Question

我想设置一个全局钩子，我在从我创建的dll中获取钩子过程的地址时遇到问题。

我已经在stackoverflow上读到这个问题可能是由名称错误造成的。为了消除这个问题，你必须使用extern "C"将导出函数包装在未来的dll中，我这样做了。但是，这没有帮助。

这是我的计划：

Main.cpp的

int APIENTRY wWinMain(_In_ HINSTANCE hInstance,
                     _In_opt_ HINSTANCE hPrevInstance,
                     _In_ LPWSTR    lpCmdLine,
                     _In_ int       nCmdShow)
{
    HHOOK hHookKeyboard;
    HINSTANCE keyboardProcDLL;
    HOOKPROC hookProcKeyboard;

    keyboardProcDLL = LoadLibrary(L"C:/PV_KeyboardDLL.dll");
    if (keyboardProcDLL == NULL)
    {
        MessageBox(NULL, L"Could not load library!", L"Error", MB_ICONERROR);
        return -1;
    }

    hookProcKeyboard = (HOOKPROC)GetProcAddress(keyboardProcDLL, "PV_KeyboardProc");
    if (hHookKeyboard == NULL)
    {
        MessageBox(NULL, L"Could not load function from library!", L"Error", MB_ICONERROR);
        return -1;
    }

    hHookKeyboard = SetWindowsHookEx(WH_KEYBOARD_LL, hookProcKeyboard, keyboardProcDLL, 0);

    while (1)
    {

    }

    return 0;
}

PV_KeyboardDLL.cpp

bool toggleOnOff = false; // off by default


template<typename Type>
inline bool highOrderBit(Type value)
{
    return (value & (1 << sizeof(Type) * 8 - 1));
}

template<typename Type>
inline bool lowOrderBit(Type value)
{
    return (value & 1);
}

extern "C"
{
    __declspec(dllexport) LRESULT CALLBACK PV_KeyboardProc(int nCode, WPARAM wParam, LPARAM lParam)
    {
        // process event
        if (nCode < 0)  // do not process message 
        {
            return CallNextHookEx(NULL, nCode, wParam, lParam);
        }

        if (wParam != WM_KEYDOWN)
        {
            return CallNextHookEx(NULL, nCode, wParam, lParam);
        }

        KBDLLHOOKSTRUCT* KeyBoardHookStruct = reinterpret_cast<KBDLLHOOKSTRUCT*>(lParam);

        DWORD keyCode = KeyBoardHookStruct->vkCode;

        bool ctrlDown, altDown;

        // high-order is 1 - DOWN
        ctrlDown = highOrderBit(GetKeyState(VK_LCONTROL));
        altDown = highOrderBit(GetKeyState(VK_MENU));

        // ctrl + alt + 1(key down)
        if (ctrlDown && altDown && (keyCode == 0x31))
        {
            // toggle bool
            MessageBox(NULL, L"Workin", L"Ok", MB_OK);

            toggleOnOff = !toggleOnOff;
        }

        return CallNextHookEx(NULL, nCode, wParam, lParam);
    }

    __declspec(dllexport) bool onOrOff()
    {
        return toggleOnOff;
    }
}

我可以加载dll，但在致电GetProcAddress()后，hookProcKeyboard为NULL。

我是WINAPI的新手，我有点卡住，所以非常感谢帮助，谢谢。

Answer 1

在这里看起来像一个小的（但很重要！）拼写错误：

hookProcKeyboard = (HOOKPROC)GetProcAddress(keyboardProcDLL, "PV_KeyboardProc");
if (hHookKeyboard == NULL)
{
    MessageBox(NULL, L"Could not load function from library!", L"Error", MB_ICONERROR);
    return -1;
}

您正在调用GetProcAddress（）来填充hookProcKeyboard，然后检查hHookKeyboard的值。 hookProcKeyboard肯定是NULL！

解决这个问题，你应该更接近解决问题......

GetProcAddress无法正常工作

1 个答案: