c# 防早退提醒器

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <appSettings>
    <add key="WorkingStartTime" value="8:30" />
    <add key="WorkingEndTime" value="17:30" />
    <add key="WorkingHours" value="8" />
    <add key="TotalRestHours" value="1" />
  </appSettings>
</configuration>

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using Microsoft.VisualBasic;
using System.IO;
using System.Diagnostics;
using System.Configuration;
using Microsoft.Win32;

namespace WorkAssistant
{
    public partial class frmMain : Form
    {
        [DllImport("kernel32.dll", CharSet = CharSet.Ansi)]
        private static extern IntPtr SetProcessShutdownParameters(int dwLevel, int dwFlags);

        private DateTime StartTime { get; set; }
        private DateTime WorkingStartTime { get; set; }
        private DateTime WorkingEndTime { get; set; }
        private bool ShutdownFlag { get; set; }
        public int WorkingHours { get; set; }
        public int TotalRestHours { get; set; }

        public frmMain()
        {
            InitializeComponent();
            this.WorkingHours = 8;
            this.TotalRestHours = 1;
        }

        void frmMain_FormClosing(object sender, FormClosingEventArgs e)
        {
            throw new NotImplementedException();
        }

        protected override void OnShown(EventArgs e)
        {
            base.OnShown(e);
            this.Hide();
        }

        protected override void WndProc(ref Message m)
        {
            const int WM_QUERYENDSESSION = 0x011;
            const int WM_ENDSESSION = 0x16;
            var reason = SessionEndReasons.SystemShutdown;

            if (ShutdownFlag)
            {
                base.WndProc(ref m);
                return;
            }

            if (m.Msg == WM_QUERYENDSESSION)
            {
                return;
            }
            else if (m.Msg == WM_ENDSESSION)
            {
                if (m.LParam.ToInt32() == 0)
                {
                    reason = SessionEndReasons.SystemShutdown;
                }
                else
                {
                    reason = SessionEndReasons.Logoff;
                }

                var workOffTime = WorkingEndTime;
                if (StartTime > WorkingStartTime)
                {
                    workOffTime = StartTime.AddHours(WorkingHours).AddHours(TotalRestHours);
                }
                if (workOffTime < WorkingEndTime)
                {
                    workOffTime = WorkingEndTime;
                }

                if (DateTime.Now < workOffTime)
                {
                    var msgResult = MessageBox.Show(string.Format("今天的开机时间是:{0},应该在{1}下班,工时还不足{2}小时，确定现在关机吗？", StartTime, workOffTime, WorkingHours), "关机确认", MessageBoxButtons.YesNo);
                    if (msgResult == System.Windows.Forms.DialogResult.Yes)
                    {
                        msgResult = MessageBox.Show(string.Format("今天的开机时间是:{0},应该在{1}下班,工时还不足{2}小时，确定现在关机吗？", StartTime, workOffTime, WorkingHours), "再次确认", MessageBoxButtons.YesNo);
                        if (msgResult != System.Windows.Forms.DialogResult.Yes)
                        {
                            return;
                        }
                    } 
                    else
                    {
                        return;
                    }
                }

                ShutdownFlag = true;

                base.WndProc(ref m);

                switch (reason)
                {
                    case SessionEndReasons.SystemShutdown:
                        Shutdown();
                        break;
                    case SessionEndReasons.Logoff:
                        Logoff();
                        break;
                    default:
                        Shutdown();
                        break;
                }
            }
            else
            { 
                base.WndProc(ref m);
            } 
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            IntPtr result = SetProcessShutdownParameters(0x4FF, 0);
            if (result.ToInt32() == 0)
            {
                //failed to set shutdown sequence
            }
            StartTime = GetStartTime();
            WorkingStartTime = Convert.ToDateTime(ConfigurationManager.AppSettings["WorkingStartTime"]);
            WorkingEndTime = Convert.ToDateTime(ConfigurationManager.AppSettings["WorkingEndTime"]);
            WorkingHours = Convert.ToInt32(ConfigurationManager.AppSettings["WorkingHours"]);
            TotalRestHours = Convert.ToInt32(ConfigurationManager.AppSettings["TotalRestHours"]);
        }

        public DateTime GetStartTime()
        {
            EventLog eventLog = new EventLog("system", ".");
            var startTime = eventLog.Entries.Cast<EventLogEntry>()
                .Where(item => item.TimeWritten > DateTime.Today)
                .Min(item => item.TimeWritten);
            return startTime;
        }

        public void Shutdown()
        {
            SystemManager.WindowsController.ExitWindows(SystemManager.RestartOptions.ShutDown, false);
        }

        public void Logoff()
        {
            SystemManager.WindowsController.ExitWindows(SystemManager.RestartOptions.LogOff, false);
        }
    }
}

原创，比较简单，关机的代码请参考的另一篇随笔，代码是一模一样的。