妳可以拿去參考壹下，基本功能都已經實現了，妳可以做壹些小的修改
如有幫助謝謝采納。
//模擬超市pos機實現銷售、檢索、庫存、結算功能
#include<iostream>
#include<fstream>
#include<string>
#include<stdlib.h>
#include<iomanip>
using namespace std;
//定義產品類
class product
{
public:
void put();
void sell();
void search();
void all();
void jiesuan();
void cmd();
private:
int id;
string name;
int price;
int number;
};
//類的實現
//入庫實現
void product::put()
{
fstream infile;
infile.open("txt.txt",ios_base::out|ios_base::app);
if(!infile)
cout<<"無法打開文件"<<endl;
cout<<"請輸入商品編號"<<endl;
cin>>id;
cout<<"\n請輸入商品名稱"<<endl;
cin>>name;
cout<<"\n請輸入商品價格"<<endl;
cin>>price;
cout<<"\n請輸入商品數量"<<endl;
cin>>number;
infile<<id<<"\t"<<name<<"\t"<<price<<"\t"<<number<<"\t\n";
infile.close();
}
//顯示所有記錄
void product::all()
{
fstream infile;
infile.open("txt.txt",ios_base::in);
if(!infile)
cout<<"無法打開文件"<<endl;
cout<<'\t'<<"商品編號"<<'\t'<<"商品名稱"<<'\t'<<"商品價格"<<'\t'<<"商品數量\n";
infile>>id>>name>>price>>number;
cout<<setw(12)<<id<<setw(16)<<name<<setw(16)<<price<<setw(20)<<number;
infile.close();
}
//結算的實現
void product::jiesuan()
{
cout<<"jiesuan"<<endl;
}
//查詢商品信息
void product::search()
{ product a;
fstream infile;
infile.open("txt.txt",ios_base::in|ios_base::out);
if(!infile)
cout<<"無法打開文件"<<endl;
cout<<'\t'<<"商品編號"<<'\t'<<"商品名稱"<<'\t'<<"商品價格"<<'\t'<<"商品數量\n";
infile>>setw(8)>>id>>setw(8)>>name>>setw(3)>>price>>setw(4)>>number;
cout<<setw(12)<<id<<setw(16)<<name<<setw(16)<<price<<setw(16)<<number;
// infile>>setw(8)>>id>>setw(8)>>name>>setw(3)>>price>>setw(4)>>number;
// cout<<setw(12)<<id<<setw(16)<<name<<setw(16)<<price<<setw(20)<<number;
infile.close();
}
//銷售實現
void product::sell()
{
cout<<"sell"<<endl;
}
//查看指令
void product::cmd()
{
cout<<"a,查看庫存"<<endl;
cout<<"r,入庫操作"<<endl;
cout<<"j,結算操作"<<endl;
cout<<"z,查找商品"<<endl;
cout<<"s,銷售商品"<<endl;
cout<<"c,查看指令"<<endl;
cout<<"e,退出系統"<<endl;
}
void exit()
{
}
//主函數實現
int main()
{
product one;
char ch;
cout<<"\t*********************************************************"<<endl;
cout<<"\t*\t\t歡迎使用pos模擬系統\t\t\t*\n"<<endl;
cout<<"\t*\t\t查看指令請輸入c\t\t\t\t*"<<endl;
cout<<"\t*********************************************************"<<endl;
do{
cout<<"\n請輸入條形碼或操作指令"<<endl;
cin>>ch;
switch(ch)
{
case 'a':
one.all();//查看庫存
break;
case 'r':
one.put();//入庫
break;
case 'j':
one.jiesuan();//結算
break;
case 'z':
one.search();//查找
break;
case 's':
one.sell();//銷售
break;
case 'c':
one.cmd();//查看指令
break;
case 'e':
break;
default:
cout<<"輸入錯誤，請重新輸入！\n"<<endl;
break;
}
}while(ch!='e');
return 0;
}