以下是我复制过来的,实现的效果是当用户在TextBox中输入 b 的时候,TextBox 始终显示 a
你把MyHookProc函数改一下就可以了,
IntPtr MyHookProc(int code, IntPtr wparam, IntPtr lparam)
{
if( code < 0 ) return CallNextHookEx(_nextHookPtr,code, wparam, lparam); //返回,让后面的程序处理该消息
return (IntPtr) 1; //直接返回了,该消息就处理结束
}
实现过程:
1、新建一个C#的WindowsApplication
2、在Form1中,添加下面一些变量:
internal enum HookType //枚举,钩子的类型
{
//MsgFilter = -1,
//JournalRecord = 0,
//JournalPlayback = 1,
Keyboard = 2,
//GetMessage = 3,
//CallWndProc = 4,
//CBT = 5,
//SysMsgFilter = 6,
//Mouse = 7,
//Hardware = 8,
//Debug = 9,
//Shell = 10,
//ForegroundIdle = 11,
//CallWndProcRet = 12,
//KeyboardLL = 13,
//MouseLL = 14,
};
IntPtr _nextHookPtr; //记录Hook编号
3、在Form1中引入必须的API
[DllImport("kernel32.dll")]
static extern int GetCurrentThreadId(); //取得当前线程编号的API
[DllImport("User32.dll")]
internal extern static void UnhookWindowsHookEx(IntPtr handle); //取消Hook的API
[DllImport("User32.dll")]
internal extern static IntPtr SetWindowsHookEx(int idHook, [MarshalAs(UnmanagedType.FunctionPtr)] HookProc lpfn, IntPtr hinstance, int threadID); //设置Hook的API
[DllImport("User32.dll")]
internal extern static IntPtr CallNextHookEx(IntPtr handle, int code, IntPtr wparam, IntPtr lparam); //取得下一个Hook的API
4、声明一个实现的委托
internal delegate IntPtr HookProc(int code, IntPtr wparam, IntPtr lparam);
5、添加自己的Hook处理过程
IntPtr MyHookProc(int code, IntPtr wparam, IntPtr lparam)
{
if( code < 0 ) return CallNextHookEx(_nextHookPtr,code, wparam, lparam); //返回,让后面的程序处理该消息
if( wparam.ToInt32() == 98 || wparam.ToInt32() == 66 ) //如果用户输入的是 b
{
this.textBox1.Text = "a";
return (IntPtr) 1; //直接返回了,该消息就处理结束了
}
else
{
return IntPtr.Zero; //返回,让后面的程序处理该消息
}
}
6、添加加入Hook链和从Hook链中取消的函数
public void SetHook()
{
if( _nextHookPtr != IntPtr.Zero ) //已经勾过了
return;
HookProc myhookProc = new HookProc(MyHookProc); //声明一个自己的Hook实现函数的委托对象
_nextHookPtr = SetWindowsHookEx((int)HookType.Keyboard, myhookProc , IntPtr.Zero , GetCurrentThreadId()); //加到Hook链中
}
public void UnHook()
{
if( _nextHookPtr != IntPtr.Zero )
{
UnhookWindowsHookEx(_nextHookPtr); //从Hook链中取消
_nextHookPtr = IntPtr.Zero;
}
}
7、在Form1的Load事件中添加 SetHook() , 在Form1的closing 事件中添加 UnHook()
private void Form1_Load(object sender, System.EventArgs e)
{
SetHook();
}
private void Form1_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
UnHook();
}