RT:页面中用SqlDataSource数据控件绑定Dropdownlist下拉框,在后台编码根据Value选定无效,方法如下:
                    ddlCustomer.SelectedIndex = ddlCustomer.Items.IndexOf(ddlCustomer.Items.FindByValue(dr["Orders_CustomerID"].ToString()));
                    OR
                    ddlCustomer.Items.FindByValue(dr["Orders_CustomerID"].ToString()).Selected = true;
后台编写程序绑定Dropdownlist的话同上方法可以;??