软件进程只能存在一个

判断系统是否已经在运行了:      using System.Threading;

            bool bOnlyOneInstance = false;             Mutex mutex = new Mutex(true, Application.UserAppDataPath.Replace(@"/", "_"), out   bOnlyOneInstance);             if (!bOnlyOneInstance)             {                 MessageBox.Show("系统已经运行!", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);                 return;             }             else             {                 Application.EnableVisualStyles();                 Application.SetCompatibleTextRenderingDefault(false);                 Application.Run(new GBIM_Login());             }