只允许运行一个实例（C#）

 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;
                    }

                }
            }
            return null;
        }

 

然后在启动的位置写：

 Process instance = RunningInstance();
            if(instance == null)
            {

                 Application.Run(new FrmMain());//启动窗体

            }else

            {

                    Application.Exit();

 

             }