使用vc简单实现图书的管理如借书，还书，更新，管理员登录，会员登录的功能,可以作为一个入门，对刚接触c并有兴趣的同学.-Using VC to achieve a simple library management such as library, but also books, update, the administrator login, login function, can be used as a primer, just contact C and interested stude