C#實現本機登出、關閉、重啟

[DllImport("user32.dll", EntryPoint = "ExitWindowsEx", CharSet = CharSet.Ansi)]
 private static extern int ExitWindowsEx(int uFlags, int dwReserved);

 //登出電腦
        public void logout()
        {
            ExitWindowsEx(0, 0);  //調用API實現
        }
        //關閉電腦（通過CMD命令實現）
        public void closepc()
        {
            //建立存取控制本地系統進程的對象執行個體
            System.Diagnostics.Process myprocess = new System.Diagnostics.Process();
            myprocess.StartInfo.FileName = "cmd.exe";
            myprocess.StartInfo.UseShellExecute = false;
            myprocess.StartInfo.RedirectStandardInput = true;
            myprocess.StartInfo.RedirectStandardOutput = true;
            myprocess.StartInfo.RedirectStandardError = true;
            myprocess.StartInfo.CreateNoWindow = true;
            myprocess.Start();
            myprocess.StandardInput.WriteLine("shutdown -s -t 0");
        }
        //重新啟動電腦（通過CMD命令實現）
        public void afreshstartpc()
        {
            //建立存取控制本地系統進程的對象執行個體
            System.Diagnostics.Process myprocess = new System.Diagnostics.Process();
            myprocess.StartInfo.FileName = "cmd.exe";
            myprocess.StartInfo.UseShellExecute = false;
            myprocess.StartInfo.RedirectStandardInput = true;
            myprocess.StartInfo.RedirectStandardOutput = true;
            myprocess.StartInfo.RedirectStandardError = true;
            myprocess.StartInfo.CreateNoWindow = true;
            myprocess.Start();
            myprocess.StandardInput.WriteLine("shutdown -r -t 0");
        }