我的文件正在输出到屏幕两次 C++

大家好，我写了一个代码，我的文件输出了一些单词两次？

这是类的方法。 我调用 in 主程序。 创建列表没问题，但显示是有问题的。

它显示一些项目两次，主要是最后一个条目的项目。

  void Books ::createList()
  {
  ofstream outfile;
    outfile.open("bookshop.txt",ios::out );

   cout << "enter the size of list" << endl;
   cin >> n;
   if (n <= 0)
   {
    cout << "invalid entry or list empty" << endl;
   }///end if.
  else
   {
    i = 1 ;
    if (i > n)
        tmp1Ptr->next = NULL;
    else
        cout << "enter value for the list" << endl;
    for(i=1; i<=n ; i++)
    {
        cin.ignore();
        cout << "enter the author" << endl;
        getline(cin , authr);
        cout <<endl << "enter the title" << endl;
        getline(cin , titl);
        cout << endl << "enter the publisher" << endl;
        getline(cin , publishr);
        cout << endl<< "enter the price" << endl;
        cin >> pric;
        cout << endl << "enter the stock position" << endl;
        cin >> stoc;
        tmp2Ptr = new Book;
        tmp2Ptr->author = authr ;
        tmp2Ptr->title = titl ;
        tmp2Ptr->publisher = publishr ;
        tmp2Ptr->price = pric ;
        tmp2Ptr->stock = stoc ;
        outfile<<tmp2Ptr->author << endl;
        outfile<<tmp2Ptr->title <<endl;
        outfile<<tmp2Ptr->publisher <<endl;
        outfile<<tmp2Ptr->price <<endl;
        outfile<<tmp2Ptr->stock <<endl;
        if (i == 1)
        {
            headPtr = tmp2Ptr;
            tmp1Ptr = headPtr ;
            tmp1Ptr->prev = NULL;
        }///end inner if
        else
        {
            tmp1Ptr->next = tmp2Ptr;
            tmp2Ptr->prev = tmp1Ptr;
            tmp1Ptr = tmp2Ptr;

        }///end inner else.

    }///end for
    tmp1Ptr->next = NULL;
    tmp1Ptr = NULL;
    tmp2Ptr = NULL;
    cout << endl;
 }
 outfile.close();
 }///end createList
  void Books ::displayDetails()
   {
   ifstream infile;
   infile.open("bookshop.txt", ios::in);

  cout << "contents of list are:" << endl;
               while (infile.good())
               {
                string priz;
               string stok;

               getline(infile,authr1);
               getline(infile,titl1);
               getline(infile,publishr1);
               getline(infile,priz);
               getline(infile,stok);


               cout<< authr1 << endl;
                cout<< titl1 << endl;
                cout<< publishr1 << endl;
                cout << priz << endl << stok << endl;

               }


               infile.close();
                }