rdatebase.h

这是图书管理系统的Ｃ＋＋源代码．能够完成借书

//读者类库，实现建立读者的个人资料
#include"Reader.h"
class RDatabase
{  
    private:
      int top;            //读者记录指针
      Reader read[Maxr];  //读者记录
    public:
	  RDatabase()      //构造函数，将reader.txt读到read[]中
	  {/*
		Reader s;
		top=-1;
		fstream file("reader.txt",ios::in);//打开一个输入文件
		while (1)
		{
			file.read((char *)&s,sizeof(s));
			if (!file)break;
			top++;
			read[top]=s;
		}
		file.close();     //关闭 reader.txt
		*/
	  }
     void clear()//删除所有读者信息
	 {
		top=-1;
	 }
	 int addreader(int n,char *na)//添加读者时先查找是否存在
	 {
		Reader *p=query(n);
		if (p==NULL)
		{
		  top++;
		  read[top].addreader(n,na);
		  return 1;
		}
		return 0;

	 }
	 Reader *query(int readerid)          //按编号查找
	 {
		for (int i=0;i<=top;i++)
			if (read[i].getno()==readerid && 
			read[i].gettag()==0)
			{
				return &read[i];
			}
			return NULL;
	 }
	 void disp()                           //输出所有读者信息
	 {
           for (int i=0;i<=top;i++)
			   read[i].disp();
	 }
	void readerdata();                     //读者库维护
	~RDatabase()                           //析构函数，将read[]写到reader.txt文件中
	{
		fstream file("reader.txt",ios::out);
        for (int i=0;i<=top;i++)
			if (read[i].gettag()==0)
				file.write((char *)&read[i],sizeof(read[i]));
			file.close();

	}
};
void RDatabase::readerdata()
{

    char choice;
	char rname[20];
	int readerid;
	Reader *r;
	while (choice!='0')
	{
        cout <<"\n\n\t\t\t读   者   维   护\n\n\n\t\t\t 1   新      增\n\n\t\t\t 2   更      改\n\n\t\t\t 3   删      除\n\n\t\t 4   查      找\n\n\t\t 5   显      示\n\n\t\t 6   全      删\n\n\t\t\t 0   退      出"<<endl;
		cin >> choice;
		switch (choice)
		{
            case '1':
				cout << "输入读者编号:";
				cin >> readerid;
				cout << "输入读者姓名:";
				cin >> rname;
				addreader (readerid,rname);
				break;
            case '2':
				cout << "输入读者编号:";
				cin >> readerid;
				r=query(readerid);
				if (r==NULL)
				{
					cout << " 该读者不存在  "<<endl;
				    break;
				}
				cout << "输入新的姓名:";
				cin >> rname;
				r->setname(rname);
			 	break;
            case '3':
				   	cout << " 输入读者编号:";
                    cin >> readerid;
					r=query(readerid);
					if (r==NULL)
					{
					    cout <<" 该读者不存在" << endl;
					    break;
					}
					r->delbook();
					break;
			case '4':
				cout << "读入读者编号:";
				cin >> readerid;
				r=query(readerid);
				if (r==NULL)
				{
					cout <<"该读者不存在"<< endl;
					break;
				}
				r->disp();
				break;
			case '5':
				disp();
				break;
			case '6':
				clear();
				break;
			default:cout<<"输入错误，请从新输入：";break;
		}
	}
}