.net cs程序仅启动一次的方法

方法一.

private Boolean IsFirstInstance()
{
if (System.Diagnostics.Process.GetProcessesByName(Application.ProductName).Length
> 1)
{
return false;
}
return true;
}

方法二

    private static bool HaveOtherInstance()
        {
            try
            {
                EventWaitHandle globalHandler = EventWaitHandle.OpenExisting("iReaper");
                globalHandler.Set();
                return true;
            }
            catch (WaitHandleCannotBeOpenedException)
            {
                EventWaitHandle global = new EventWaitHandle(true, EventResetMode.AutoReset, "iReaper");
                Thread monitor = new Thread(new ThreadStart(delegate()
                {
                    while (true)
                    {
                        global.WaitOne();
                     }
                }));
                monitor.IsBackground = true;
                monitor.Start();
                GC.KeepAlive(monitor);
                return false;
            }
        }

 

方法三

<!--StartFragment-->public static Process RunningInstance() 
{ 
     Process current = Process.GetCurrentProcess();
     Process[] processes = Process.GetProcessesByName (current.ProcessName);
      //Loop through the running processes in with the same name

      foreach (Process process in processes)
       { 
          //Ignore the current process
            if (process.Id != current.Id)
           {
                //Make sure that the process is running from the exe file.
                 if (Assembly.GetExecutingAssembly().Location.Replace("/", "//") == current.MainModule.FileName)
                 {
                     //Return the other process instance.
                     return process;
                 }
            }
       }
       //No other instance was found, return null.
       return null;
}

分析：方法一和方法三从本质上说 是一样的，是在当前运行进程中是否存在同名或地址相同进程，若没有则说明程序第一次运行。方法二不同，是在当前进程中另运行一个模块，同时设置一个线程同步变量。程序运行时，查看是否存在某一名称变量。