C#简单的关机程序，除了关机功能外，还包括了注销系统、重启系统，重新启动计算机windows，用到了计时器，用来每1秒钟更新一次TextBox上显示的系统运行时间。-C# simple shutdown procedures, in addition to the shutdown function, but also includes the write-off system, reboot the system, restart your computer windows, use a ti