5

我正在尝试使用我的列表视图的下拉列表过滤结果。

我已按如下方式更改了数据源的选择查询...

列表视图:

<asp:AccessDataSource ID="AccessDataSource1" runat="server" 
        DataFile="~/App_Data/ASPNetDB.mdb" 
        SelectCommand="SELECT * FROM [tblNames] WHERE Surnames=@Surnames">
        <SelectParameters>
            <asp:ControlParameter ControlID="DropDownList1" Name="Surnames" 
                PropertyName="SelectedValue" />
        </SelectParameters>
    </asp:AccessDataSource>

下拉列表:

<asp:DropDownList ID="DropDownList1" runat="server" 
        DataSourceID="AccessDataSource2" DataTextField="Genre" 
        DataValueField="NameID" AppendDataBoundItems="true">
            <asp:ListItem Value="" Selected ="True" >All Surnames</asp:ListItem>
</asp:DropDownList>

    <asp:AccessDataSource ID="AccessDataSource2" runat="server" 
        DataFile="~/App_Data/ASPNetDB.mdb" SelectCommand="SELECT * FROM [tblSurnames]">
    </asp:AccessDataSource>

使用了正确的控件名称(也使用了完全相同的大写字母),但加载页面返回在 ControlParameter 'Surnames' 中找不到控件 'DropDownList1'。

关于我在这里做错了什么有什么建议吗?

编辑:如果有帮助,这是堆栈跟踪

[InvalidOperationException: Could not find control 'DropDownList1' in ControlParameter 'Surname'.]
   System.Web.UI.WebControls.ControlParameter.Evaluate(HttpContext context, Control control) +2107838
   System.Web.UI.WebControls.Parameter.UpdateValue(HttpContext context, Control control) +50
   System.Web.UI.WebControls.ParameterCollection.UpdateValues(HttpContext context, Control control) +113
   System.Web.UI.WebControls.SqlDataSource.LoadCompleteEventHandler(Object sender, EventArgs e) +46
   System.EventHandler.Invoke(Object sender, EventArgs e) +0
   System.Web.UI.Page.OnLoadComplete(EventArgs e) +9010786
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2350
4

2 回答 2

8

需要以包含 DropDownList的ControlIDID 为前缀:ContentPlaceHolder

<asp:ControlParameter 
   Name="Surnames" 
   ControlID="ContentPlaceholderID$DropDownList1" 
   PropertyName="SelectedValue" 
/>

另请参阅:https ://stackoverflow.com/a/5719348/124386

于 2012-11-29T17:41:49.927 回答
0

此外,请确保您的利益控制具有 runat="server"。啊。

于 2017-07-10T19:07:25.090 回答