dropdownlist取值问题，求教！谢谢
我从图书列表编辑那里转到编辑页面，其中有两个值是显示在下拉列表的，但是只有第一个正确显示，第二个就只显示第一行了，为什么，求助指导，谢谢了
设计界面：有两个dropdownlist控件，分别图书编辑传递过来的值，图书分类和出版社
所属丛书分类：<asp:DropDownList ID="BookTypeDDList" runat="server" ></asp:DropDownList><br /><br />
图书出版社：<asp:DropDownList ID="PublishDDList" runat="server"></asp:DropDownList><br /> <br />
后台代码如下：
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
DDListBind();//绑定下拉列表
int Id = Convert.ToInt32(Request.QueryString["BookId"]);
SqlConnection BookConn = new SqlConnection();
BookConn.ConnectionString = ConfigurationManager.ConnectionStrings["conn"].ToString();
BookConn.Open();
SqlCommand BookCmd = new SqlCommand("select * from Books where Id =" + "'" + Id + "'", BookConn);
SqlDataAdapter BookDataAdapter = new SqlDataAdapter(BookCmd);
DataSet BookDataSet = new DataSet();
BookDataAdapter.Fill(BookDataSet, "BookTable");
BookConn.Close();
this.txtId.Text = BookDataSet.Tables["BookTable"].Rows[0][0].ToString();
this.txtTitle.Text = BookDataSet.Tables["BookTable"].Rows[0][1].ToString();
this.txtAuthor.Text = BookDataSet.Tables["BookTable"].Rows[0][2].ToString();
this.PublishDDList.SelectedValue = BookDataSet.Tables["BookTable"].Rows[0][3].ToString();
this.txtPubdate.Text = BookDataSet.Tables["BookTable"].Rows[0][4].ToString();
this.txtISBN.Text = BookDataSet.Tables["BookTable"].Rows[0][5].ToString();
this.txtWordCount.Text = BookDataSet.Tables["BookTable"].Rows[0][6].ToString();
this.txtUnitePrice.Text = BookDataSet.Tables["BookTable"].Rows[0][7].ToString();
this.txtBookInfo.Text = BookDataSet.Tables["BookTable"].Rows[0][8].ToString();
this.txtAuthorDesc.Text = BookDataSet.Tables["BookTable"].Rows[0][9].ToString();
this.BookTypeDDList.SelectedValue = BookDataSet.Tables["BookTable"].Rows[0][12].ToString();
}
}
private void DDListBind()//从数据库中取得数据源，绑定到下拉列表方法
{
//新建一个连接实例
SqlConnection DDLConn = new SqlConnection();
//从Web.config文件获取数据库连接字符串
DDLConn.ConnectionString = ConfigurationManager.ConnectionStrings["conn"].ToString();
DDLConn.Open();
SqlCommand CategoryCmd = new SqlCommand("SELECT * FROM Categories", DDLConn);
SqlDataAdapter CategoryDataAdapter = new SqlDataAdapter(CategoryCmd);
SqlCommand Publishcmd = new SqlCommand("SELECT * FROM Publishers", DDLConn);
SqlDataAdapter PublishDataAdapter = new SqlDataAdapter(Publishcmd);
DataSet DDLDataSet = new DataSet();
CategoryDataAdapter.Fill(DDLDataSet, "CategoriesTable");
PublishDataAdapter.Fill(DDLDataSet, "PublisherTable");
this.BookTypeDDList.DataTextField = "Name";
this.BookTypeDDList.DataValueField = "Id";
this.BookTypeDDList.DataSource = DDLDataSet.Tables["CategoriesTable"];
this.BookTypeDDList.DataBind();
this.BookTypeDDList.Items.Insert(0, new ListItem("==请选择分类==", "全部"));
this.PublishDDList.DataTextField = "Id";
this.PublishDDList.DataTextField = "Name";
this.PublishDDList.DataSource = DDLDataSet.Tables["PublisherTable"];
this.PublishDDList.DataBind();
this.PublishDDList.Items.Insert(0, new ListItem("==请选择分类==", "全部"));
//关闭数据库连接
DDLConn.Close();
}
protected void btnEdit_Click(object sender, EventArgs e)//实现编辑更新功能
{
string BookUpdateSQL = "UPDATE Books SET ISBN=";
BookUpdateSQL = BookUpdateSQL + "'" + this.txtISBN.Text.Trim() + "',";
BookUpdateSQL = BookUpdateSQL + "Title='" + this.txtTitle.Text.Trim() + "',";
BookUpdateSQL = BookUpdateSQL + "Author='" + this.txtAuthor.Text.Trim() + "',";
BookUpdateSQL = BookUpdateSQL + "ContentDescription='" + this.txtBookInfo.Text.Trim() + "',";
BookUpdateSQL = BookUpdateSQL + "CategoryId='" + this.BookTypeDDList.SelectedValue + "',";
BookUpdateSQL = BookUpdateSQL + "UnitPrice='" + this.txtUnitePrice.Text.Trim() + "',";
BookUpdateSQL = BookUpdateSQL + "PublisherId='" +this.PublishDDList.SelectedValue + "',";
BookUpdateSQL = BookUpdateSQL + "PublishDate='" + this.txtPubdate.Text.Trim() + "'";
BookUpdateSQL = BookUpdateSQL + "WHERE Id='" + Request.QueryString["BookId"] + "'";
SqlConnection BookUpdateConn = new SqlConnection();
BookUpdateConn.ConnectionString =
ConfigurationManager.ConnectionStrings["conn"].ToString();
BookUpdateConn.Open();
//执行UPDATE语句
SqlCommand BookUpdateCmd = new SqlCommand(BookUpdateSQL, BookUpdateConn);
BookUpdateCmd.ExecuteNonQuery();
//关闭数据库连接
BookUpdateConn.Close();
//显示更新成功对话框，并链接到ClassManage.aspx网页
Response.Write("<script language='javascript'>alert('更新成功');location.href='./BookList.aspx';</script>");
}
[解决办法]
看看你的ds里面是否有数据，另外还不是很明白LZ描述的意思，LZ是不是想说第二个下拉框里面没值，
SqlConnection BookConn = new SqlConnection();
这个可以把他定义出来后面直接用就可以了就不用每次去new了。
[解决办法]
this.PublishDDList.DataTextField = "Id";
this.PublishDDList.DataTextField = "Name";
PublishDDList的text绑定了两个值......
