Image not show up in the last postback

[Raymond Mui]

First of all, I believe that it is not a RadControls problem, but a general AJAX case.  I have a webpage that generates an Excel file on the server, and the page uses AJAX to update the status (as it is a long process).  

The following is the (partial) codes that I use:

     Me.imgStatus.ImageUrl = "~/Images/tick.jpg"

     Me.imgStatus.AlternateText = "Done"

     Me.RadAjaxManager1.ResponseScripts.Add("window.location.href='DownloadFile.aspx';")

"Downloadfile.aspx" is another file that prompts the user to Open or Save the Excel (instead of displaying on within IE).  The following is the code-behind in Downloadfile.aspx.vb:

  Response.Clear()

  Response.ContentType = "application/x-msdownload"

  Response.AddHeader("content-disposition", "attachment;filename=WAT_ASWSalesWithGPByBrandCustomer_" & Format(Now(), "yyyyMMdd") & ".xls")

  excelFile.SaveXls(Response.OutputStream)

Now, my problem: the image "imgStatus" sometimes does not show up, and there is no Red cross on the web page.  When I right-click the location of  "imgStatus", and select "Show picture", the "Tick.jpg" loaded.

I think it is "Response.Clear()" that prohibits the displaying of "imgStatus".  To ensure that "imgStatus", i.e. the tick.jpg, shows, should I add one more post-back (thus delay the page redirection).  Is there anyway to overcome this?

[Nikolay Rusev]

Hi Raymond Mui,

I am not sure whether I understand the issue correctly, but I suggest you to try buffer the response before flush it to client. You can try using the following lines

Response.Clear()
Response.Buffer = true
Response.ContentType = "application/x-msdownload"
//your other code here

Other option you have is if you are exporting RadGrid control there is property 
<RadGrid Name>.ExportSettings.OpenInNewWindow. If it set to true it new popup window will be open to save/open exported document.

I hope you will find provided information helpful. 

Best wishes,
Nikolay
the Telerik team

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