private void addBook_Click(object sender, EventArgs e)
{
NewBookForm newBook = new NewBookForm(books);
newBook.Show();
newBook.FormClosing += HandleNewBook;
}
//新书入库菜单
private void NewBook(object sender, EventArgs e)
{
NewBookForm fnb = new NewBookForm();
fnb.MdiParent = this;
fnb.StartPosition = FormStartPosition.CenterScreen;
fnb.WindowState = FormWindowState.Maximized;
fnb.Show();
}