asp.net gridview实现正在加载效果方案一AJAX(转)

前台代码：

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!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>
  
</head>
<body>
     <form id="form1" runat="server">
    <div>

        <asp:ScriptManager ID="ScriptManager1" runat="server">
        </asp:ScriptManager>
        <asp:UpdatePanel ID="UpdatePanel1" runat="server">
            <ContentTemplate>
                <fieldset>
                <legend>UpdatePanel</legend>
                <asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" />
                <asp:UpdateProgress ID="UpdateProgress1" runat="server">
        <ProgressTemplate>
        正在加载数据.............
        </ProgressTemplate>
        </asp:UpdateProgress>
                <asp:GridView ID="GridView1" runat="server"
            onrowcreated="GridView1_RowCreated"
            onpageindexchanging="GridView1_PageIndexChanging" Width="1000px"
         onrowdatabound="GridView1_RowDataBound"
             EmptyDataText="没有查询到您所需要的数据" PageSize="15" AllowPaging="True" >
                <FooterStyle CssClass="GridViewFooterStyle" />
                <RowStyle CssClass="GridViewRowStyle" />
                <SelectedRowStyle CssClass="GridViewSelectedRowStyle" />
               <PagerStyle CssClass="GridViewPagerStyle" />
    <AlternatingRowStyle CssClass="GridViewAlternatingRowStyle" />
    <HeaderStyle CssClass="GridViewHeaderStyle" />

        </asp:GridView>
                </fieldset>
            </ContentTemplate>
        </asp:UpdatePanel>

    </div>
    </form>
</body>
</html>

后台cs代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.SqlClient;
using System.Data;

public partial class _Default : System.Web.UI.Page
{
   
    

    protected void Page_Load(object sender, EventArgs e)
    {
        
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        System.Threading.Thread.Sleep(3000);
        databind();
    }
    public void databind()
    {
        string sql = "SELECT [orderid], [customerid], [shipvia], [shipname] FROM [orders]";
        string con = "Data Source=.;Initial Catalog=northwind;User ID=sa;Password=19790601";
        SqlConnection mycon = new SqlConnection(con);
        mycon.Open();
        SqlDataAdapter mydt = new SqlDataAdapter(sql, mycon);
        DataSet ds = new DataSet();
        mydt.Fill(ds);
        GridView1.DataSource = ds;
        GridView1.DataBind();
        mycon.Close();
    }
    protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
    {
        GridView1.PageIndex = e.NewPageIndex;
        databind();
    }
}