Repeater+AspNetPager+Ajax留言板
主要结构：
1.前期准备
2.Repeater+AspNetPager分页效果
3.Ajax无刷新留言板，插入和删除留言
4.自定义编号
5.总结
先上效果图：（PS：美工很一般）
1.前期准备：
1.数据库：自增ID，用户名，留言内容，用户头像，留言时间。
2.实体类：对应数据库的字段
View Code
1 public class MessageClass
2 {
3 private int id;
4 public int ID //自增ID
5 {
6 get { return id; }
7 set { id = value; }
8 }
9
10 private string username;
11 public string UserName //用户名
12 {
13 get { return username; }
14 set { username = value; }
15 }
16
17 private string usermessage;
18 public string UserMessage //留言内容
19 {
20 get { return usermessage; }
21 set { usermessage = value; }
22 }
23
24 private string userimage;
25 public string UserImage //用户头像
26 {
27 get { return userimage; }
28 set { userimage = value; }
29 }
30
31 private DateTime usertime;
32 public DateTime UserTime //留言时间
33 {
34 get { return usertime; }
35 set { usertime = value; }
36 }
37 }
3.数据访问层：
View Code
1 public class SqlHelper
2 {
3 public readonly static string connectionString = ConfigurationManager.ConnectionStrings["connstring"].ToString();
4
5 public static SqlConnection conn = new SqlConnection(connectionString);
6
7 public static void OpenConnection()
8 {
9
10 if (conn.State != ConnectionState.Open)
11 {
12 try
13 {
14 conn.Open();
15 }
16 catch (Exception ex)
17 {
18 conn.Dispose();
19 throw new Exception("Connect Database error!" + ex.Message);
20 }
21 }
22 }
23
24 public static void CloseConnection()
25 {
26 if (conn.State==ConnectionState.Open)
27 {
28 try
29 {
30 conn.Close();
31 }
32 catch (Exception ex)
33 {
34 conn.Dispose();
35 throw new Exception("Close Database error!" + ex.Message);
36 }
37 }
38 }
39
40 /// <summary>
41 /// 执行带参数的SQL语句
42 /// </summary>
43 /// <param name="sql"></param>
44 /// <returns></returns>
45 public static bool ExecuteNoReturn(string sql)
46 {
47 try
48 {
49 SqlCommand comm = new SqlCommand(sql, conn);
50 OpenConnection();
51 comm.ExecuteNonQuery();
52 CloseConnection();
53 return true;
54 }
55 catch (Exception ex)
56 {
57 return false;
58 throw new Exception("Error:" + ex);
59 }
60 }
61
62 /// <summary>
63 /// 执行带参数的SQL语句,返回个数
64 /// </summary>
65 /// <param name="sql"></param>
66 /// <returns></returns>
67 public static int ExecuteReturnCount(string sql)
68 {
69 try
70 {
71 SqlCommand comm = new SqlCommand(sql, conn);
72 OpenConnection();
73 int count =(int) comm.ExecuteScalar();
74 CloseConnection();
75 return count;
76 }
77 catch (Exception ex)
78 {
79 return 0;
80 throw new Exception("Error:" + ex);
81 }
82 }
83
84 /// <summary>
85 /// 执行SQL命令,将数据赋给数据集
86 /// </summary>
87 /// <param name="sql"></param>
88 /// <returns></returns>
89 public static DataTable ExcuteSqlReturnTable(string sql)
90 {
91 try
92 {
93 OpenConnection();
94 SqlCommand comm = new SqlCommand(sql, conn);
95 SqlDataAdapter adpater = new SqlDataAdapter(comm);
96 DataTable dt = new DataTable();
97 adpater.Fill(dt);
98 CloseConnection();
99 return dt;
100 }
101 catch (Exception ex)
102 {
103 return null;
104 throw new Exception("Error:" + ex);
105 }
106
107 }
108 }
2.Repeater+AspNetPager分页效果
一直都用Repeater控件，灵活性高，但是之前的分页都是自己手写的，感觉比较繁琐。于是就尝试用了AspNetPager分页控件，效果还是挺不错的。
我将总记录数，每页显示的项数，当前页索引声明为public，是为了插入数据时，js引用，从而实现自动倒序排列的功能。
前台代码：
View Code
1 <div id="msglist">
2 <asp:Repeater ID="Rep" runat="server">
3 <ItemTemplate>
4 <table class="tablestyle">
5 <tr>
6 <td class="lf">
7 <ul>
8 <li><a href="#"><img src='<%#Eval("UserImage") %>' alt="0"/></a></li>
