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Using RadXmlHttpPanel with RadAjaxPanel

Customers by Countries
Order IDOrder DateShip NameShip CityShip Country
12345678910...
 Page 1 of 83, items 1 to 10 of 830.
102487/4/1996 12:00:00 AMVins et alcools ChevalierReimsFrance
102497/5/1996 12:00:00 AMToms SpezialitätenMünsterGermany
102507/8/1996 12:00:00 AMHanari CarnesRio de JaneiroBrazil
102517/8/1996 12:00:00 AMVictuailles en stockLyonFrance
102527/9/1996 12:00:00 AMSuprêmes délicesCharleroiBelgium
102537/10/1996 12:00:00 AMHanari CarnesRio de JaneiroBrazil
102547/11/1996 12:00:00 AMChop-suey ChineseBernSwitzerland
102557/12/1996 12:00:00 AMRichter SupermarktGenèveSwitzerland
102567/15/1996 12:00:00 AMWellington ImportadoraResendeBrazil
102577/16/1996 12:00:00 AMHILARION-AbastosSan CristóbalVenezuela

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='http://www.w3.org/1999/xhtml'>
<head runat="server">
    <title>Telerik ASP.NET Example</title>
</head>
<body>
    <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..."
                Style="">
            </telerik:RadComboBox>
        </div>
        <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"
                    GridLines="None">
                    <PagerStyle Mode="NumericPages"></PagerStyle>
                </telerik:RadGrid>
            </telerik:RadXmlHttpPanel>
        </telerik:RadAjaxPanel>
    </div>
    <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 %>");
            });
        </script>
    </telerik:RadScriptBlock>
    </form>
</body>
</html>

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