C ++类 - 派生类中的构造函数声明

时间:2008-12-22 14:19:52

标签: c++ class constructor derived

Socket有一个构造函数,它将winsock SOCKET作为参数并将其存储在私有变量中:

Socket::Socket(SOCKET s) {
    this->s = s;
}

我正在尝试创建一个“GameSocket”类来解析来自我的Socket类的数据:

class GameSocket : public Socket {

protected:

    void ParseData(unsigned char* data, int size);

};

在这些类的旁边,我有一个“Server”类,可以在需要时创建新的套接字:

GameSocket* Server::Accept() {

    SOCKET a = accept(s, 0, 0);
    if(a==SOCKET_ERROR) {
        return 0;
    }
    else {
        return new GameSocket(a);
    }

}

然而,这给了我最后一个“其他”的错误:

error C2664: 'GameSocket::GameSocket' : cannot convert parameter 1 from 'SOCKET' to 'const GameSocket &'

在处理派生类时,我必须遗漏构造函数...

不要对我太过刻意,我对C ++和OOP相对较新

2 个答案:

答案 0 :(得分:6)

添加GameSocket的构造函数

class GameSocket : public Socket {

public:

    // you need to add
    GameSocket(SOCKET s) : Socket(s) {}

protected:

    void ParseData(unsigned char* data, int size);

};

答案 1 :(得分:2)

GameSocket的construcotr必须接收SOCKET参数,然后将其传递给初始化列表中的Socket基类:

class GameSocket : public Socket {
public:
    GameSocket(SOCKET s) : Socket(s) {}
    ...
};

为什么GameSocket必须从Socket派生而不是持有对Socket的引用? GameSocket是(或应该)管理套接字状态和序列化,而低级套接字接口包含在Socket类中。您的Server类可以创建Socket类的实例,然后将指针传递给GameSocket类来管理它们。

class GameSocket {
public:
    GameSocket(Socket *s) : s_(s) {}
    ~GameSocket() {
        s_->close();
        delete s_;
    }
    ...
private:
    Socket *s_;
};

GameSocket* Server::Accept() {
    // accept function added to Socket class
    Socket *newSocket = serverSocket->accept();
    // create GameSocket with newly opened Socket
    return newSocket ? new GameSocket(newSocket) : NULL;
}