9 <li><em><%#Eval("UserName") %></em></li>
10 <li>(<%#Eval("UserName") %>)</li>
11 <li>等级：★★★★★</li>
12 <li>结贴率：100%</li>
13 </ul>
14 </td>
15 <td class="rw">
16 <div class="fbart">发表于：<%#Eval("UserTime", "{0:yyyy-M-dd HH:mm:ss}")%><em><%#RowsCount - (PageNum-1) *PageSize- Container.ItemIndex%></em></div>
17 <div class="msgfont"><%#Eval("UserMessage") %></div>
18 <div class="fdart"><span class='<%#Eval("ID") %>'><a href="" class="btndelete" onclick="return false">删除</a></span></div>
19 </td>
20 </tr>
21 </table>
22 </ItemTemplate>
23 </asp:Repeater>
24 </div>
25 <div id="page">
26 <webdiyer:AspNetPager ID="AspNetPager1" OnPageChanged="AspNetPager1_PageChanged" CssClass="paginator" CurrentPageButtonPosition="Center" PageIndexBoxType="DropDownList" ShowPageIndexBox="Always" SubmitButtonText="Go" TextAfterPageIndexBox="页" TextBeforePageIndexBox="转到" runat="server" >
27 </webdiyer:AspNetPager>
28 </div>
后台代码：
View Code
1 protected void Page_Load(object sender, EventArgs e)
2 {
3 if (!IsPostBack)
4 {
5 AspNetPagerConfig();
6 MessageList();
7 }
8 }
9 //总记录数
10 private int rowscount= 0;
11 protected int RowsCount
12 {
13 get{ return rowscount;}
14 set{this.rowscount = value;}
15 }
16 //每页显示的项数
17 private int pagesize = 0;
18 protected int PageSize
19 {
20 get { return pagesize; }
21 set {this.pagesize=value; }
22 }
23 //当前索引
24 private int pagenum = 0;
25 protected int PageNum
26 {
27 get { return pagenum; }
28 set { this.pagenum = value; }
29 }
30 //AspNetPager配置
31 protected void AspNetPagerConfig()
32 {
33 string sql = "select count(*) from T_BBS";
34 int count = SqlHelper.ExecuteReturnCount(sql);
35 AspNetPager1.RecordCount = count;//设置总页数
36 RowsCount = count;
37 AspNetPager1.PageSize = 2;
38 AspNetPager1.PrevPageText = "上一页";
39 AspNetPager1.NextPageText = "下一页";
40 AspNetPager1.FirstPageText = "首页";
41 AspNetPager1.LastPageText = "尾页";
42 AspNetPager1.ShowFirstLast = false;
43 AspNetPager1.ShowMoreButtons = false;
44 }
45
46 //绑定Repeater数据源
47 protected void MessageList()
48 {
49 pagesize = AspNetPager1.PageSize;//得到每页显示的项数
50 pagenum = AspNetPager1.CurrentPageIndex;//得到当前页索引
51 int count2 = (pagenum - 1) * pagesize;
52 string sql = "select top " + pagesize + " * from T_BBS where id not in(select top " + count2 + " id from T_BBS order by usertime desc) order by usertime desc ";
53 DataTable dt = SqlHelper.ExcuteSqlReturnTable(sql);
54 Rep.DataSource = dt;
55 Rep.DataBind();
56 }
57
58 // AspNetPager控件改变页事件
59 protected void AspNetPager1_PageChanged(object src, EventArgs e)
60 {
61 AspNetPagerConfig();
62 MessageList();
63 }
3.Ajax无刷新留言板，增加删除留言
主要通过一般处理程序ashx处理提交的数据，再根据自己的需求返回数据
删除留言可以有两个方法：1.根据查找返回的id，这个正是本文所提到的。 2.根据查找用户留言的时间，之后完善会做到这个方面。
js代码：
View Code
1 //插入留言
2 $("#btnInsert").click(function () {
3 if ($("#txtname").val() == "若不填则为匿名") {
4 var username = "匿名";
5 }
6 else {
7 var username = $("#txtname").val(); //用户名
8 }
9 var usermessage = $("#txtmessage").val(); //留言内容
10 var Time = new Date();
11 var usertime = Time.getFullYear() + "-" + (Time.getMonth() + 1) + "-" + Time.getDate() + " " + Time.getHours() + ":" + Time.getMinutes() + ":" + Time.getSeconds(); //获取留言的时间
12 var RowsCount = "<%=RowsCount %>";
13 var PageSize = "<%=PageSize %>";
14 var PageNum = "<%=PageNum %>";
15 $.ajax({
16 type: "POST",
17 url: "Handler/Message.ashx?method=add",
18 data: "username=" + username + "&usermessage=" + usermessage + "&userimage=" + userimage + "&usertime=" + usertime + "",
