Random issue: AJAX post back not sending asp:DropDown selected value back to server

2 posts, 0 answers
  1. gg
    gg avatar
    1 posts
    Member since:
    Mar 2012

    Posted 26 Mar 2012 Link to this post

    I have a very simple Telerik AJAX setup in one page, and it works well most of the time, but it sometimes enters into a state where dropdowns won't send their selected values back to the server in AJAX posts anymore.

    This is basically what I have (simplified for the purpose of posting it here, the actual page is much much bigger):

    <%@ Page Language="VB" MasterPageFile="~/Admin/_MasterPages/Default.master" AutoEventWireup="false"<br>    ValidateRequest="false" MaintainScrollPositionOnPostback="true" CodeFile="Edit.aspx.vb"<br>    Inherits="Admin_Setup_Edit" %><br><br><asp:Content ID="Content1" ContentPlaceHolderID="SubNavigationContentPlaceHolder"<br>    runat="Server"><br></asp:Content><br><asp:Content ID="Content2" ContentPlaceHolderID="MainContentPlaceHolder" runat="Server"><br>    <telerik:RadAjaxManager ID="RadAjaxManager" runat="server">        <br>    </telerik:RadAjaxManager><br>    <telerik:RadCodeBlock ID="CodeBlock1" runat="server">    <br>        <script type="text/javascript"><br><br>            var AddEvent_ShowLoader = function () {<br>                JS.showLoader();<br>            }<br><br>            var AddEvent_HideLoader = function () {<br>                JS.hideLoader();<br>            }<br><br>        </script><br>    </telerik:RadCodeBlock><br>    <telerik:RadAjaxPanel ID="mainAjaxPanel" runat="server" ClientEvents-OnRequestStart="AddEvent_ShowLoader"<br>        ClientEvents-OnResponseEnd="AddEvent_HideLoader" LoadingPanelID="MasterRadAjaxLoadingPanel"><br>        <table cellpadding="0" cellspacing="0" width="100%"><br>            <tr><br>                [[... a lot of other rows here... ]]<br>            </tr>            <br>            <tr><br>                <td class="BorderRight"><br>                    <asp:DropDownList ID="ddlStatus" runat="server"><br>                    </asp:DropDownList><br>                </td>                <br>                <td><br>                    <asp:DropDownList ID="ddlType" runat="server"><br>                    </asp:DropDownList><br>                </td><br>            </tr><br>            <tr><br>                [[... a lot of other rows here... ]]<br>            </tr>            <br>        </table><br>    </telerik:RadAjaxPanel><br></asp:Content>

    Values from dropdowns will come as empty strings, which is incorrect.
    Please note that this is a random issue, so there must be something that's getting corrupted somehow and I need to know why.

    Have someone experienced this before? Any pointers on what the problem could be?

  2. Andrey
    Andrey avatar
    836 posts

    Posted 29 Mar 2012 Link to this post


    Based on your code I see you are using both the RadAjaxManager and RadAjaxPanel. Is there any particular reason for doing this? As this help topic says you could use RadAjaxManager in any scenario.

    Additionally, what the JS.showLoader() and JS.hideLoader() function are doing? If you are using RadAjaxLoadingPanel you do not need to show the loading panel explicitly.

    If the aforementioned functions are used to show/hide explicitly the loading panel, try to remove them and check whether the issue is resolved.

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