C# 键盘钩子
1、键盘钩子：
通过代码将键盘的事件屏蔽掉，达到锁屏的效果。（参考地址：https://zhidao.baidu.com/question/135132386108196965.html）
2、代码如下：
public class Hook : IDisposable{public delegate int HookProc(int nCode, int wParam, IntPtr lParam);private static int hHook;public const int WH_KEYBOARD_LL = 13;private HookProc KeyBoardHookProcedure;[StructLayout(LayoutKind.Sequential)]public class KeyBoardHookStruct{public int vkCode;public int scanCode;public int flags;public int time;public int dwExtraInfo;}[DllImport("user32.dll")]public static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);[DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]public static extern bool UnhookWindowsHookEx(int idHook);[DllImport("user32.dll")]public static extern int CallNextHookEx(int idHook, int nCode, int wParam, IntPtr lParam);[DllImport("kernel32.dll")]public static extern IntPtr GetModuleHandle(string name);public void Start(){// 安装键盘钩子if (hHook == 0){KeyBoardHookProcedure = KeyBoardHookProc;hHook = SetWindowsHookEx(WH_KEYBOARD_LL, KeyBoardHookProcedure,GetModuleHandle(Process.GetCurrentProcess().MainModule.ModuleName), 0);//如果设置钩子失败.if (hHook == 0){Close();}else{var key = Registry.CurrentUser.OpenSubKey(@"Software\Microsoft\Windows\CurrentVersion\Policies\System", true);if (key == null) //如果该项不存在的话，则创建该项key = Registry.CurrentUser.CreateSubKey(@"Software\Microsoft\Windows\CurrentVersion\Policies\System");key.SetValue("DisableTaskMgr", 1, RegistryValueKind.DWord);key.Close();}}}public void Close(){var retKeyboard = true;if (hHook != 0){retKeyboard = UnhookWindowsHookEx(hHook);hHook = 0;}//如果去掉钩子失败.//if (!retKeyboard) throw new Exception("UnhookWindowsHookEx failed.");var key = Registry.CurrentUser.OpenSubKey(@"Software\Microsoft\Windows\CurrentVersion\Policies\System",true);if (key != null){key.DeleteValue("DisableTaskMgr", false);key.Close();}}public static int KeyBoardHookProc(int nCode, int wParam, IntPtr lParam){if (nCode >= 0){var kbh = (KeyBoardHookStruct) Marshal.PtrToStructure(lParam, typeof(KeyBoardHookStruct));if (kbh.vkCode == 91) // 截获左win(开始菜单键)return 1;if (kbh.vkCode == 92) // 截获右winreturn 1;if (kbh.vkCode == (int) Keys.Escape && (int) Control.ModifierKeys == (int) Keys.Control) //截获Ctrl+Escreturn 1;if (kbh.vkCode == (int) Keys.F4 && (int) Control.ModifierKeys == (int) Keys.Alt) //截获alt+f4return 1;if (kbh.vkCode == (int) Keys.Tab && (int) Control.ModifierKeys == (int) Keys.Alt) //截获alt+tabreturn 1;if (kbh.vkCode == (int) Keys.Escape &&(int) Control.ModifierKeys == (int) Keys.Control + (int) Keys.Shift) //截获Ctrl+Shift+Escreturn 1;if (kbh.vkCode == (int) Keys.Space && (int) Control.ModifierKeys == (int) Keys.Alt) //截获alt+空格return 1;if (kbh.vkCode == 241) //截获F1return 1;if (kbh.vkCode == (int) Keys.Control && kbh.vkCode == (int) Keys.Alt && kbh.vkCode == (int) Keys.Delete)return 1;if ((int) Control.ModifierKeys == (int) Keys.Control + (int) Keys.Alt + (int) Keys.Delete) //截获Ctrl+Alt+Deletereturn 1;if ((int) Control.ModifierKeys == (int) Keys.Control + (int) Keys.Shift) //截获Ctrl+Shiftreturn 1;}return CallNextHookEx(hHook, nCode, wParam, lParam);}#region IDisposable 成员public void Dispose(){Close();}#endregion}
