图书管理系统类模板

用类模板写的文件的增删改查操作。

#ifndef __FILEMA
#define __FILEMA

#include<fstream>
#include<iostream>
using namespace std;


struct bookinfo
{
    char ID[30];
    char name[30];
    char author[30];
    char publishing[30];
    double price;
    int num;
};


struct memberinfo
{
    char name[30];
    char ID[30];
    char address[30];
};

struct orderinfo
{
    char name[30];
    char ID[30];
    char address[30];
    char bookID[30];
    char bookname[30];
    double price;
    int num;
};




template<typename T,typename TT>
class myfile
{
public:
    myfile(char *temp);
    long findinfo(int cho,char *cond);
    void delectinfo(long pos);
    void findall();
    long addinfo(T temp);
    long modifyinfo(long pos);
    void outputinfo(long pos);
private:
    char filename[20];
};




template<typename T,typename TT>
myfile<T,TT>::myfile(char *temp)
{

    strcpy(filename,temp);
}


template<typename T,typename TT>
long myfile<T,TT>::findinfo(int cho,char *cond)
{
    //bookinfo temp;

    T temp;
    char tcond[30];
    fstream fbook(filename,ios::out|ios::in|ios::binary);

    strcpy(tcond,cond);



    if (!fbook)
    {
        cout<<"不能打开"<<filename<<endl;
        abort();
    }

    int ii=0;

    while (!fbook.eof())
    {

        fbook.seekp(sizeof(T)*ii);
        fbook.read((char *)&temp,sizeof(T));

        if(1 == cho)
        {
            if(0 == strcmp(temp.name,tcond))
            {
                return fbook.tellg();
            }

        }


        if(2 == cho)
        {
            if(0 == strcmp(temp.ID,tcond))
            {
                return fbook.tellg();
            }

        }

        ii++;
    }



    fbook.close();
    cout<<"没有查找到"<<endl;
    system("pause");


    return 9999;          //标志查找失败
}


template<typename T,typename TT>
void myfile<T,TT>::findall()
{

    T temp;
    fstream fbook(filename,ios::out|ios::in|ios::binary);

    if (!fbook)
    {
        cout<<"不能打开"<<filename<<endl;
        abort();
    }

    int ii=0;

    while (!fbook.eof())
    {
        TT temp2(1);


        fbook.seekp(sizeof(bookinfo)*ii);
        fbook.read((char *)&temp,sizeof(bookinfo));
        if (fbook.eof() !=0 )
        {
            break;
        }

        temp2.display(temp);
        ii++;
    }
    system("pause");
}


template<typename T,typename TT>
void myfile<T,TT>::delectinfo(long pos)
{
    fstream ftemp("temp.dat",ios::out|ios::in|ios::binary|ios::trunc);
    fstream fbook(filename,ios::out|ios::in|ios::binary);
    T temp;
    int ii=0;
    char info[50];

    while(!fbook.eof())
    {
        fbook.seekp(sizeof(T)*ii);
        fbook.read((char *)&temp,sizeof(T));

        if (pos != fbook.tellg() && !fbook.eof())
        {
            ftemp.write((char *)&temp,sizeof(T));

            TT tt(1);

            tt.display(temp);


        }
        ii++;
    }

    ftemp.close();
    fbook.close();
    system("pause");
    sprintf(info,"del %s",filename);
//  system( "del book.dat");         //删除原始文件
    system(info);
    sprintf(info,"rename temp.dat,%s",filename);
//  system( "rename temp.dat,book.dat");      //修改文件名
    system(info);
}



template<typename T,typename TT>
long myfile<T,TT>::addinfo(T temp)
{
    fstream fbook(filename,ios::out|ios::in|ios::binary|ios::app);
    fbook.seekg(0,ios::end);
    if (!fbook)
    {
        cout<<"打开"<<filename<<"出错"<<endl;
        abort();
    }

    fbook.write((char *)&temp,sizeof(T));
    fbook.close();

    return fbook.tellg();

}


template<typename T,typename TT>
long myfile<T,TT>::modifyinfo(long pos)
{
    T temp;
    fstream fbook(filename,ios::out|ios::in|ios::binary);
    TT temp2(1);


    cout<<"请输入要修改的数据"<<endl;
    temp2.setinfo();
    temp2.getstruct(temp);

    fbook.seekp(pos-sizeof(T));
    fbook.write((char *)&temp,sizeof(T));
    fbook.close();
    return pos;
}

template<typename T,typename TT>
void myfile<T,TT>::outputinfo(long pos)
{
    T temp;
    fstream fbook(filename,ios::out|ios::in|ios::binary);

    fbook.seekp(pos-sizeof(T));
    fbook.read((char *)&temp,sizeof(T));

    TT temp2(1);

    temp2.display(temp);


    fbook.close();
    system("pause");

}





#endif

 

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