求教一个有关c++文件输入输出的问题
最近我编写了一个同学录的程序
在测试其中文件的存取函数时发现了一个问题，就是虽然程序在编译时不出错误，也能运行，但是运行的结果却不正确，从文件读出的数据都是一些乱码，在这里我附上程序的代码，希望各位高人给予解答，十分感谢！！！！！
#include <iostream>
#include <string>
#include <iomanip>
#include <fstream>
using namespace std;
class Data //定义数据基类
{
public:
Data(){};
virtual int Compare(Data *)=0;
virtual void Show()=0;
virtual ~Data(){};
};
class Node //定义节点基类
{
private:
Data * sdata;
Node * snext;
public:
Node(){sdata=NULL;snext=NULL;}
Node(Node &node)
{
sdata=node.sdata;
snext=node.snext;
}
void InputData(Data *sdata1) {sdata=sdata1;}
void ShowNode() {sdata-> Show();}
Data *GetData() {return sdata;}
friend class List;
friend void StoreFile(List &);
};
class List //定义链表基类
{
Node *head;
public:
List();
~List(){DeleteList();}
void AddNode(Node *snode);
Node *DeleteNode(Node *);
Node *LookUp(Data &);
void ShowList();
void DeleteList();
Node *GetListHead(){return head;}
Node *GetNextNode(Node *snode) {return snode-> snext;}
};
List::List()
{
Node *p;
p=new Node;
p-> snext=p;
head=p;
}
void List::AddNode(Node *snode)
{
Node *q,*temp;
Data *p=snode-> sdata;
q=head-> snext;
temp=head;
while((q!=head)&&(p-> Compare(q-> sdata))==(1))
{
temp=q;
q=q-> snext;
}
snode-> snext=q;
temp-> snext=snode;
}
Node *List::DeleteNode(Node * snode)
{
Node *p1,*p2;
p1=head-> snext;
p2=head;
while(p1!=snode)
{
p2=p1;
p1=p1-> snext;
}
p2-> snext=p1-> snext;
return snode;
}
Node * List::LookUp(Data & data)
{
Node *p=head-> snext;
Data *q=& data;
while(p!=head)
{
if(p-> sdata-> Compare(q)==0)
return p;
p=p-> snext;
}
return 0;
}
void List::ShowList()
{
Node *p=head;
while(p-> snext!=head)
{
p=p-> snext;
(p-> sdata)-> Show();
}
}
void List::DeleteList()
{
Node *p1,*p2;
p1=head-> snext;
while(p1!=head)
{
delete p1-> sdata;
p2=p1;
p1=p1-> snext;
delete p2;
}
}
class StudentRecord:public Data
{
private:
string Name;
string Phone;
string Address;
public:
StudentRecord() {Name= "\0 ";Phone= "\0 ";Address= "\0 ";}
StudentRecord(string n,string p,string a):Name(n),Phone(p),Address(a){}
void SetRecord(string n,string p,string a)
{
Name=n; Phone=p; Address=a;
}
int Compare(Data *);
void Show();
};
int StudentRecord::Compare(Data * data)
{
StudentRecord *temp=(StudentRecord *)data;
if(Name <temp-> Name) return -1;
if(Name==temp-> Name) return 0;
if(Name> temp-> Name) return 1;
}
void StudentRecord::Show()
{
cout < <setw(15) < <Name < <setw(15) < <Phone < <setw(15) < <Address < <endl;
}
void AddRecord(List &);
void Display(List &);
void LookUp(List &);
void Delete(List &);
void StoreFile(List &);
void Operate(int,List &);
void LoadFile(List &);
int main()
{
List Student;
LoadFile(Student);
cout < < " 欢迎进入同学录数据系统 " < <endl;
int choice;
do
{
cout < < "1. 添加同学录记录. " < <endl;
cout < < "2. 显示全部记录. " < <endl;
cout < < "3. 根据姓名删除数据. " < <endl;
cout < < "4. 根据姓名查询数据. " < <endl;
cout < < "0. 退出系统. " < <endl;
cout < < "请输入您的选择: ";
cin> > choice;
Operate(choice,Student);
