在asp.net中下载Excelfile时等待进度条？

Question

我从主页面菜单项调用.ashx文件下载excel文件。但这里混淆了用户。用户不知道下载是否发生。

如何在主页中点击菜单项时弹出进度条，下载后自动消失？

MasterPage.Master

if e.Item.Text = "Download" Then
   Dim strUrl As String = "../Users/Download.ashx"
   ResponseHelper.Redirect(strUrl, "_black", "resizable=no, scrollbars=no")
end if

Download.ashx

Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
     'Some logic
     Dim filename As String = "FullExtract_" & Now.Year.ToString & Now.Month.ToString & Now.Day.ToString & ".xlsx"
     context.Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
     context.Response.AddHeader("content-disposition", "attachment;  filename=" & filename)
     context.Response.BinaryWrite(pck.GetAsByteArray())
     context.Response.End()
 End Sub

Answer 1

如果它不会干扰任何现有限制，您可以在页面中使用jQuery's .ajax()函数进行ajax调用并在该调用中处理客户端通知（粗略示例）：

// Notify the user about downloading.

// Perform the download
$.ajax({
    type: "POST",
    url: '/Users/Download.ashx',
    success: function(data) {
        // Notify the user it's done.
    }
});

Answer 2

您可以从 here

获得这个想法