关于多重继承的问题
无聊客 2006-03-08 08:11:59 同样的代码在VC6中能够编译通过,但是EVC4就不行,还望高手指教:
首先我创建了一个标准的MFC EXE工程,在随便加了个自定义的类:
class CTest
{
public:
CTest(){};
virtual ~CTest(){};
virtual BOOL TestOut(){return TRUE;}
};
再修改原先默认的CMainFrame定义,改以后为:
class CMainFrame : public CFrameWnd, public CTest
{
......
};
然后编译,发现VC6正常通过,但是EVC4报错,错误出现先在消息定义里:
BEGIN_MESSAGE_MAP(CMainFrame, CFrameWnd)
......
ON_NOTIFY(DLN_CE_CREATE, AFXCE_ID_DOCLIST, OnCreateDocList) //这句出错
......
END_MESSAGE_MAP()
E:\MyWork\TestEVC\MainFrm.cpp(30) : error C2440: 'type cast' : cannot convert from 'void (__thiscall CMainFrame::*)(struct tagDLNHDR *,long *)' to 'void (__thiscall CCmdTarget::*)(struct tagNMHDR *,long *)'
Pointers to members have different representations; cannot cast between them
不解,请教高手这是什么原因?谢谢!