}while(choice!=0);
return 0;
}
void Operate(int x,List & Student)
{
switch(x)
{
case 1: AddRecord(Student);break;
case 2: Display(Student);break;
case 3: Delete(Student);break;
case 4: LookUp(Student);break;
case 0: StoreFile(Student);break;
}
}
void AddRecord(List & Student)
{
Node * snode;
StudentRecord * stu;
string Name,Phone,Address;
cout < < "请输入姓名: ";
cin> > Name;
while(Name!= "0 ")
{
cout < < "请输入电话和地址: " < <endl;
cin> > Phone> > Address;
stu=new StudentRecord;
stu-> SetRecord(Name,Phone,Address);
snode=new Node;
snode-> InputData(stu);
Student.AddNode(snode);
cout < < "请输入姓名: ";
cin> > Name;
}
cout < <endl;
}
void Display(List & Student)
{
cout < <setw(15) < < "姓名 " < <setw(15) < < "电话号码 " < <setw(15) < < "地址 " < <endl;
Student.ShowList();
cout < <endl;
}
void Delete(List & Student)
{
Node * look;
string name;
cout < < "请输入您想要删除的姓名(0结束) ";
cin> > name;
while(name!= "0 ")
{
StudentRecord stu(name, "0 ", "0 ");
look=Student.LookUp(stu);
if(look)
{
cout < < "在同学录中找到: " < <name < < ",内容是: " < <endl;
look-> ShowNode();
Student.DeleteNode(look);
cout < <name < < "的资料已删除 " < <endl;
delete look;
}
else
cout < < "在同学录中找不到 " < <name < < "! " < <endl;
cout < < "请输入您想要删除的姓名(0结束) ";
cin> > name;
}
cout < <endl;
}
void LookUp(List & Student)
{
Node * look;
string Name;
cout < < "请输入您需要查找的姓名(0结束) ";
cin> > Name;
while(Name!= "0 ")
{
StudentRecord stu(Name, "0 ", "0 ");
look=Student.LookUp(stu);
if(look)
{
cout < < "在同学录中找到: " < <Name < < ",内容是: " < <endl;
look-> ShowNode();
}
else
cout < < "在同学录中找不到 " < <Name < < "! " < <endl;
cout < < "请输入您要查找的姓名(0结束): ";
cin> > Name;
}
cout < <endl;
}
void StoreFile(List & Student)
{
string file= "STUDENT.DAT "; //设定存储的文件名
ofstream outfile(file.c_str(),ios::binary); //将文件名转成c的格式
if(!outfile)
{
cout < < "数据文件打开错误! " < <endl;
return;
}
Node * node;
StudentRecord * stu;
node=Student.GetListHead()-> snext;
while(node!=Student.GetListHead())
{
stu=(StudentRecord *)node-> GetData(); //stu为指向学生数据派生类的指针
outfile.write((char *)stu,sizeof(StudentRecord)); //将数据存入文件
node=Student.GetNextNode(node); //指向下一节点
}
outfile.close();
}
void LoadFile(List & Student)
{
string file= "STUDENT.DAT ";
ifstream infile(file.c_str(),ios::binary);
if(!infile)
{
cout < < "没有数据文件! ";
return;
}
Node * node;
StudentRecord * stu;
while(!infile.eof())
{
stu=new StudentRecord;
infile.read((char *)stu,sizeof(StudentRecord)); //从文件将数据读入学生数据类
node=new Node;
node-> InputData(stu); //将学生数据加入节点
Student.AddNode(node); //将节点加入链表
}
infile.close();
}
就是最后的两个函数有问题，但我实在找不出来了，谢谢各位大哥了，帮帮忙吧~~~~
[解决办法]
我看了下你的程序，不知道你这个程序那里有读写文件的入口了
stu=new StudentRecord;
infile.read(&stu,sizeof(StudentRecord)); //从文件将数据读入学生数据类,你把stu char了，大概是这里的原因吧，把地址给它试试
//(StudentRecord)不行加它
node=new Node;
node-> InputData(stu); //将学生数据加入节点
Student.AddNode(node); //将节点加入链表
[解决办法]
我也晕了，不过涉及文件操作的操作，如果出现乱码，而又感觉自己的程序没有啥问题，可看一下是否考虑到了字符串的结束符（如果没有，一般会乱码），另外删除或写数据时，看一下前后操作的行是否字节数一样，不然也可能会造成乱码，呵呵，我只是瞎说的
