如果想用代码来控制计算机关闭该如何实现呢？
给个实例！
谢谢……

还是不行！
那位高手给个有注释的实例来学习一下！
谢谢……

using System;
using System.Collections.Generic;
using
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using
using System.Runtime.InteropServices;

namespace WindowsApplication2
{
    public partial class Form1 : Form
    {
        string dateTimer = null;
        string date = null;
        public Form1()
        {
            InitializeComponent();
            lblTime.Text = DateTime.Now.ToShortTimeString();
        }

        [StructLayout(LayoutKind.Sequential, Pack = 1)]
        //获取计算机
        internal struct TokPriv1Luid
        {
            public int Count;

            public long Luid;

            public int Attr;

        }

        [DllImport("kernel32.dll", ExactSpelling = true)]

        internal static extern IntPtr GetCurrentProcess();

        [DllImport("advapi32.dll", ExactSpelling = true, SetLastError = true)]

        internal static extern bool OpenProcessToken(IntPtr h, int acc, ref       IntPtr phtok);

        [DllImport("advapi32.dll", SetLastError = true)]

        internal static extern bool LookupPrivilegeValue(string host, string name, ref       long pluid);

        [DllImport("advapi32.dll", ExactSpelling = true, SetLastError = true)]

        internal static extern bool AdjustTokenPrivileges(IntPtr htok, bool disall,

        ref       TokPriv1Luid newst, int len, IntPtr prev, IntPtr relen);

        [DllImport("user32.dll", ExactSpelling = true, SetLastError = true)]

        internal static extern bool ExitWindowsEx(int flg, int rea);

        internal const int SE_PRIVILEGE_ENABLED = 0x00000002;

        internal const int TOKEN_QUERY = 0x00000008;

        internal const int TOKEN_ADJUST_PRIVILEGES = 0x00000020;

        internal const string SE_SHUTDOWN_NAME = "SeShutdownPrivilege";

        internal const int EWX_LOGOFF = 0x00000000;//注消

        internal const int EWX_SHUTDOWN = 0x00000001;//保存后关机

        internal const int EWX_REBOOT = 0x00000002;//重启

        internal const int EWX_FORCE = 0x00000004;//不保存就关机

        internal const int EWX_POWEROFF = 0x00000008;//强制关机

        internal const int EWX_FORCEIFHUNG = 0x00000010;



        private void DoExitWin(int flg)
        {

            bool ok;

            TokPriv1Luid tp;

            IntPtr hproc = GetCurrentProcess();

            IntPtr htok = IntPtr.Zero;

            ok = OpenProcessToken(hproc, TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, ref       htok);

            tp.Count = 1;

            tp.Luid = 0;

            tp.Attr = SE_PRIVILEGE_ENABLED;

            ok = LookupPrivilegeValue(null, SE_SHUTDOWN_NAME, ref       tp.Luid);

            ok = AdjustTokenPrivileges(htok, false, ref       tp, 0, IntPtr.Zero, IntPtr.Zero);

            ok = ExitWindowsEx(flg, 0);

        }   
        private void btnCloseSystem_Click(object sender, EventArgs e)
        {
            if (txtDateTimer.Text == "")
            {
                MessageBox.Show("关机时间不能为空！");
                return;
            }
            txtDateTimer.Enabled = false;
            dateTimer = DateTime.Parse(txtDateTimer.Text).ToShortTimeString();
        }

        private void timeDateTime_Tick(object sender, EventArgs e)
        {
            //获取当前时间
            lblTime.Text = DateTime.Now.ToShortTimeString();
            date = DateTime.Now.ToShortTimeString();
        }

        private void timerDate_Tick(object sender, EventArgs e)
        {
            //关机
            if (txtDateTimer.Enabled == false)
            {
                if (dateTimer == date)
                {
                    //MessageBox.Show("UUUUUUUUU");
                    DoExitWin(EWX_SHUTDOWN);
                     
                }
            }

        }
        // 清空
        private void btnBare_Click(object sender, EventArgs e)
        {
            txtDateTimer.Enabled = true;
            txtDateTimer.Text = null;
        }
        
具体代码已经搞定！这是我在网上找到的，所有没多少注释，
实话说我也不都上面那一段！

这的我打包好的！