19 success: function (data) {
20 if (data != "-1") {
21 num++;
22 $("#msglist").prepend("<table class='tablestyle'><tr><td class='lf'><ul><li><a href='#'><img src='" + userimage + "'alt='0'/></a></li><li><em>" + username + "</em></li><li>(" + username + ")</li><li>等级：★★★★★</li><li>结贴率：100%</li></ul></td><td class='rw'><div class='fbart'>发表于：" + usertime + "<em>" + (RowsCount - (PageNum - 1) * PageSize + num) + "</em></div><div class='msgfont'>" + usermessage + "</div><div class='fdart'><span class=" + data + "><a href='' class='btndelete' onclick='return false'>删除</a></span></div></td></tr></table>");
23 $(".btndelete").bind("click", deleteEvent); //重新绑定删除按钮事件
24 }
25 }
26 });
27 });
28 //删除留言
29 $(".btndelete").click("click", deleteEvent);
30 var deleteEvent = function () {
31 if (!confirm("是否确定要删除这条留言"))
32 return false;
33 var deletelist = $(this).parent(); //获取父标签
34 var deletepar = $(this).parents(".tablestyle"); //获取当前tablestyle
35 var id = deletelist.attr("class"); //获取要删除行的id值
36 $.ajax({
37 type: "POST",
38 url: "Handler/Message.ashx?method=delete",
39 data: "id=" + id + "",
40 success: function (data) {
41 if (data == "success") {
42 deletepar.animate({ opacity: 'hide' }, "slow", function () { deletepar.remove(); });
43 }
44 }
45 });
46 }
一般处理程序代码：
View Code
1 public void ProcessRequest (HttpContext context) {
2 context.Response.ContentType = "text/plain";
3 string method = context.Request.Params["method"].ToString();//获取想要做的操作
4 if (method == "add")
5 {
6 MessageClass message = new MessageClass();//创建新的留言对象
7 message.UserName = context.Request.Params["username"].ToString();
8 message.UserMessage = context.Request.Params["usermessage"].ToString();
9 message.UserImage = context.Request.Params["userimage"].ToString();
10 message.UserTime = Convert.ToDateTime(context.Request.Params["usertime"].ToString());
11 InsertMessage(message, context);
12 }
13 if (method == "delete")
14 {
15 int id = Convert.ToInt32(context.Request.Form["id"].ToString());
16 DeleteMessage(id, context);
17 }
18 }
19 /// <summary>
20 /// 插入留言
21 /// </summary>
22 /// <param name="message">传递的对象</param>
23 /// <param name="context"></param>
24 public void InsertMessage(MessageClass message, HttpContext context)
25 {
26 string sql = "insert into T_BBS (username,usermessage,userimage,usertime) values ('" + message.UserName + "','" + message.UserMessage + "','" + message.UserImage + "','" + message.UserTime + "')";
27 bool flag= SqlHelper.ExecuteNoReturn(sql);
28 if (flag)
29 {
30 string sqlstring = "select top 1 id from T_BBS order by usertime desc";
31 DataTable dt = SqlHelper.ExcuteSqlReturnTable(sqlstring);
32 context.Response.Write(dt.Rows[0][0].ToString());
33 }
34 else
35 {
36 context.Response.Write("-1");
37 }
38 }
39 /// <summary>
40 /// 删除留言
41 /// </summary>
42 /// <param name="id">特定的id值</param>
43 /// <param name="context"></param>
44 public void DeleteMessage(int id, HttpContext context)
45 {
46 string sql = "delete from T_BBS where id="+id+"";
47 bool flag = SqlHelper.ExecuteNoReturn(sql);
48 if (flag)
49 {
50 context.Response.Write("success");
51 }
52 else
53 {
54 context.Response.Write("error");
55 }
56 }
4.自定义编号
主要思想是绑定AspNetPager的总记录数，每页显示的项数，当前页索引进行一些简单运算即可。
而对新插入的留言进行编号，大体是一样的，就是多给了一个值num，每次插入都num++
代码：
<%#RowsCount - (PageNum-1) *PageSize- Container.ItemIndex%>
