C++双链表程序

几个月来我一直在尝试自学编程，我已经买了大约三本书，并在YouTube上观看了大量视频，到目前为止，这些视频很棒。但是在过去的一周左右，由于链表，我被难住了！我明白了整个概念，但语法正在杀死我！我已经编写了一些非常简单的链表程序用于锻炼，但现在我正在尝试编写一个程序，其中我将一些信息从文件（申请签证的人的信息）加载到链接列表中，然后再次显示整个批次（一旦完成，我计划将其扩展到我只显示某些节点并删除某些节点的位置，但我不会详细介绍）。希望下面显示的代码不会太长，如果我能得到一些指针（没有双关语）或一些片段来帮助我理解这些东西，那就太棒了！

附注：其中一些代码来自书中的类似示例。

这是主要的（大部分）与循环加载信息（它不起作用）

 List myList;
 visa_application *visa;
 Node * pNode;
 string visa_type;//these are all the variables that i want to load from the file
 int invoice_no;
 string surname;
 string firstname;
 double contact;
 string status;
 string result; 
ifstream in;
in.open("applications.txt",ios::in);

      while (!in.eof()){     
         pNode = new Node;
         visa = new visa_application;    //allocate memory for nodes
         in >> visa-> visa_type >> visa->invoice_no >>  visa-> surname;
         in >> visa-> firstname >> visa-> contact >> visa-> status >>  visa-> result ; 
         pNode->nData = &visa;   //put some data in the node
         myList.appendNode(pNode); //add node to list
         }

这是我的类节点头文件

 class Node
{
      friend class List;
      private:
              node_data * nData;
              Node *pNext;
              Node *pPrev;
      public:
              Node  (node_data * data){nData = data;
                                    pNext = NULL;
                                   pPrev = NULL;}
             node_data * getData(){return nData;}
};

这是类列表头文件

class List
{
    private:
        Node *pHead;
        Node *pTail;
        Node  *createNode(node_data * data);
    public:
        List ();
        ~List();
        Node  *getpHead (){ return pHead;}
        Node  *getpTail (){return pTail;}
        Node  *previousNode(Node  *pNode){return pNode->pPrev;}
        Node  *nextNode (Node  *pNode){return pNode->pNext;}
        void appendNode(node_data * value);
        void insertNode(node_data * value, Node  *pAfter);
        void removeNode(Node  *pNode);
        bool isEmpty();
        void printList(); 
};
List ::List() {
    pHead=NULL;
    pTail=NULL;
}
List ::~List(){
    while (!isEmpty())   //keep on removing until the
                               //head points to NULL
        removeNode(pHead);
    cout << "List deletedn";
}
   Node * List::createNode(node_data * data){
   Node * pNode = new Node (data); //allocate memory for new node and
                                 //intialize value to data
   return pNode;  
}
   bool List ::isEmpty(){
   return pHead == NULL;
}
void List ::appendNode(node_data * value)
{
   Node * pNode = createNode(value);
   if (isEmpty()) {     //if list is empty
        pHead = pNode;        //make head point to pNode
        pNode->pPrev = NULL;
   }
   else {                    //otherwise
        pTail->pNext = pNode;  //make tail point to pNode
        pNode->pPrev = pTail;
   }
   pTail = pNode;        //tail is now pNode
   pNode->pNext = NULL;  //pNode next now points to NULL
}

void List ::insertNode(node_data * value, Node  *pAfter)
{
   Node *pNode =  createNode(value);
   pNode->pNext = pAfter->pNext;
   pNode->pPrev = pAfter;
   if (pAfter->pNext != NULL)
        pAfter->pNext->pPrev = pNode;
   else
        pTail = pNode;
   pAfter->pNext = pNode;
}
void List ::removeNode(Node  *pNode)
{
   if (pNode->pPrev == NULL)  //if removing the head
        pHead = pNode->pNext;
   else
        pNode->pPrev->pNext = pNode->pNext;  //if removing a middle node
   if (pNode->pNext == NULL)  //if removing the tail
        pTail = pNode->pPrev;
   else
        pNode->pNext->pPrev = pNode->pPrev;
   pNode = NULL;
   delete pNode;  //*free the memory
}
void List ::printList()
{
   Node  *pNode=pHead;
   if (isEmpty())
        cout << "The list is emptyn";
   else
        for (pNode = pHead; pNode != NULL; pNode = pNode->pNext)
            pNode->nData->print();
}

我的类签证申请头文件

class visa_application
{
public:
    // class constructor
    visa_application();
    // class destructor
    ~visa_application();

private:
     string visa_type;
     int invoice_no;
     string surname;
     string firstname;
     double contact;
     string status;
     string result;     
};

最后是签证申请.cpp

     visa_application::visa_application()
{
     string visa_type = none;
         int invoice_no = 0;
         string surname = none;
         string firstname = none;
         double contact = 00;
         string status = none;
         string result = none; 
 }
 class destructor
 visa_application::~visa_application()
{
// insert your code here
}  

我收到错误"调用'列表：：appendNode（Node*&）'没有匹配函数"以及其他一些事情。无论如何，我知道这很长，但如果我能得到一些帮助，那就太好了，我没有导师或老师或类似的人来帮助我，所以任何反馈将不胜感激！谢谢！

**编辑错误消息是：

 no matching function for call to `Node::Node()' 
 candidates are: Node::Node(const Node&) 
 Node::Node(node_data*)     
 no matching function for call to `List::appendNode(Node*&)' 
 candidates are: void List::appendNode(node_data*)