/// <summary>
        /// 加载图书详细信息
        /// </summary>
        private void InitData()
        {
            int bookId = Convert.ToInt32(Request.QueryString["book_id"]);
            Book book = new Book();
            book.LoadData(bookId);

            Category category = new Category();
            category.LoadData(book.CategoryID);
            LabelBookInfo.Text = "【类别】" + category.CategoryName
                                + "<hr>【书名】" + book.BookName
                                + "<hr>【作者】" + book.Author
                                + "<hr>【出版社】" + book.Publisher
                                + "<hr>【出版日期】" + book.PublishDate.ToLongDateString()
                                + "<hr>【价格】¥" + book.Price.ToString()
                                + "<hr>【页数】" + book.PageNum.ToString()
                                + "<hr>【简介】" + book.Description
                                + "<hr>【销量】" + book.SaleCount.ToString() + "册";
            ImageBook.ImageUrl = "BookPics\\" + book.PictureUrl;
        }
        /// <summary>
        /// “删除”按钮单击事件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        protected void ButtonDelete_Click(object sender, EventArgs e)
        {
            ArrayList selectedBooks = this.GetSelected();
            Book book = new Book();

            //如果用户没有选择,就单击该按钮,则给出警告
            if (selectedBooks.Count == 0)
            {
                Response.Write("<Script Language=JavaScript>alert('请首先选择图书!');</Script>");
                return;
            }

            //循环将选择的图书删除
            foreach (int bookId in selectedBooks)
            {
                book.LoadData(bookId);
                book.Delete();
            }
            Query();
        }