C# 禁止ALT+F4(钩子)

1. Windows Forms中禁用窗体的关闭按钮 
添加必要的命名空间：
using System.Runtime.InteropServices;  
添加必要的常数和API函数的引用
private const int SC_CLOSE = 0xF060;
private const int MF_ENABLED = 0x00000000; private const int MF_GRAYED = 0x00000001; private const int MF_DISABLED = 0x00000002;  
[DllImport("user32.dll", EntryPoint = "GetSystemMenu")]
private static extern IntPtr GetSystemMenu(IntPtr hWnd, int bRevert); [DllImport("User32.dll")]
public static extern bool EnableMenuItem(IntPtr hMenu, int uIDEnableItem, int uEnable); 
在窗体的Load事件处理函数内添加代码
private void Form6_Load(object sender, EventArgs e) {
   IntPtr hMenu = GetSystemMenu(this.Handle, 0);
   EnableMenuItem(hMenu, SC_CLOSE, MF_DISABLED | MF_GRAYED); }  
2. Windows Forms中禁用窗体的关闭按钮和ALT+F4关闭

protected override CreateParams CreateParams {    get    {
      const int CS_NOCLOSE = 0x200;       CreateParams cp = base.CreateParams;       cp.ClassStyle = cp.ClassStyle | CS_NOCLOSE;       return cp;    } } 
3.不允许拖动窗体和最大化最小化按钮
        protected override void WndProc(ref Message m)         {
            base.WndProc(ref m);
            if (m.Msg == 0x84 && m.Result == (IntPtr)2) // 不让拖动标题栏             {
                m.Result = (IntPtr)1;             }
            if (m.Msg == 0xA3)                         // 双击标题栏无反应             {
                m.WParam = System.IntPtr.Zero;             }         }

///////////////////////////////////////////////////////////////////////////////////////////////////////// 钩子 
我用的是全局键盘钩子。这个程序可以屏蔽win和alt+f4但是不能屏蔽ctrl+alt+del。我一直在找屏蔽ctrl+alt+del的方法希望会的人指点一下。用了 form_load事件和Form1_FormClosing事件 using System;
using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Text;
using System.Windows.Forms; using System.Runtime.InteropServices; using System.Reflection; 
namespace WindowsApplication10 {
    public partial class Form1 : Form     {
        // 安装钩子 
        [DllImport("user32.dll")]
        public static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);         // 卸载钩子 
        [DllImport("user32.dll")]
        public static extern bool UnhookWindowsHookEx(int idHook);         // 继续下一个钩子          [DllImport("user32.dll")]
        public static extern int CallNextHookEx(int idHook, int nCode, Int32 wParam, IntPtr lParam); 
        //声明定义
        public delegate int HookProc(int nCode, Int32 wParam, IntPtr lParam);         static int hKeyboardHook = 0;         HookProc KeyboardHookProcedure; 
        public Form1()         {
            InitializeComponent();         }

private void Form1_Load(object sender, EventArgs e)         {
            HookStart();         } 
        private void Form1_FormClosing(object sender, FormClosingEventArgs e)         {
            HookStop();         } 
        // 安装钩子 
        public void HookStart()         {
            if (hKeyboardHook == 0)             {
                // 创建HookProc实例 
                KeyboardHookProcedure = new HookProc(KeyboardHookProc);                 //定义全局钩子
                hKeyboardHook = SetWindowsHookEx(13, KeyboardHookProcedure, Marshal.GetHINSTANCE(Assembly.GetExecutingAssembly().GetModules()[0]), 0);                 if (hKeyboardHook == 0)                 {
                    HookStop();
                    throw new Exception("SetWindowsHookEx failed.");                 }             }         }
 
        //钩子子程就是钩子所要做的事情。
        private int KeyboardHookProc(int nCode, Int32 wParam, IntPtr lParam)         {
            //这里可以添加别的功能的代码             return 1;         }
       
        // 卸载钩子 
        public void HookStop()         {
            bool retKeyboard = true;             if (hKeyboardHook != 0)             {

retKeyboard = UnhookWindowsHookEx(hKeyboardHook);                 hKeyboardHook = 0;             }
            if (!(retKeyboard)) throw new Exception("UnhookWindowsHookEx failed.");         }     }
}   
////////////////////////////////////////////////////////
//这个是仅仅屏掉alt f4
if(e.KeyCode == Keys.F4 && e.Modifiers==Keys.Alt)  { 
e.Handled=true;  } 
//这个是不让窗口以任何方式退出
  class   Test   :   System.Windows.Forms.Form      {   
      protected   override   void  
OnClosing(System.ComponentModel.CancelEventArgs   e)          {   
          e.Cancel   =   true;          }        
      static   void   Main()          {   
          System.Windows.Forms.Application.Run(new   Test());          }      }