protected void Page_Load(object sender, EventArgs e)
{
// 传参异常捕获
try
{
// 获取get的传参
BookId = Convert.ToInt32(Request.QueryString["id"]);
}
catch (Exception)
{
Response.Redirect("./Main.aspx");
}
// id值不可为负数
if (BookId <= 0)
{
Response.Redirect("./Main.aspx");
}
BookDao bookDao = new BookDao();
// 获取图书详情
BookInfo bookInfo = bookDao.GetBookDetailById(BookId);
// 展示到页面
BookAuthor = bookInfo.Author;
BookDescription = bookInfo.Description;
BookImage = bookInfo.Image;
BookPrice = bookInfo.Price;
BookTitle = bookInfo.Name;
BookType = bookInfo.TypeName;
}
private void UpdatePage()
{
int id = 0;
try
{
id = Convert.ToInt32(Request.QueryString["bookId"]);
}
//捕获异常，如果有错就返回上一页
catch (Exception)
{
Response.Write("<script>window.history.go(-1);</script>");
}
//实例化一个数据库操作
BookDao bookDao = new BookDao();
//通过ID获取书本的详细信息
BookInfo book = bookDao.GetBookDetailById(id);
if (book == null)
{
//无数据时，返回上一页
Response.Write("<script>window.history.go(-1);</script>");
}
else
{
//将这本书的信息写在界面上
TextAuthor.Text = book.Author;
TextDescription.Text = book.Description;
TextImage.Text = book.Image;
TextName.Text = book.Name;
TextPrice.Text = book.Price + "";
for (int i = 0; i < DropDownList.Items.Count; i++)
{
if (Convert.ToInt32(DropDownList.Items[i].Value) == book.TypeId)
{
DropDownList.SelectedIndex = i;
}
}
}
}