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Using RadXmlHttpPanel with RadAjaxPanel

Customers by Countries
Order IDOrder DateShip NameShip CityShip Country
 Page 1 of 83, items 1 to 10 of 821.
102507/8/1996 12:00:00 AMHanari Carnes Brazil
102527/9/1996 12:00:00 AMSuprêmes délicesCharleroiBelgium
102567/15/1996 12:00:00 AMWellington ImportadoraResendeBrazil
102587/17/1996 12:00:00 AMErnst HandelGrazAustria
102617/19/1996 12:00:00 AMQue DelíciaRio de JaneiroBrazil
102637/23/1996 12:00:00 AMErnst Handel Austria
102657/25/1996 12:00:00 AMBlondel père et filsStrasbourgFrance
102667/26/1996 12:00:00 AMWartian HerkkuOuluFinland
102677/29/1996 12:00:00 AMFrankenversandMünchenGermany
102697/31/1996 12:00:00 AMWhite Clover MarketsSeattleUSA

The following example demonstrates how to benefit by using the RadAjaxPanel combined with the RadXmlHttpPanel.

A RadGrid is hosted in a RadXmlHttpPanel, and the RadXmlHttpPanel itself is wrapped by a RadAjaxPanel. The RadXmlHttpPanel populates the RadGrid by loading on-demand content, while the RadAjaxPanel ensures that all of the (RadGrid's) events are fired correctly and trigger Ajax partial updates. This way we have optimum performance and take full advantage of what each panel does best.

Note: RadGrid's Insert/Update/Delete operations are not supported in this scenario (RadXmlHttpPanel in RadAjaxPanel), because they rely heavily on the ViewState. Since the ViewState is not updated on ASP.NET client callbacks, on the next row Insert/Update/Delete the incorrect row will be affected, and this will cause data inconsistency. That's why this setup should be used in simpler scenarios, where the ViewState is not that important.

  • DefaultVB.aspx
  • DefaultVB.aspx.vb
  • scripts.js
<%@ Page Language="vb" AutoEventWireup="true" Inherits="Telerik.Web.Examples.XmlHttpPanel.GridInXmlHttpPanel.DefaultVB"CodeFile="DefaultVB.aspx.vb"  %>

<!DOCTYPE html>
<html xmlns=''>
<head runat="server">
    <title>Telerik ASP.NET Example</title>
    <form id="form1" runat="server">
    <telerik:RadScriptManager runat="server" ID="RadScriptManager1" />
    <telerik:RadSkinManager ID="RadSkinManager1" runat="server" ShowChooser="true" />
    <div class="demo-container">
        <div style="margin-bottom: 10px;">
            <span style="margin-right: 15px;">Customers by Countries</span>
            <telerik:RadComboBox RenderMode="Lightweight" ID="RadComboBox1" runat="server" OnClientSelectedIndexChanged="telerikDemo.setValue"
                AllowCustomText="true" Filter="Contains" DataSourceID="SqlDataSource1" DataTextField="Country" EmptyMessage="Choose a country..."
        <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>"
            SelectCommand="SELECT DISTINCT [Country] FROM [Customers] Order By [Country]"></asp:SqlDataSource>
        <telerik:RadAjaxPanel ID="RadAjaxPanel1" runat="server">
            <telerik:RadXmlHttpPanel ID="RadXmlHttpPanel1" runat="server" EnableClientScriptEvaluation="true"
                OnServiceRequest="XmlHttpPanel1_ServiceRequest" RenderMode="Block">
                <telerik:RadGrid RenderMode="Lightweight" ID="RadGrid1" runat="server" OnNeedDataSource="RadGrid1_NeedDataSource"
                    Width="100%" AllowSorting="True" PageSize="10" AllowPaging="True" AllowMultiRowSelection="True"
                    <PagerStyle Mode="NumericPages"></PagerStyle>
    <script src="scripts.js" type="text/javascript"></script>
    <telerik:RadScriptBlock ID="RadScriptBlock1" runat="server">
        <script type="text/javascript">
            Sys.Application.add_load(function() {
                telerikDemo.radXmlHttpPanel = $find("<%=RadXmlHttpPanel1.ClientID %>");

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