定窗口的線程設置到前臺，而且激活該窗口。鍵盤輸入轉向該窗口，併爲用戶改各類可視的記號。
        ///  系統給建立前臺窗口的線程分配的權限稍高於其餘線程。 
        /// </summary>
        /// <param name="hWnd">將被激活並被調入前臺的窗口句柄</param>
        /// <returns>若是窗口設入了前臺，返回值爲非零；若是窗口未被設入前臺，返回值爲零</returns>
        [DllImport("User32.dll")]
        private static extern bool SetForegroundWindow(IntPtr hWnd);



        private const int SW_SHOWNOMAL = 1;
        private static void HandleRunningInstance(Process instance)
        {
            ShowWindowAsync(instance.MainWindowHandle, SW_SHOWNOMAL);//顯示
            SetForegroundWindow(instance.MainWindowHandle);//當到最前端
        }

        private static Process RuningInstance()
        {
            Process currentProcess = Process.GetCurrentProcess();
            Process[] Processes = Process.GetProcessesByName(currentProcess.ProcessName);

            foreach (Process process in Processes)
            {
                if (process.Id != currentProcess.Id)
                {
                    return process;
                }
            }
       

            return null;
        }

       /// <summary>
       /// 程序以單例運行 
       /// </summary>
       public static void SoftSingle<T>() where T:Form, new()
       {
            Process process = RuningInstance();
            if(process==null)
            {
                var mainForm = new T();
                Application.Run(mainForm);
            }
            else
            {
                HandleRunningInstance(process);
            }
        }


    }

調用爲：SoftHelper.SoftSingle<Main>();