[Solved] Download files in async postback

[S]

Hi All,

I have a radgrid with a gridbuttoncolumn that l use to let users download excel files.

Its straight-forward:

 

<telerik:GridButtonColumn HeaderText="Download" Text="Get Report"
                                UniqueName="dldReportColumn" CommandName="PullReport">
                            </telerik:GridButtonColumn>

On the click event, I am trying to send the generated file, but its giving a wierd error: 

Sys.WebForms.PageRequestManagerParserErrorException

The closest scenario I have found here is:
http://www.telerik.com/community/forums/aspnet-ajax/grid/target-for-gridbuttoncolumn.aspx

But thats not the solution I want. In my earlier project, we used to be able to send the file directly to the user using Response.Write() and IE would open a dialog asking users to Open, Save or Cancel the file...

How do I achieve the file download ability using teleric:GridButtonColumn?

My code for the command handler is:

Protected Sub BatchGrid_ItemCommand(ByVal source As Object, ByVal e As Telerik.Web.UI.GridCommandEventArgs) Handles BatchGrid.ItemCommand
        If e.CommandName = "PullReport" Then
            Dim chosen As GridDataItem = DirectCast(e.Item, GridDataItem)
            Dim folder As String = chosen("folder").Text
            Dim file As String = chosen("file").Text

            'The first task is to ensure that the file exists.
            Dim fullPath As String = Path.Combine(folder, file)
            Dim fi As FileInfo = New FileInfo(fullPath)
            If fi.Exists() Then
                Dim id As String = chosen("BatchID").Text

                Response.ClearContent()
                Response.AddHeader("Content-disposition", "attachment; filename=" & file)
                Response.AddHeader("Content-Length", fi.Length)
                Response.ContentType = "application/octet-stream"
                Response.TransmitFile(fullPath)
                Response.Flush()
                Response.End()
            End If
        End If
    End Sub

This is a common scenario ... how do I get the download functionality?

[BaiH]

I think you are missing the fact that actually xHttpRequest object cannot handle file streaming. So you must disable the Ajax before hitting the server for the download. You can check this article for a possible implementation.

--BH

[Princy]

Hello,

Refer to the following help document which you may find helpful to achieve your requirement:
AJAX And File Upload

Also check out the following forum link which discusses on a similar issue:
AJAX and File Download

Hope this helps...
-Princy.

[S]

Thanks BH.

I had not seen that link.

[S]

Thanks Princy. I found that link and implemented it....