为什么sqldatasource有参数且有默认值时，repeater控件取不出值，具体代码如下：

<form id="form1" runat="server">
    <div>
    <ul>
        <asp:Repeater ID="Repeater1" runat="server" DataSourceID="SqlDataSource1">
            <ItemTemplate>
                <li>
                    <%#Eval("Newsnr") %>
                </li>
            </ItemTemplate>
        </asp:Repeater>
    </ul>
        <asp:SqlDataSource ID="SqlDataSource1" runat="server"
            ConnectionString="<%$ ConnectionStrings:XinxixiConnectionString %>"
            SelectCommand="SELECT [NewsID], [NewsTitle], [Newsnr], [Newsgjz], [FUsername], [Fbtime], [lanMuID], [yueDucishu], [souYetuijian] FROM [Xinxixi_News] WHERE ([lanMuID] = @lanMuID)">
            <SelectParameters>
                <asp:Parameter DefaultValue="912ba373-2305-49c4-b125-014c56b04f28"
                       Name="lanMuID" Type="Object" />
            </SelectParameters>

        </asp:SqlDataSource>
    </div>
    </form>

//当没有defaultvalue时从数据库中可以直接取出数据，看另外一种的写法
<asp:SqlDataSource ID="SqlDataSource1" runat="server"
            ConnectionString="<%$ ConnectionStrings:XinxixiConnectionString %>"
            SelectCommand="SELECT [NewsID], [NewsTitle], [Newsnr], [Newsgjz], [FUsername], [Fbtime], [lanMuID], [yueDucishu], [souYetuijian] FROM [Xinxixi_News]">
        </asp:SqlDataSource>，这种能够取出来
他们两个的区别是上面的多了一个
            <SelectParameters>
                <asp:Parameter DefaultValue="912ba373-2305-49c4-b125-014c56b04f28"
                       Name="lanMuID" Type="Object" />
            </SelectParameters>

我是一个新手，麻烦详细一点 --------------------编程问答-------------------- 加上查询条件就没有值了，没有满足条件的记录 --------------------编程问答-------------------- 把这句在数据库中执行以下应该是查询不到数据的
SELECT [NewsID], [NewsTitle], [Newsnr], [Newsgjz], [FUsername], [Fbtime], [lanMuID], [yueDucishu], [souYetuijian] FROM [Xinxixi_News] WHERE ([lanMuID] = ‘912ba373-2305-49c4-b125-014c56b04f2’)

补充：.NET技术 ,  非技术区