c# 取消 Alt+F4（关闭窗口）源码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace CancelAltAndF4
{
    public partial class Frm_Main : Form
    {
        public Frm_Main（）
        {
            InitializeComponent（）;
        }

        private void Form1_KeyDown（object sender KeyEventArgs e）
        {
            if （e.Alt && e.KeyValue == 115）//如果按下的Alt和F4
                e.Handled = true;//不執行操作
        }
    }
}

 属性            大小     日期    时间   名称
----------- ---------  ---------- -----  ----
     目录           0  2017-08-29 20:42  CancelAltAndF4\
     目录           0  2017-08-28 18:24  CancelAltAndF4\CancelAltAndF4\
     文件         932  2012-12-19 15:19  CancelAltAndF4\CancelAltAndF4.sln
     文件         144  2012-12-19 15:20  CancelAltAndF4\CancelAltAndF4\app.config
     目录           0  2017-08-28 18:24  CancelAltAndF4\CancelAltAndF4\bin\
     目录           0  2017-08-28 18:24  CancelAltAndF4\CancelAltAndF4\bin\Debug\
     文件      256000  2012-12-19 15:23  CancelAltAndF4\CancelAltAndF4\bin\Debug\CancelAltAndF4.exe
     文件         144  2012-12-19 15:20  CancelAltAndF4\CancelAltAndF4\bin\Debug\CancelAltAndF4.exe.config
     文件       34304  2012-12-19 15:23  CancelAltAndF4\CancelAltAndF4\bin\Debug\CancelAltAndF4.pdb
     文件       14328  2010-08-25 13:18  CancelAltAndF4\CancelAltAndF4\bin\Debug\CancelAltAndF4.vshost.exe
     文件         490  2009-06-11 05:14  CancelAltAndF4\CancelAltAndF4\bin\Debug\CancelAltAndF4.vshost.exe.manifest
     目录           0  2012-12-19 15:19  CancelAltAndF4\CancelAltAndF4\bin\Release\
     文件        5573  2012-12-19 15:20  CancelAltAndF4\CancelAltAndF4\CancelAltAndF4.csproj
     文件         452  2012-12-19 15:20  CancelAltAndF4\CancelAltAndF4\CancelAltAndF4.csproj.user
     文件         561  2012-12-19 15:20  CancelAltAndF4\CancelAltAndF4\Frm_Main.cs
     文件        1950  2012-12-19 15:20  CancelAltAndF4\CancelAltAndF4\Frm_Main.designer.cs
     文件      377027  2010-12-09 08:50  CancelAltAndF4\CancelAltAndF4\Frm_Main.resx
     目录           0  2017-08-28 18:24  CancelAltAndF4\CancelAltAndF4\obj\
     目录           0  2017-08-28 18:24  CancelAltAndF4\CancelAltAndF4\obj\Debug\
     文件        3350  2012-12-19 15:23  CancelAltAndF4\CancelAltAndF4\obj\Debug\CancelAltAndF4.csproj.FileListAbsolute.txt
     文件         850  2010-12-09 08:50  CancelAltAndF4\CancelAltAndF4\obj\Debug\CancelAltAndF4.csproj.GenerateResource.Cache
     文件      256000  2012-12-19 15:23  CancelAltAndF4\CancelAltAndF4\obj\Debug\CancelAltAndF4.exe
     文件      247765  2012-12-19 15:23  CancelAltAndF4\CancelAltAndF4\obj\Debug\CancelAltAndF4.Frm_Main.resources
     文件       34304  2012-12-19 15:23  CancelAltAndF4\CancelAltAndF4\obj\Debug\CancelAltAndF4.pdb
     文件         180  2012-12-19 15:23  CancelAltAndF4\CancelAltAndF4\obj\Debug\CancelAltAndF4.Properties.Resources.resources
     文件        6312  2012-12-19 15:23  CancelAltAndF4\CancelAltAndF4\obj\Debug\DesignTimeResolveAssemblyReferencesInput.cache
     文件         768  2012-12-19 15:23  CancelAltAndF4\CancelAltAndF4\obj\Debug\GenerateResource.read.1.tlog
     文件         978  2012-12-19 15:23  CancelAltAndF4\CancelAltAndF4\obj\Debug\GenerateResource.write.1.tlog
     目录           0  2011-04-06 10:19  CancelAltAndF4\CancelAltAndF4\obj\Debug\Refactor\
     目录           0  2017-08-28 18:24  CancelAltAndF4\CancelAltAndF4\obj\Debug\TempPE\
     文件        4608  2012-12-19 15:20  CancelAltAndF4\CancelAltAndF4\obj\Debug\TempPE\Properties.Resources.Designer.cs.dll
............此处省略7个文件信息