谁能给我看看有什么问题
string strConn = System.Configuration.ConfigurationManager.AppSettings[ "BuildMaterialConnectionStr "];
SqlConnection conn = new SqlConnection(strConn);
SqlDataAdapter ada = new SqlDataAdapter( "SELECT ' " + DropDownList1.SelectedItem.Text + " ',city_Id FROM city_Province ", conn);

DataSet ds = new DataSet();
ada.Fill(ds);

this.DropDownList2.DataSource = ds;
this.DropDownList2.DataTextField = this.DropDownList1.SelectedItem.Text;
this.DropDownList2.DataValueField = "city_Id ";
this.DropDownList2.DataBind();

最后出问题在 this.DropDownList2.DataValueField = "city_Id ";说是找不到 "DropDownList1.SelectedItem.Text "


[解决办法]
SqlDataAdapter ada = new SqlDataAdapter( "SELECT " + DropDownList1.SelectedItem.Text + ",city_Id FROM city_Province ", conn);
如果 DropDownList1.SelectedItem.Text 是数据库里的字段名 就不在外面加 ' '