windows api学习笔记键盘钩子

DLL项目的头文件

#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

#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

LIBRARY	"gouzi"
EXPORTS
SetKeyHook
SECTIONS
MyShared Read Write Shared

注册钩子的工程

#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;
}