static class Program { static Mutex mx; static bool PreventReenterProcess(string ProcessMark) { bool IsSucess; mx = new Mutex(true, @"Global" + ProcessMark, out IsSucess); if (IsSucess) { return false; //返回false表示进程不存在。 } return true; } //应用程序的主入口点 [STAThread] static void Main() { string state = ConfigurationManager.AppSettings["multiple2"].ToString(); if (PreventReenterProcess(state)) { return; } Application.EnableVisualStyles(); Application.SetCompatibleTextRenderingDefault(false); Application.Run(new UpdateTimeForm()); } }