“PopupControlExtender”问题

Question

“PopupControlExtender”并不包含“GetProxyForCurrentPopup”的定义 

protected void RadioButtonList1_SelectedIndexChanged(object sender, EventArgs e)
    {
        if (RadioButtonList1.SelectedValue != null)
        {
           PopupControlExtender.GetProxyForCurrentPopup(this.Page).Commit(RadioButtonList1.SelectedValue);
          
        }
        RadioButtonList1.ClearSelection();

    }

HTML代码：

 <asp:ScriptManager ID="ScriptManager1" runat="server">
            </asp:ScriptManager>
            <br />
            <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox><br />
            <br />
               <asp:Panel ID="Panel2" CssClass="popupbox" runat="server" Height="50px" Width="125px">
                <asp:UpdatePanel ID="UpdatePanel1" runat="server">
                    <ContentTemplate>
                        <asp:RadioButtonList AutoPostBack="true" ID="RadioButtonList1" runat="server" OnSelectedIndexChanged="RadioButtonList1_SelectedIndexChanged">
                            <asp:ListItem Text="广州市"></asp:ListItem>
                            <asp:ListItem Text="佛山市"></asp:ListItem>
                            <asp:ListItem Text="深圳市"></asp:ListItem>
                            <asp:ListItem Text="东莞市"></asp:ListItem>
                        </asp:RadioButtonList>
                    </ContentTemplate>
                </asp:UpdatePanel>
            </asp:Panel>
            &nbsp;<br />
           <ajaxToolkit:PopupControlExtender ID="PopupControlExtender1" TargetControlID="TextBox1" PopupControlID="Panel1" CommitScript="e.value;" Position="Bottom" CommitProperty="value" runat="server">
</ajaxToolkit:PopupControlExtender>

Answer 1

会不会缺少程序集引用?