SqlDataSource绑定GridView问题

<asp:SqlDataSource ID="SqlDataSource1" runat="server" 

          ConnectionString="<%$ ConnectionStrings:testdbConnectionString %>" 

          

          SelectCommand="SELECT * FROM [Visitor] WHERE ((@DropDownListValues LIKE '%'+ @VisitorId + '%'))">

          <SelectParameters>

              <asp:ControlParameter ControlID="TextBox1" Name="VisitorId" PropertyName="Text" 

                  Type="String" />

              <asp:ControlParameter ControlID="DropDownList1" Name="DropDownListValues" 

                  PropertyName="SelectedValue" Type="String" />

          </SelectParameters>

      </asp:SqlDataSource>

@DropDownListValues这个使用动态就查询不到了.如果写死一切正常. --------------------编程问答-------------------- @DropDownListValues为动态的话

可能确定不了值哦！

可否换另一种绑定如果需要的话我给你写个。 --------------------编程问答-------------------- SelectCommand="SELECT [au_name], [au_id] FROM [authors] WHERE ([au_id] = @au_id)">
            <SelectParameters>
                <asp:ControlParameter ControlID="DropDownList2" Name="au_id" PropertyName="SelectedValue"
                    Type="String" />
            </SelectParameters>
@DropDownListValues 动态，后台配置 --------------------编程问答--------------------

SqlDataSource1 .SelectParameters.Add("DropDownListValues",System.TypeCode.String,DropDownList1.SelectedValue);

补充：.NET技术 ,  ASP.NET