Rating控件提供一个具有特殊效果的等级，而且以图片的样式展现的。
属性列表：
MaxRating ：最高可以给予的等级高低
CurrentRating ：当前等级
CssClass : 指定评级控件所套用的样式表。
StarCssClass ：星的样式
WaitingStarCssClass :更改等级时星的显示样式
FilledStarCssClass :设置等级后星的显示样式
EmptyStarCssClass ：没有选中时等级的显示样式
AutoPostBack ：是否支持页面回发
OnChanged ：等级变化时触发的事件
Tag:为事件传递的参数
常见问题和使用技巧：
常见问题：可不可以不使用Rating控件的自动异步回调功能，而是随着表单一起传回服务器？
使用技巧：int rating=myRatingID.CurrentRating;可以获得当前评级。
实例解析一、简单使用实例（必须为此控件添加样式和图片不然运行错误）
1.UI界面
<head runat="server">
<title>无标题页</title>
<style>
.ratingstar{
font-size:0pt;
15px;
height:12px;
margin:1px;
padding:1px;
currsor:pointer;
display:block;
background-repeat:no-repeat;
}
.filledratingstar{
background-image:url(1.gif);
}
.emptyratingstar{
background-image:url(2.gif);
}
.savedratingstar{
background-image:url(3.gif);
}
</style>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:ScriptManager ID="ScriptManager1" runat="server"></asp:ScriptManager>
</div>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<table style=" 361px; height: 81px">
<tr>
<td style=" 56px">姓名：</td>
<td style=" 100px"><asp:TextBox ID="TextBox1" runat="server"></asp:TextBox></td>
</tr>
<tr>
<td style=" 56px; height: 20px"> 等级：</td>
<td >
<cc1:rating id="Rating1" runat="server" currentrating="2" height="13px" maxrating="8" AutoPostBack="true" OnChanged="Rating1_Changed"
StarCssClass="ratingstar" EmptyStarCssClass="emptyratingstar" FilledStarCssClass="filledratingstar" WaitingStarCssClass="savedratingstar"></cc1:rating>
</td>
</tr>
<tr>
<td style=" 56px"></td>
<td style=" 100px"><asp:Label ID="Label1" runat="server" Text="Label"></asp:Label></td>
</tr>
</table>
</ContentTemplate>
</asp:UpdatePanel>
</form>
</body>
2.后台
protected void Rating1_Changed(object sender, AjaxControlToolkit.RatingEventArgs e)
{
if (int.Parse(e.Value) < 4)
{
Label1.Text = "对不起，最低为4级！";
}
int temp;
Math.DivRem(int.Parse(e.Value),2,out temp);
if (temp != 0)
{
Label1.Text = "对不起，等级必须是468！";
}
}
实例解析二、和数据库相关联的实例（两张图片见附件）
<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
protected void rating_Changed(object sender, RatingEventArgs e)
{
MusicData.UpdateMusicRate(int.Parse(e.Tag), int.Parse(e.Value));
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title>Rating Demo</title>
<link href="StyleSheet.css" rel="stylesheet" type="text/css" />
</head>
<body>
<form id="form1" runat="server">
<asp:ScriptManager ID="sm" runat="server" />
<asp:GridView ID="musicGrid" runat="server" AutoGenerateColumns="False" DataSourceID="musicDataSource"
Width="400px">
<Columns>
<asp:BoundField DataField="Name" HeaderText="Name" SortExpression="Name" />
<asp:TemplateField HeaderText="Rating" SortExpression="Rating">
<ItemTemplate>
<ajaxToolkit:Rating ID="rating" runat="server" StarCssClass="ratingStar" FilledStarCssClass="filledRatingStar"
EmptyStarCssClass="emptyRatingStar" WaitingStarCssClass="filledRatingStar" CurrentRating='<%# Bind("Rating") %>'
MaxRating="5" Tag='<%# Bind("Id") %>' OnChanged="rating_Changed">
</ajaxToolkit:Rating>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
<asp:ObjectDataSource ID="musicDataSource" runat="server" DataObjectTypeName="MusicEntry"
SelectMethod="GetMusicList" TypeName="MusicData"></asp:ObjectDataSource>
</form>
</body>
2.类文件
using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.ComponentModel;
using System.Collections.Generic;
/// <summary>
/// Summary description for MusicData
/// </summary>
[DataObject(true)]
public class MusicData
{
private static List<MusicEntry> m_data;
private static List<MusicEntry> data
{
get
{
if (m_data == null)
{
m_data = new List<MusicEntry>();
Random rand = new Random();
m_data.Add(new MusicEntry(0, "Polonaise in A. Op 40, No. 1 (\"Military\")", rand.Next(6), 0));
m_data.Add(new MusicEntry(1, "Nocturne in E-Flat, Op. 9, No. 2", rand.Next(6), 1));
m_data.Add(new MusicEntry(2, "Waltz in A-Flat, Op. 34, No. 1 (\"Valse brillante\")", rand.Next(6), 2));
m_data.Add(new MusicEntry(3, "Waltz in C-sharp Minor, Op. 64, No. 2", rand.Next(6), 3));
m_data.Add(new MusicEntry(4, "Waltz in D-Flat, Op. 64, No. 1 (\"Minute\" Waltz)", rand.Next(6), 4));
m_data.Add(new MusicEntry(5, "Polonaise in A-Flat, Op. 53 (\"Heroic\")", rand.Next(6), 5));
m_data.Add(new MusicEntry(6, "Mazurka in D, Op. 33, No. 2", rand.Next(6), 6));
m_data.Add(new MusicEntry(7, "Fantaisie-Impromptu in C-Sharp Minor, Op. 66", rand.Next(6), 7));
m_data.Add(new MusicEntry(8, "Mazurka in B-Flat, Op. 7, No. 1", rand.Next(6), 8));
m_data.Add(new MusicEntry(9, "Nocturne in G Minor, Op. 37, No. 1", rand.Next(6), 9));
}
return m_data;
}
}
[DataObjectMethod(DataObjectMethodType.Select)]
public static List<MusicEntry> GetMusicList()
{
data.Sort(CompareMusicEntry);
return data;
}
private static int CompareMusicEntry(MusicEntry x, MusicEntry y)
{
return x.Order.CompareTo(y.Order);
}
[DataObjectMethod(DataObjectMethodType.Update)]
public static void UpdateMusic(MusicEntry music)
{
for (int i = 0; i < data.Count; ++i)
{
if (data[i].Id == music.Id)
{
m_data[i] = music;
break;
}
}
}
public static void UpdateMusicRate(int id, int rating)
{
for (int i = 0; i < data.Count; ++i)
{
if (data[i].Id == id)
{
m_data[i].Rating = rating;
break;
}
}
}
}