4
AssociatedUpdatePanelId를 할당하면 상태를 선택하면 진행률이 표시되지 않지만 비워두면 진행률이 표시됩니다. UpdateProgress 컨트롤을 가능하게 구현이 호출 제어를위한 컨트롤 계층 구조를 검색하기 때문에,AssociatedUpdatePanelId가 설정된 경우 Update Progress가 실행되지 않는 이유는 무엇입니까?
<div>
<asp:ListBox ID="lstStates" runat="server" AutoPostBack="True"
OnSelectedIndexChanged="lstStates_SelectedIndexChanged" SelectionMode="Multiple">
</asp:ListBox>
</div>
<div>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:Panel ID="pnlCounty" runat="server">
<asp:ListBox ID="lstCounties" runat="server" SelectionMode="Multiple">
</asp:ListBox>
</asp:Panel>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="lstStates" EventName="SelectedIndexChanged" />
</Triggers>
</asp:UpdatePanel>
<asp:UpdateProgress ID="UpdateProgress2" runat="server" DisplayAfter="1"
AssociatedUpdatePanelID="UpdatePanel1">
<ProgressTemplate>
<img src="../images/loader2.gif" />
Loading Counties...
</ProgressTemplate>
</asp:UpdateProgress>
</div>