下面是代码：
#define StrNum 20
#define Type 20
#include <iostream>
#include <iomanip>
#include <string>
#include <fstream> //输入输出文件流
using namespace std;
const int Maxb=100; //最多可存储的图书
class Book
{
private:
int lab; //删除标记
int num; //图书编号
int add; //增加标记
char number[StrNum]; //编号
char bookname[StrNum]; //书名
char bookkind[Type]; //图书类型
public:
Book(){}
char getkind() //获取图书类型
{
return bookkind[Type];
}
char getname() //获取书名
{
return bookname[StrNum];
}
int getnum() //获取图书编号
{
return num;
}
int getlab() //获取删除标记
{
return lab;
}
void setname(char na[]) //设置书名
{
strcpy(bookname,na);
}
void setkind(char kin[]) //设置类型
{
strcpy(bookkind,kin);
}
void delbook() //删除图书
{
lab=1;
}
void addbook(int n,char *na,char *kin) //增加图书
{
lab=0;
num=n;
strcpy(bookname,na);
strcpy(bookkind,kin);
}
void disp() //输出图书
{
cout.flags (ios::left); //设置对齐的标志位为左
cout<<setw(15)<<num<<setw(20)<<bookname<<setw(15)<<bookkind<<endl;
}
};
class BDatabase
{
private:
int top;
Book book[Maxb]; //图书记录
public:
BDatabase() //构造函数，将book.txt读到book[]中
{
Book b;
top=-1;
fstream file("book.txt",ios::in);
while (1)
{
file.read((char *)&b,sizeof(b));
if (!file)
break;
top++;
book[top]=b;
}
file.close();
}
void clear() //全删
{
top=-1;
}
int addbook(int n,char *na,char *kin) //增加图书
{
Book *p=query(n);
if(NULL==p)
{
top++;
book[top].addbook(n,na,kin);
return 1;
}
return 0;
}
Book *query(int bookid) //查找图书
{
for(int i=0;i<=top;i++)
if(book[i].getnum()==bookid&&book[i].getlab()==0)
{
return &book[i];
}
return NULL;
}
void disp() //图书库
{
for(int i=0;i<=top;i++)
if (book[i].getlab()==0)
book[i].disp();
}
~BDatabase() //析构函数，将book[]写到book.txt中，实现文本的写入
{
fastream file("book.txt",ios::out);
for(int i=0;i<=top;i++)
if(book[i].getlab()==0)
file.write((char*)&book[i],sizeof(book[i]));
file.close();
}
void main()
{
BDatabase BookDB;
char choice;
char bname[40];
char bkind[40];
char newType[20];
int bookid;
Book *b;
while (choice!='0')
{
cout<<"\t******************************************************************\n";
cout<<" \n\n";
cout<<"\t\t\t图 书 管 理 系 统\n\n";
cout<<"\t\t\t1 新增图书记录\n";
cout<<"\t\t\t2 更改图书记录\n";
cout<<"\t\t\t3 删除图书记录\n";
cout<<"\t\t\t4 查找图书记录\n";
cout<<"\t\t\t5 显示图书记录\n";
cout<<"\t\t\t6 清空全部记录（慎用）\n";
cout<<"\t\t\t0 退出系统\n";
cout<<" \n\n";
cout<<"\t******************************************************************\n";
cout<<"请选择(1,2,3,4,5,6,0):";
cin>>choice;
switch (choice)
{
case'1':
cout<<"输入图书编号:"<<endl;
cin>>bookid;
cout<<"输入图书类型:"<<endl;
cin>>newType;
cout<<"输入图书书名:"<<endl;
cin>>bname;
BookDB.addbook(bookid,bname,newType);
break;
case'2':
cout<<"输入图书编号:"<<endl;
cin>>bookid;
b=BookDB.query(bookid);
if(b==NULL)
{
cout<<"该图书不存在"<<endl;
break;
}
cout<<"输入新的书名:"<<endl;
cin>>bname;
b->setname(bname);
cout<<"输入新的类型:"<<endl;
cin>>bkind;
b->setkind(bkind);
break;
case'3':
cout<<"读入图书编号:"<<endl;
cin>>bookid;
b=BookDB.query(bookid);
if(b==NULL)
{
cout<<"该图书不存在"<<endl;
break;
}
char tg1;
cout<<"确定要删除此记录吗?(Y/N)"<<endl;
cin>>tg1;
if(tg1!='n'&&tg1!='N')
{
b->delbook();
cout<<"已成功删除该书记录！"<<endl;
break;
}
case '4':
cout<<"读入图书编号:"<<endl;
cin>>bookid;
b=BookDB.query(bookid);
if(b==NULL)
{
cout<<"该图书不存在"<<endl;
break;
}
cout<<"图书编号 图书名称 图书类型 \n";
b->disp();
break;
case '5':
cout<<"图书编号 图书名称 图书类型 \n";
b->disp();
break;
case '6':
char tg2;
cout<<"确定要清空所有记录吗?(Y/N)"<<endl;
cin>>tg2;
if(tg2!='n'&&tg2!='N')
{
BookDB.clear();
cout<<"已成功清空记录！"<<endl;
break;
}
case '0':
break;
default:cout<<"输入错误，请从新输入(数字为0~6):";
}
}
}
