Winform禁止程序多开 &&禁止多开且第二次激活第一次窗口

一、禁止多开问题，运用Mutex锁

在Program.cs中运用Mutex锁

bool createNew;
using (System.Threading.Mutex mutex = new System.Threading.Mutex(true, Application.ProductName, out createNew))
{
     if (createNew)
     {
          Application.Run(new Form1());
     }
     else
     {
          MessageBox.Show("应用程序已经在运行中...")
          System.Threading.Thread.Sleep(1000);
          System.Environment.Exit(1);
     }
}

或者

static void Main()
{
     Application.EnableVisualStyles();
     Application.SetCompatibleTextRenderingDefault(false);
     //Application.Run(new MainForm());

      bool CreateNewForm;//返回是否赋予了使用线程的互斥体初始所属权 
      System.Threading.Mutex instance = new System.Threading.Mutex(true, "MutexName", out CreateNewForm);//同步基元变量 
      if (CreateNewForm)//赋予了线程初始所属权，也就是首次使用互斥体
      {
           Application.Run(new MainForm());
           instance.ReleaseMutex();
      }
      else
      {
           Application.Exit();
      }
}

二、禁止多开且第二次点击激活第一次窗口运用句柄

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Diagnostics;
using System.Reflection;

namespace NetCardUI
{
    static class Program
    {
        ///<summary>
        /// 该函数设置由不同线程产生的窗口的显示状态
        /// </summary>
        /// <param name="hWnd">窗口句柄</param>
        /// <param name="cmdShow">指定窗口如何显示。查看允许值列表，请查阅ShowWlndow函数的说明部分</param>
        /// <returns>如果函数原来可见，返回值为非零；如果函数原来被隐藏，返回值为零</returns>
        [DllImport("User32.dll")]
        private static extern bool ShowWindowAsync(IntPtr hWnd, int cmdShow);

        /// <summary>
        ///  该函数将创建指定窗口的线程设置到前台，并且激活该窗口。键盘输入转向该窗口，并为用户改各种可视的记号。
        ///  系统给创建前台窗口的线程分配的权限稍高于其他线程。 
        /// </summary>
        /// <param name="hWnd">将被激活并被调入前台的窗口句柄</param>
        /// <returns>如果窗口设入了前台，返回值为非零；如果窗口未被设入前台，返回值为零</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);//显示
            SetForegroundWindow(instance.MainWindowHandle);//设置到最前端
        }
        private static Process RuningInstance()
        {
            Process currentProcess = Process.GetCurrentProcess();
            Process[] Processes = Process.GetProcessesByName(currentProcess.ProcessName);
            foreach (Process process in Processes)
            {
                if (process.Id != currentProcess.Id)
                {
                    if (Assembly.GetExecutingAssembly().Location.Replace("/", "\") == currentProcess.MainModule.FileName)
                    {
                        return process;
                    }
                }
            }
            return null;
        }
        /// <summary>
        /// 应用程序的主入口点。
        /// </summary>
        [STAThread]
        static void Main()
        {
            Process process = RuningInstance();
            if (process == null)
            {
                Application.Run(new MainForm());
            }
            else
            {
                HandleRunningInstance(process);
                //System.Threading.Thread.Sleep(1000);
                //System.Environment.Exit(1);
            }
        }
    }                
}