强制调用基类虚函数

Question

我有一些像这样的事件

class Granpa // this would not be changed, as its in a dll and not written by me
{
public:

   virtual void onLoad(){}

}

class Father :public Granpa // my modification on Granpa
{
public:

    virtual void onLoad()
    {
       // do important stuff
    }

}

class Child :public Father// client will derive Father
{

   virtual void onLoad()
   {
       // Father::onLoad(); // i'm trying do this without client explicitly writing the call

       // clients code
   }
}

有没有办法强制调用onLoad而不实际编写Father :: onLoad()？

哈希解决方案是受欢迎的:)

Answer 1

如果我理解正确,你需要它,以便每当调用overriden函数时,必须始终首先调用基类实现.在这种情况下,您可以调查模板模式.就像是:

class Base
{
public:
    void foo() {
        baseStuff();
        derivedStuff();
    }

protected:
    virtual void derivedStuff() = 0;
private:
    void baseStuff() { ... }
};

class Derived : public Base {
protected:
    virtual void derivedStuff() {
        // This will always get called after baseStuff()
        ...
    }
};