Showing Image Loader while performing Paging in GridView

Ascx

<%@ Assembly Name="$SharePoint.Project.AssemblyFullName$" %> <%@ Assembly Name="Microsoft.Web.CommandUI, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %> <%@ Register Tagprefix="SharePoint" Namespace="Microsoft.SharePoint.WebControls" Assembly="Microsoft.SharePoint, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %> <%@ Register Tagprefix="Utilities" Namespace="Microsoft.SharePoint.Utilities" Assembly="Microsoft.SharePoint, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %> <%@ Register Tagprefix="asp" Namespace="System.Web.UI" Assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" %> <%@ Import Namespace="Microsoft.SharePoint" %> <%@ Register Tagprefix="WebPartPages" Namespace="Microsoft.SharePoint.WebPartPages" Assembly="Microsoft.SharePoint, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %> <%@ Control Language="C#" AutoEventWireup="true" CodeBehind="ImageLoadingGridViewUserControl.ascx.cs" Inherits="ImageLoadingGridView.ImageLoadingGridView.ImageLoadingGridViewUserControl" %> <%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="cc1" %> <asp:Label ID="lblMessage" runat="server"></asp:Label> <asp:UpdatePanel ID="UpdatePanel1" runat="server"> <ContentTemplate> <asp:UpdateProgress ID="UpdateProgress1" runat="server" AssociatedUpdatePanelID="UpdatePanel1"> <ProgressTemplate> <img alt="progress" src="/UserPages/Loading_Images/loading_1.gif" />          </ProgressTemplate> </asp:UpdateProgress> <asp:GridView ID="dgvMovingImage" runat="server" AutoGenerateColumns="False"         Width="100%" AllowPaging="True" CellPadding="4" EnableModelValidation="True"         ForeColor="#333333"         onpageindexchanging="dgvMobingImage_PageIndexChanging" PageSize="20">     <AlternatingRowStyle BackColor="White" /> <Columns> <asp:BoundField HeaderText="ItemID" DataField="ID" /> <asp:BoundField HeaderText="Title" DataField="Title" /> </Columns>     <EditRowStyle BackColor="#2461BF" />     <FooterStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />     <HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />     <PagerSettings Mode="NextPrevious" NextPageText="Next"         PreviousPageText="Previous" />     <PagerStyle BackColor="#2461BF" ForeColor="White" HorizontalAlign="Center" />     <RowStyle BackColor="#EFF3FB" />     <SelectedRowStyle BackColor="#D1DDF1" Font-Bold="True" ForeColor="#333333" /> </asp:GridView> </ContentTemplate> </asp:UpdatePanel>

Ascx.Cs

using System; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using Microsoft.SharePoint; using System.Security; namespace ImageLoadingGridView.ImageLoadingGridView {     public partial class ImageLoadingGridViewUserControl : UserControl     {         protected void Page_Load(object sender, EventArgs e)         {             if (!IsPostBack)             {                 getData();             }         }         protected void dgvMobingImage_PageIndexChanging(object sender, GridViewPageEventArgs e)         {             try             {                 System.Threading.Thread.Sleep(3000);                 dgvMovingImage.PageIndex = e.NewPageIndex;                 getData();             }             catch (Exception Ex)             {                 lblMessage.Text = Ex.ToString();             }         }         public void getData()         {             try             {                 SPSecurity.RunWithElevatedPrivileges(delegate()                 {                     SPQuery strQuery = new SPQuery();                     strQuery.Query = "";                     SPListItemCollection myColl = SPContext.Current.Web.Lists["Moving Image Test"].GetItems(strQuery);                     if (myColl.Count > 0)                     {                         dgvMovingImage.DataSource = myColl.GetDataTable();                         dgvMovingImage.DataBind();                     }                 });             }             catch (Exception Ex)             {                 lblMessage.Text = Ex.ToString();             }         }     } }