bdatabase.h

来自「图书管理系统」· C头文件 代码 · 共 69 行

#include"book.h"
class BDatabase  
{  
private:  
//图书记录指针  
int top;  
//图书记录  
Book book[Maxb];  
public:  
//构造函数，将book.txt读到book[]中  
BDatabase()  
{  
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();  
}  
//全删  
void clear()  
{  
top=-1;  
}  
//增加图书  
int addbook(int n,char *na)  
{  
Book *p=query(n);  
if (NULL==p)  
{  
top++;  
book[top].addbook(n,na);  
return 1;  
}  
return 0;  
}  
//查找图书  
Book *query(int bookid)  
{  
for (int i=0;i<=top;i++)  
if (book[i].getno()==bookid &&book[i].gettag()==0)  
{  
return &book[i];  
}  
return NULL;  
}  
//图书库维护  
void bookdata();  
void disp()  
{  
for (int i=0;i<=top;i++)  
if (book[i].gettag()==0)  
book[i].disp();  
}  
//析构函数，将book[]写到book.txt文件中  
~BDatabase()  
{  
	fstream file("book.txt",ios::out);  
for (int i=0;i<=top;i++)  
if (book[i].gettag()==0)  
file.write((char *)&book[i],sizeof(book[i]));  
file.close();  
}  
};