错误提示：第一次可以load该页面，当dropdownlist里的值发生改变时页面就出错了．
Exception Details: System.IndexOutOfRangeException: Cannot find table 0.

Source Error:


Line 74:                     //DropDownList1.Items.Clear();
Line 75:                     //DropDownList2.Items.Clear();
Line 76:                     foreach(DataRow dr in ds.Tables[0].Rows)
Line 77:                         DropDownList1.Items.Add(dr[1].ToString());
Line 78:                         DropDownList1.SelectedValue = DropDownList1.Items[1].ToString();
 


        if(!Page.IsPostBack)
                //在下拉框加入所有在产产品以供选择
                ds = searchdate.SearchAllProduct();
                    //DropDownList1.Items.Clear();
                    //DropDownList2.Items.Clear();
                    foreach(DataRow dr in ds.Tables[0].Rows)
                        DropDownList1.Items.Add(dr[1].ToString());
                        DropDownList1.SelectedValue = DropDownList1.Items[1].ToString();
            //在下拉框加入所有在产产品以供选择
                ds = searchdate.SearchProductStation(DropDownList1.SelectedValue.Trim());
                    foreach(DataRow dr in ds.Tables[0].Rows)
                    DropDownList2.Items.Add(dr[0].ToString());

1.快速监视，看table里面的数据，没有就是前面连接有问题
2，DropDownList1.Items.Add(dr[1].ToString()); 是不是DropDownList1.Items.Add(dr.ToString()); ？

----数据库里的第二个字段读取出来，应该没有问题．

汗啊，if 下面没有{ }.解决了．．．．