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CrossPagePostBack fails if postback button initially disable.

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AsyncUpload

This is a migrated thread and some comments may be shown as answers.

K asked on 04 Jan 2011, 08:14 PM

Hello,

I've encountered an odd problem attempting to use the "PostBackUrl" property of the button used to send the postback which causes the uploader to save the file.

Everything works as planned as long as the button is initially enabled. However, if the button starts out disabled then the cross page postback doesn't occur.

This is hard for me to explain clearly so I'm including some code I was testing with. There are two buttons on this page. The only difference between the buttons, besides their ID, is that one button is initially disabled and the other one is enabled. The file is uploaded when either button is clicked. But only the button which is initally enabled sends a response to the second page.

I did notice there was a query in the URL after testing with the disabled button: test.aspx?RadUrid=4ec5a3c0-0503-422b-83d0-743982ca7ffa

I also tried, without luck, the suggestion in this post ASyncUpload Issue? forum post since it was possible the problem was caused by the same factors.

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="test.aspx.vb" Inherits="test" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

<head runat="server">

<title></title>

</head>

<body>

<form id="form1" runat="server">

<telerik:RadScriptManager ID="RadScriptManager1" runat="server">

</telerik:RadScriptManager>

<telerik:RadCodeBlock ID="RadCodeBlock1" runat="server">

<script type="text/javascript">

//<![CDATA[

function fileUploaded(sender, eventArgs) {

var btn = $get("<%= Me.BTN_loadfile.ClientID%>");

if (typeof (btn) != "defined") {

btn.disabled = false;

}

//]]>

</script>

</telerik:RadCodeBlock>

<telerik:RadProgressManager ID="RPM_importAdmin" runat="server" />

<br />

File to load administrators from (.CSV,.XLS, or .XLSX):

<br />

<telerik:RadAsyncUpload ID="RAU_uploadFile" MaxFileInputsCount="1" MaxFileSize="10485760" InputSize="60" AllowedFileExtensions="csv,xls,xlsx" runat="server" OverwriteExistingFiles="true" OnClientFileUploaded="fileUploaded" >

<Localization Select="Browse" />

</telerik:RadAsyncUpload>

<br />

<telerik:RadProgressArea ID="RPA_uploadFile" DisplayCancelButton="true" runat="server">

</telerik:RadProgressArea>

<asp:Button ID="BTN_loadfile" runat="server" Text="Should Go" Enabled="false" CausesValidation="false" PostBackUrl="~/test2.aspx"></asp:Button>

<asp:Button ID="Button1" runat="server" Text="Goes" CausesValidation="false" PostBackUrl="~/test2.aspx"></asp:Button>

<br />

</form>

</body>

</html

The code-behind for the SECOND page is the following. The code-behind for the first page just sets values for the TemporaryFolder and TargetFolder properties.

Imports System.IO

Imports Telerik.Web.UI

Partial Class test2

Inherits System.Web.UI.Page

Protected fileUploader As RadAsyncUpload = Nothing

Protected Sub Page_PreInit(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreInit

If PreviousPage Is Nothing Then

If Not IsPostBack Then

Me.Label1.Text = "no previous page"

End If

Else

Me.fileUploader = CType(PreviousPage.Form.FindControl("RAU_uploadFile"), RadAsyncUpload)

If Me.fileUploader IsNot Nothing AndAlso Me.fileUploader.UploadedFiles.Count > 0 Then

Me.Label1.Text = "File: " & Path.Combine(Me.fileUploader.TargetFolder, Me.fileUploader.UploadedFiles(0).FileName)

End If

End Sub

End Class

The version of the Telerik .dll is: 2010.3.1215.35

Any help or ideas would be greatly appreciated.

Thanks,

3 Answers, 1 is accepted

answered on 07 Jan 2011, 01:32 PM

Hello K,

This is not a problem with RadAsyncUpload but with the way ASP.NET handles disabled buttons. In order to workaround the issue removed the Enabled="false" declaration from the button and, instead, disable it on the client using the following script:

Sys.Application.add_load(function() {

$get("BTN_loadfile").disabled = "disabled";

});

Best wishes,
Genady Sergeev
the Telerik team

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