windows api学习笔记-键盘钩子

DLL项目的头文件

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#ifdef KEYHOOKLIB_EXPORT //此宏将在CPP文件中定义

#define KEYHOOKLIB_API __declspec(dllexport)

#else

#define KEYHOOKLIB_API __declspec(dllimport)

#endif

 

#define HM_KEY WM_USER+101

 

BOOL KEYHOOKLIB_API WINAPI SetKeyHook(BOOL bInstall,DWORD dwThreadId = 0,HWND hWndCaller=NULL);

DLL项目CPP文件

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#include <windows.h>

#define KEYHOOKLIB_EXPORT

#include "a.h"

 

#pragma data_seg("MyShared")//用共享数据段来保存主窗口句柄和钩子句柄

HWND g_hWndCaller = NULL;

HHOOK g_hHook = NULL;

#pragma data_seg()

 

//通过内存地址取得模块句柄

HMODULE WINAPI ModuleFromAddress(PVOID pv)

{

    MEMORY_BASIC_INFORMATION mbi;//此结构请查看MSDN

    if(::VirtualQuery(pv,&mbi,sizeof(mbi)))

    {

        return (HMODULE)mbi.AllocationBase;

    }

    return NULL;

}

 

//钩子的回调函数

LRESULT CALLBACK KeyHookProc(int nCode,//HOOK代码，钩子函数使用这个参数来确定任务

                             WPARAM wParam,

                             LPARAM lParam)

{

    if(nCode<0||nCode == HC_NOREMOVE)//没用的消息

    {

        return ::CallNextHookEx(g_hHook,nCode,wParam,lParam);

    }

    if(lParam&0x40000000)//消息重复

    {

        return ::CallNextHookEx(g_hHook,nCode,wParam,lParam);

    }

    ::PostMessage(g_hWndCaller,WM_CLOSE,0,0);

    return ::CallNextHookEx(g_hHook,nCode,wParam,lParam);

}

 

//给系统注册钩子

BOOL WINAPI SetKeyHook(BOOL bInstall,DWORD dwThreadId,HWND hWndCaller)

{

    BOOL bOK;

    g_hWndCaller = hWndCaller;

    if(bInstall)

    {

        HMODULE temp = ModuleFromAddress(KeyHookProc);//钩子函数所在的DLL的实例句柄

        g_hHook = ::SetWindowsHookEx(

            WH_KEYBOARD,//键盘钩子标志

            KeyHookProc,//回调函数

            temp,

            dwThreadId//线程句柄

            );

        if(g_hHook!=NULL)

        {

            bOK = TRUE;

        }

        else

        {

            bOK = FALSE;

        }

    }

    else

    {

        bOK = ::UnhookWindowsHookEx(g_hHook);//卸载钩子

        g_hHook = NULL;

    }

    return bOK;

}

DLL项目的DEF文件

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LIBRARY "gouzi"

EXPORTS

SetKeyHook

SECTIONS

MyShared Read Write Shared

 

注册钩子的工程

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#include <windows.h>

#include <iostream>

#include "a1.h"//DLL中的头文件

using namespace std;

#pragma comment(lib,"gouzi")

 

 

void main()

{

    ::SetConsoleTitle("aaa");

    //HWND hWnd = ::FindWindow(NULL,"Our First Window");

    HWND hWnd = ::FindWindow("notepad",NULL);

    //::SendMessage(hWnd,HM_KEY,)

    if(!SetKeyHook(TRUE,0,hWnd))

    {

        cout<<"安装钩子失败"<<endl;

        return;

    }

    char a;

    while(true)

    {

        cin>>a;

        if(a == 'u')

        {

            SetKeyHook(FALSE,0,hWnd);

            return;

        }

    }

    return;

}