为什么指向虚成员函数的成员函数指针变量会有问题？
不才遇到一个看起来不应该有问题的问题，还请各位高人多多指教。
以下代码是从MSDN上拷下来并修改之后的，原始的代码是把函数指针bfnPrint放在Base类的外部定义的，就没有问题。我现在把bfnPrint定义在Base类的内部，使之成为一个成员变量，就出错了。编译后（Code::Block）在39行报以下错误：
error: 'bfnPrint' was not declared in this scope
请教各位大牛为什么会这样？要怎么实现用成员函数指针指向类的一个虚成员函数？谢谢！
//===============================================
class Base
{
public:
Base();
virtual void Print();
void (Base ::* bfnPrint)();
};
Base :: Base() : bfnPrint(&Base :: Print)
{
}
void Base :: Print()
{
cout << "Print function for class Base\n";
}
class Derived : public Base
{
public:
void Print(); // Print is still a virtual function.
};
void Derived :: Print()
{
cout << "Print function for class Derived\n";
}
int main()
{
Base *bPtr;
Base bObject;
Derived dObject;
bPtr = &bObject; // Set pointer to address of bObject.
(bPtr->*bfnPrint)();
bPtr = &dObject; // Set pointer to address of dObject.
(bPtr->*bfnPrint)();
return 0;
}
//===============================================
