深入分析C#键盘勾子(Hook),屏蔽键盘活动的详解
using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
using System.Reflection;
using System.Diagnostics;
using Microsoft.Win32;
using System.Windows.Forms;
namespace Vjsdn.Tech.KeyboardHook
{
///
/// 键盘Hook管理类, by www.vjsdn.com 易学原创
///
public class KeyboardHookLib
{
private const int WH_KEYBOARD_LL = 13; //键盘
//键盘处理事件托 ,当捕获键盘输入时调用定义该托的方法.
private delegate int HookHandle(int nCode, int wParam, IntPtr lParam);
//客户端键盘处理事件
public delegate void ProcessKeyHandle(HookStruct param, out bool handle);
//接收SetWindowsHookEx返回值
private static int _hHookValue = 0;
//勾子程序处理事件
private HookHandle _KeyBoardHookProcedure;
//Hook结构
[StructLayout(LayoutKind.Sequential)]
public class HookStruct
{
public int vkCode;
public int scanCode;
public int flags;
public int time;
public int dwExtraInfo;
}
//设置钩子
[DllImport("user32.dll")]
private static extern int SetWindowsHookEx(int idHook, HookHandle lpfn, IntPtr hInstance, int threadId);
//取消钩子
[DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
private static extern bool UnhookWindowsHookEx(int idHook);
//调用下一个钩子
[DllImport("user32.dll")]
private static extern int CallNextHookEx(int idHook, int nCode, int wParam, IntPtr lParam);
//获取当前线程ID
[DllImport("kernel32.dll")]
private static extern int GetCurrentThreadId();
//Gets the main module for the associated process.
[DllImport("kernel32.dll")]
private static extern IntPtr GetModuleHandle(string name);
private IntPtr _hookWindowPtr = IntPtr.Zero;
//构造器
public KeyboardHookLib() { }
//外部调用的键盘处理事件
private static ProcessKeyHandle _clientMethod = null;
///
/// 安装勾子
///
/// 外部调用的键盘处理事件
public void InstallHook(ProcessKeyHandle clientMethod)
{
_clientMethod = clientMethod;
// 安装键盘钩子
if (_hHookValue == 0)
{
_KeyBoardHookProcedure = new HookHandle(OnHookProc);
_hookWindowPtr = GetModuleHandle(Process.GetCurrentProcess().MainModule.ModuleName);
_hHookValue = SetWindowsHookEx(
WH_KEYBOARD_LL,
_KeyBoardHookProcedure,
_hookWindowPtr,
0);
//如果设置钩子失败.
if (_hHookValue == 0) UninstallHook();
}
}
//取消钩子事件
public void UninstallHook()
{
if (_hHookValue != 0)
{
bool ret = UnhookWindowsHookEx(_hHookValue);
if (ret) _hHookValue = 0;
}
}
//钩子事件内部调用,调用_clientMethod方法转发到客户端应用。
private static int OnHookProc(int nCode, int wParam, IntPtr lParam)
{
if (nCode >= 0)
{
//转换结构
HookStruct hookStruct = (HookStruct)Marshal.PtrToStructure(lParam, typeof(HookStruct));
if (_clientMethod != null)
{
bool handle = false;
//调用客户提供的事件处理程序。
_clientMethod(hookStruct, out handle);
if (handle) return 1; //1:表示键盘,return 退出
}
}
return CallNextHookEx(_hHookValue, nCode, wParam, lParam);
}
}
}