我有一个更新面板,并使用PostBackTrigger事件更新进度.但是当我点击按钮时,没有显示更新进度.请找到以下示例代码
<asp:UpdateProgress ID="UpdateProgress1" runat="server" AssociatedUpdatePanelID="updatepanelDropDownTaskType" CssClass="Token-setup-popup" DynamicLayout="true">
<ProgressTemplate>
<div id="loading" class="loading">
<asp:Image runat="server" ID="imgBusyIndicator" ImageUrl="~/images/busy-indicator.gif" />
</div>
</ProgressTemplate>
</asp:UpdateProgress>
<asp:UpdatePanel ID="updatepanelDropDownTaskType" runat="server" UpdateMode="Conditional">
<Triggers>
<asp:PostBackTrigger ControlID="btnExport" />
</Triggers>
<ContentTemplate>
<asp:Button ID="btnExport" runat="server" Text="Export To CSV" CssClass="button" CausesValidation="true" onclick="btnExport_Click" ClientIDMode="Static"/></asp:Button>
</ContentTemplate>
</asp:UpdatePanel>
我的代码背后
HttpResponse Response = System.Web.HttpContext.Current.Response;
Response.ClearHeaders();
Response.AppendHeader("Content-Disposition","attachment; filename=" + FileName);
Response.ContentType = FileType;
Response.Write(content);
HttpContext.Current.ApplicationInstance.CompleteRequest();
解决方法
那么你的代码还可以.问题在于您在UpdatePanel中使用的触发器.
微软说
The
UpdateProgresscontrol renders a<div>element that is
displayed or hidden depending on whether an associatedUpdatePanel
control has caused anasynchronouspostback. For initial page
rendering and forsynchronouspostbacks,theUpdateProgress
control is not displayed.
查看有关MSDN的更多详细信息
因此,您在UpdatePanel中使用PostBackTrigger将导致同步回发,并且UpdateProgress将不会显示.
<Triggers>
<asp:PostBackTrigger ControlID="btnExport" />
// Incorrect
</Triggers>
将其更改为
<Triggers>
<asp:AsyncPostBackTrigger ControlID="btnExport" />
// Correct
</Triggers>
这将显示您的UpdateProgress并将按预期工作.
正如您在评论中提到的那样,您也在网格上执行下载.您可以使用ScriptManager注册Button.这将注册您的按钮,并在异步回发时注意下载按钮.
protected void GridView_RowDataBound(object sender,GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
Button btnExport = e.item.FindControl("btnExport") as Button;
if (btnExport != null)
{
((ScriptManager)this.Page.Master.FindControl("ID of your Script manager")).RegisterPostBackControl(downloadDocColumn);
// In Above line i assumed Script Manager is placed on Your master page.
}
}
}
希望这可以帮助…
