第一次尝试创建链表

Question

首先我想说我很抱歉，很确定这个问题将是非常基本的，但这是我第一次尝试创建一个链表。

问题是当我尝试分配内存并在"nodeHead"内放置一个新的节点地址时，我得到一个错误说:

错误C2440: '=':无法从'MatchmakingAgency::Node *'转换为'Node *'

智能感知:类型为"MatchmakingAgency::Node *"的值不能分配给类型为"Node *"的实体

文件如下:

MatchmakingAgency.h -数据库类

class Node;
#include "Client.h"
#ifndef _MatchmakingAgency_H_
#define _MatchmakingAgency_H_
class MatchmakingAgency
{
private:
    Node* nodeHead;
    Node* nodeTail;
    //Node class
    class Node
    {
    private:
        Client* client;
        Node* next;
    public:
        Node();
        Node(Client*);
        Node(Client*,Node*);
    };
    //end of Node class
public:
    MatchmakingAgency();
    MatchmakingAgency(Client*);
    ~MatchmakingAgency();
    void printDatabase();
};
#endif

MatchmakingAgency.cpp

#include "MatchmakingAgency.h"
MatchmakingAgency::MatchmakingAgency(){
    nodeHead = nodeTail = NULL;
}
MatchmakingAgency::MatchmakingAgency(Client* data){
    nodeHead = new Node(data);
}
MatchmakingAgency::~MatchmakingAgency(){
}

Node.cpp

#include "MatchmakingAgency.h"
MatchmakingAgency::Node::Node(){
    next = NULL;
}
MatchmakingAgency::Node::Node(Client* data){
    client = data;
    next = NULL;
}
MatchmakingAgency::Node::Node(Client* data,Node* nextnode){
    client = data;
    next = nextnode;
}

希望你能帮我。请不要生气;)

非常感谢!

Answer 1

向前移动声明:

class Node;

从顶部到MatchmakingAgency.h文件中的MatchmakingAgency类

//class Node; << remove this
#include "Client.h"
#ifndef _MatchmakingAgency_H_
#define _MatchmakingAgency_H_
class MatchmakingAgency
{
private:
    class Node; // << move here
    Node* nodeHead;

Answer 2

看起来您必须在使用完全限定名称时保持一致:

MatchmakingAgency::Node::Node(Client* data,MatchmakingAgency::Node* nextnode){
    client = data;
    next = nextnode;
}