C# .NET锁屏程序（顺带屏蔽任务管理器）


		第一步：将窗体的FormBorderStyle设置为none，WindowState设为Maximized
占据整个屏幕。
第二步：使用钩子监控全局键盘事件。即屏蔽掉大部分系统热键。但是屏蔽ctrl+alt+del 任务管理器则较复杂，这个特例后面讨论。
使用全局钩子应该注意的地方：将代码放到一个独立的类库里面（只有dll才能被注射到其他进程中）。
using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
using System.IO;
using System.Reflection;
namespace KeyboardHookDLL
{
    public class KeyboardHook
    {
        public delegate int KeyboardProc(int nCode, IntPtr wParam, IntPtr lParam);
        static int hKeyboardHook = 0;
        KeyboardProc KeyboardHookProcedure;
        /// <summary>
        /// 钩子函数,需要引用空间(using System.Reflection;)
        /// 线程钩子监听键盘消息设为2,全局钩子监听键盘消息设为13
        /// 线程钩子监听鼠标消息设为7,全局钩子监听鼠标消息设为14
        /// </summary>
        public const int WH_KEYBOARD = 13;
        public const int WH_MOUSE_LL = 14;
        public struct KeyboardMSG
        {
            public int vkCode;
            public int scanCode;
            public int flags;
            public int time;
            public int dwExtraInfo;
        }
        //private FileStream MyFs;
//各种键位的ASC码
        private const byte LLKHF_ALTDOWN = 0x20;
        private const byte VK_CAPITAL = 0x14;
        private const byte VK_ESCAPE = 0x1B;
        private const byte VK_F4 = 0x73;
        private const byte VK_LCONTROL = 0xA2;
        private const byte VK_NUMLOCK = 0x90;
        private const byte VK_RCONTROL = 0xA3;
        private const byte VK_SHIFT = 0x10;
        private const byte VK_TAB = 0x09;
        //public const int WH_KEYBOARD = 13;
        private const int WH_KEYBOARD_LL = 13;
        private const int WH_MOUSE = 7;
        //private const int WH_MOUSE_LL = 14;
        private const int WM_KEYDOWN = 0x100;
        private const int WM_KEYUP = 0x101;
        private const int WM_LBUTTONDBLCLK = 0x203;
        private const int WM_LBUTTONDOWN = 0x201;
        private const int WM_LBUTTONUP = 0x202;
        private const int WM_MBUTTONDBLCLK = 0x209;
        private const int WM_MBUTTONDOWN = 0x207;
        private const int WM_MBUTTONUP = 0x208;
        private const int WM_MOUSEMOVE = 0x200;
        private const int WM_MOUSEWHEEL = 0x020A;
        private const int WM_RBUTTONDBLCLK = 0x206;
        private const int WM_RBUTTONDOWN = 0x204;
        private const int WM_RBUTTONUP = 0x205;
        private const int WM_SYSKEYDOWN = 0x104;
        private const int WM_SYSKEYUP = 0x105;
        //private static int hKeyboardHook = 0;
        /// <summary>
        /// vs2008中的声明方法，在vs2010中略有不同
        /// </summary>
        /// <returns></returns>
        [DllImport("kernel32")]
        public static extern int GetCurrentThreadId();
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention =
CallingConvention.StdCall)]
        public static extern int SetWindowsHookEx(int idHook, KeyboardProc lpfn, IntPtr
hInstance, int threadId);
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention =
CallingConvention.StdCall)]
        public static extern bool UnhookWindowsHookEx(int idHook);
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        public static extern int CallNextHookEx(int idHook, int nCode, IntPtr wParam, IntPtr lParam);
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.Winapi)]
        public static extern short GetKeyState(int keycode);
//在这里你可以自己定义要拦截的键。
        private int KeyboardHookProc(int nCode, IntPtr wParam, IntPtr lParam)
        {
            KeyboardMSG m = (KeyboardMSG)Marshal.PtrToStructure(lParam, typeof(KeyboardMSG));
            if (
            ((int)m.vkCode == 91) || ((int)m.vkCode == 92) ||
            ((m.vkCode == VK_TAB) && ((m.flags & LLKHF_ALTDOWN) != 0)) ||
            ((m.vkCode == VK_ESCAPE) && ((m.flags & LLKHF_ALTDOWN) != 0)) ||
            ((m.vkCode == VK_F4) && ((m.flags & LLKHF_ALTDOWN) != 0)) ||
            (m.vkCode == VK_ESCAPE) && ((GetKeyState(VK_LCONTROL) & 0x8000) != 0) ||
            (m.vkCode == VK_ESCAPE) && ((GetKeyState(VK_RCONTROL) & 0x8000) != 0)
            )
            {
         return 1;
            }
            return CallNextHookEx(hKeyboardHook, nCode, wParam, lParam);
   &nb

补充：软件开发 , C# ,