MFC -- 键盘全局HOOK

BOOL sethook() {
       hk = SetWindowsHookEx(WH_KEYBOARD, //hook类型，键盘hook
              KeyboardProc, //回调函数
        hM, //第三方的注入dll，全局hook使用，句柄通过主函数获取
              0);//线程id，填0表示hook所有程序
       if (hk == NULL)//如果创建失败，弹出信息框
       {
             
              return FALSE;
       }
    return TRUE;
}

HMODULE hM;
HHOOK hk;
//键盘hook的回调函数
LRESULT CALLBACK KeyboardProc(int code, WPARAM wParam, LPARAM lParam)
{
       char buf[256];
       if (wParam >= 'A' && wParam <= 'Z')
       {
              sprintf_s(buf, "%c 被按下", wParam);
              OutputDebugStringA(buf);
       }
       //钩子执行完后执行该函数
       return CallNextHookEx(hk, code, wParam, lParam);
}

BOOL APIENTRY DllMain( HMODULE hModule,
                       DWORD  ul_reason_for_call,
                       LPVOID lpReserved
                     )
{
    switch (ul_reason_for_call)
    {
    case DLL_PROCESS_ATTACH:
    {
        //dll被加载执行，初始化操作
        hM = hModule;
    }
    break;
    case DLL_THREAD_ATTACH:
    case DLL_THREAD_DETACH:
    case DLL_PROCESS_DETACH:
    {
        //dll被释放时调用
    }
        break;
    }
    return TRUE;
}

#pragma comment(lib,"hookdll.lib")

BOOL sethook();

void CkeybhookDlg::OnBnClickedHook()
{
       BOOL re = sethook();
       if (!re)//如果创建失败，弹出信息框
       {
              AfxMessageBox(L"HOOK失败");
              return;
       }
     
}