System.Web.HttpException: Server cannot append header after HTTP headers have been sent.

Generated: Mon, 01 Jun 2009 18:55:13 GMT

System.Web.HttpException: Server cannot append header after HTTP headers have been sent.

   at System.Web.HttpResponse.AppendHeader(String name, String value)

   at Telerik.Web.UI.RadCompression.application_EndRequest(Object sender, EventArgs e)

   at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()

   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

I have a basic setup like below for a grid. I just want to have the gradient padded background on the details table that  a lot of the samples have in order to improve how the data appears. I believe it has something to do with the nestedview settings, but I'm not sure how to use it with the detailtables view. For instance, it looks like the samples apply a viewwrap css class to the details, but they all use outputted html, while i'm using a gridtableview. I'm not sure how to apply it in my situation.

<telerik:RadGrid ID="DevelopmentGoalGrid" runat="server" ..>

<MasterTableView DataKeyNames="GoalId" DataSourceID="GoalsData" HierarchyDefaultExpanded="true"

TableLayout="Auto" AllowPaging="false">

<DetailTables>

<telerik:GridTableView Name="ActivityDetails" DataKeyNames="ActivityId" Width="100%"

runat="server" AutoGenerateColumns="false" AllowPaging="false" CssClass="viewWrap" nes >

<ParentTableRelation>

<telerik:GridRelationFields DetailKeyField="GoalId" MasterKeyField="GoalId" />

</ParentTableRelation>

<RowIndicatorColumn>

<HeaderStyle Width="20px" />

</RowIndicatorColumn>

<ExpandCollapseColumn>

<HeaderStyle Width="20px" />

</ExpandCollapseColumn>

<Columns>

<telerik:GridButtonColumn Text="Select" ButtonType="LinkButton" CommandName="SelectActivity" />

<telerik:GridBoundColumn HeaderText="Activity" UniqueName="ActivityName" DataField="Name"

SortExpression="Name">

</telerik:GridBoundColumn></Columns>

</telerik:GridTableView>

</DetailTables>

<RowIndicatorColumn>

<HeaderStyle Width="20px"></HeaderStyle>

</RowIndicatorColumn>

<ExpandCollapseColumn Visible="True">

<HeaderStyle Width="20px"></HeaderStyle>

</ExpandCollapseColumn>

<Columns>

</Columns>

</MasterTableView>

<ClientSettings>

<Selecting AllowRowSelect="True" />

</ClientSettings>

</telerik:RadGrid>

@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="_Default" %>

<%

@ Register TagPrefix="telerik" Namespace="Telerik.Web.UI" Assembly="Telerik.Web.UI" %>

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>

<script language="javascript" type="text/javascript">

function populateContextMenu()

{

var ctxMenu = Sys.Application.findComponent('ctx');

ctxMenu.get_items().clear();

for (var i = 0; i < 10; i++)

{

var menuItem = new Telerik.Web.UI.RadMenuItem();

ctxMenu.get_items().add(menuItem);

menuItem.set_value(i.toString());

menuItem.set_text(i.toString());

if (i == 2)

{

menuItem.set_selected(

true);

}

': ' + menuItem.get_selected());

}

return false;

}

</script>

</

head>

<

body>

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

<asp:ScriptManager ID="ScriptManager1" runat="server" />

<div>

<telerik:radcontextmenu id="ctx" runat="server" skin="Black" >

</telerik:radcontextmenu>

<asp:Button ID="btn" Text="Populate" runat="server" OnClientClick="populateContextMenu(); return false;" />

</div>

</form>

</

body>

</

html>