鉤子其實就是調(diào)用一下API而已:
1、安裝鉤子:
SetWindowsHookEx
函數(shù)原形:HHOOK SetWindowsHookEx(
int idHook, // 鉤子類型,
HOOKPROC lpfn, // 鉤子函數(shù)地址
INSTANCE hMod, // 鉤子所在的實例的句柄,
DWORD dwThreadId // 鉤子所監(jiān)視的線程的線程號
)
hMod: 對于線程序鉤子,參數(shù)傳NULL;
對于系統(tǒng)鉤子:參數(shù)為鉤子DLL的句柄
dwThreadId:對于全局鉤子,該參數(shù)為NULL。
鉤子類型用WH_CALLWNDPROC=4(發(fā)送到窗口的消息。由SendMessage觸發(fā))
返回:成功:返回SetWindowsHookEx返回所安裝的鉤子句柄;
失?。篘ULL;
2、回調(diào),你要截獲消息就在這里進(jìn)行:
LRESULT WINAPI MyHookProc(
int nCode , // 指定是否需要處理該消息
WPARAM wParam, // 包含該消息的附加消息
LPARAM lParam // 包含該消息的附加消息
)
3、調(diào)用下一個鉤子
LRESULT CallNextHookEx(
HHOOK hhk, // 是您自己的鉤子函數(shù)的句柄。用該句柄可以遍歷鉤子鏈
int nCode, // 把傳入的參數(shù)簡單傳給CallNextHookEx即可
WPARAM wParam, // 把傳入的參數(shù)簡單傳給CallNextHookEx即可
LPARAM lParam // 把傳入的參數(shù)簡單傳給CallNextHookEx即可
);
4、用完后記得卸載鉤子哦,要不然你的系統(tǒng)會變得奇慢無比!
BOOL UnhookWindowsHookEx(
HHOOK hhk // 要卸載的鉤子句柄。
)
把上面這些API用C#封裝一下,就可以直接用了!
給個線程鉤子的例子吧(兩個Form都在同一個線程中運行):
using System.Runtime.InteropServices;
public class Form1 : System.Windows.Forms.Form
{
...
//定義委托(鉤子函數(shù),用于回調(diào))
public delegate int HookProc(int code, IntPtr wparam, ref CWPSTRUCT cwp);
//安裝鉤子的函數(shù)
[DllImport("User32.dll",CharSet = CharSet.Auto)]
public static extern IntPtr SetWindowsHookEx(int type, HookProc hook, IntPtr instance, int threadID);
//調(diào)用下一個鉤子的函數(shù)
[DllImport("User32.dll",CharSet = CharSet.Auto)]
public static extern int CallNextHookEx(IntPtr hookHandle, int code, IntPtr wparam, ref CWPSTRUCT cwp);
//卸載鉤子
[DllImport("User32.dll",CharSet = CharSet.Auto)]
public static extern bool UnhookWindowsHookEx(IntPtr hookHandle);
//獲取窗體線程ID
DllImport("User32.dll",CharSet = CharSet.Auto)]
public static extern int GetWindowThreadProcessId(IntPtr hwnd, int ID);
private HookProc hookProc;
private IntPtr hookHandle = IntPtr.Zero;
public Form1()
{
....
//掛接鉤子處理方法
this.hookProc = new HookProc(myhookproc);
}
//開始攔截
private bool StartHook()
{
Form2 f=new Form2();
f.Show();//加上這個
//安裝鉤子,攔截系統(tǒng)向Form2發(fā)出的消息
this.hookHandle = SetWindowsHookEx(4, hookProc, IntPtr.Zero ,GetWindowThreadProcessId(f.Handle,0));
return (this.hookHandle != 0);
}
//停止攔截
private bool StopHook()
{
return UnhookWindowsHookEx(this.hookHandle);
}
//鉤子處理函數(shù),在這里攔截消息并做處理
private int myhookproc(int code, IntPtr wparam, ref CWPSTRUCT cwp)
{
switch(code)
{
case 0:
switch(cwp.message)
{
case 0x0000F://WM_PAINT,攔截WM_PAINT消息
//do something
break;
}
break;
}
return CallNextHookEx(hookHandle,code,wparam, ref cwp);
}
[StructLayout(LayoutKind.Sequential)]
public struct CWPSTRUCT
{
public IntPtr lparam;
public IntPtr wparam;
public int message;
public IntPtr hwnd;
}
}
public class Form2 : System.Windows.Forms.Form
{
....
}
Trackback: http://tb.blog.csdn.net/TrackBack.aspx?PostId=714599