SetWindowsHookEx，KeyboardProc和非静态成员 [英] SetWindowsHookEx, KeyboardProc and Non-static members

问题描述

我正在创建一个键盘钩，其中KeyboardProc是类CWidget的静态成员。

I am creating a keyboard hook, wherein KeyboardProc is a static member of a class CWidget.

class CWidget
{
   static LRESULT CALLBACK KeyboardProc(int code, WPARAM wParam, LPARAM lParam );

};

我想在CWidget :: KeyboardProc中调用CWidget的非静态成员。

I want to call the non-static members of CWidget inside the CWidget::KeyboardProc.

最好的方法是什么？

KeyboardProc没有任何32位DWORD，我可以在其中传递 this指针。

KeyboardProc does not have any 32 bit DWORD where I can pass the 'this' pointer.

推荐答案

鉴于您可能一次只想安装一个键盘钩，只需在您的班级中添加一个静态pThis成员即可：

Given that you probably only want one keyboard hook installed at a time, just add a static pThis member to your class:

// Widget.h
class CWidget
{
    static HHOOK m_hHook;
    static CWidget *m_pThis;

public:
    /* NOT static */
    bool SetKeyboardHook()
    {
        m_pThis = this;
        m_hHook = ::SetWindowsHookEx(WH_KEYBOARD, StaticKeyboardProc, /* etc */);
    }

    // Trampoline
    static LRESULT CALLBACK StaticKeyboardProc(int code, WPARAM wParam, LPARAM lParam)
    {
        ASSERT(m_pThis != NULL);
        m_pThis->KeyboardProc(code, wParam, lParam);
    }

    LRESULT KeyboardProc(int code, WPARAM wParam, LPARAM lParam);

    /* etc. */
};

您需要定义静态成员：

// Widget.cpp
CWidget *CWidget::m_pThis = NULL;

这篇关于SetWindowsHookEx，KeyboardProc和非静态成员的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！