.net搜索查询并实现分页实例

前台：


代码如下:

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="分页.aspx.cs" Inherits="分页练习.分页" %>
<!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>
    <table>
        <tr><td>
            <asp:TextBox ID="txtKey" runat="server"></asp:TextBox>
            <asp:ImageButton ID="btnQuery" runat="server" onclick="btnQuery_Click" ImageUrl="~/images/0.jpg" Width="20" Height="20" />
            <asp:Label ID="Label1" runat="server" Text=""></asp:Label>
            </td>
        </tr>
        <tr><td><div id="divResult" runat="server"></div></td></tr>
        <tr><td>
            <asp:LinkButton ID="btnFirst" runat="server" onclick="btnFirst_Click">第一页</asp:LinkButton>
            <asp:LinkButton ID="btnBefore" runat="server" onclick="btnBefore_Click">上一页</asp:LinkButton>
            <asp:LinkButton ID="btnNext" runat="server" onclick="btnNext_Click">下一页</asp:LinkButton>
            <asp:LinkButton ID="btnLast" runat="server" onclick="btnLast_Click">最后一页</asp:LinkButton>
            </td>
        </tr>
    </table>
    </div>
    </form>
</body>
</html>

后台：

代码如下:

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;
using System.Text;
namespace 分页练习
{
    public partial class 分页 : System.Web.UI.Page
    {
        int pagesize = 3;
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                //ViewState虽然是声明在函数内部，看似是局部变量，但是在类中的其他函数中也可以直接使用
                ViewState["pageindex"] = 1;
                LoadData();
                Count();
            }
        }
        //搜索查询
        private void LoadData()
        {
            string strcon = "Data Source=PC-DLL;Initial Catalog=News;Persist Security Info=True;User Id=sa;Password=linlin";
            SqlConnection conn = new SqlConnection(strcon);
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = conn;
            cmd.CommandText = "SELECT TOP(@pagesize) * FROM T_News WHERE(NewsTitle LIKE @newskey OR NewsContent LIKE @newskey) AND Id NOT IN(SELECT TOP ((@pageindex-1)*@pagesize) Id FROM T_News WHERE NewsTitle LIKE @newskey OR NewsContent LIKE @newskey ORDER BY Id )ORDER BY Id";
            cmd.Parameters.AddWithValue("@newskey", "%" + txtKey.Text + "%");
            cmd.Parameters.AddWithValue("@pagesize",pagesize);
            cmd.Parameters.AddWithValue("@pageindex", Convert.ToInt32(ViewState["pageindex"]));
            SqlDataAdapter adapter = new SqlDataAdapter(cmd);
            DataTable dt = new DataTable();
            adapter.Fill(dt);
            StringBuilder sb1 = new StringBuilder();
            sb1.Append("<table>");
            sb1.Append("<tr><td>标题</td><td>内容</td><td>创建时间</td></tr>");
            foreach (DataRow row in dt.Rows)
            {
                sb1.Append("<tr>");
                sb1.Append("<td>" + row["NewsTitle"].ToString() + "</td>");
                sb1.Append("<td>" + row["NewsContent"].ToString() + "</td>");
                sb1.Append("<td>" + row["CreateTime"].ToString() + "</td>");
                sb1.Append("</tr>");
            }
            sb1.Append("</table>");
            divResult.InnerHtml = sb1.ToString();
        }
        private void Count()
        {
            string strcon = "Data Source=PC-DLL;Initial Catalog=News;Persist Security Info=True;User Id=sa;Password=linlin";
            SqlConnection conn = new SqlConnection(strcon);
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = conn;
            cmd.CommandText = "SELECT COUNT(*) FROM T_News WHERE NewsTitle LIKE @newskey OR NewsContent LIKE @newskey";
            cmd.Parameters.AddWithValue("@newskey", "%" + txtKey.Text + "%");
            conn.Open();
            int totalcount = Convert.ToInt32(cmd.ExecuteScalar());
            if (totalcount % pagesize == 0)
            {
                ViewState["pagelastindex"] = totalcount / pagesize;
            }
            else
            {
                ViewState["pagelastindex"] = totalcount / pagesize + 1;
            }
            cmd.Dispose();
            conn.Dispose();
        }
        //第一页
        protected void btnFirst_Click(object sender, EventArgs e)
        {
            ViewState["pageindex"] = 1;
            LoadData();
        }
        //上一页
        protected void btnBefore_Click(object sender, EventArgs e)
        {

int pageindex = Convert.ToInt32(ViewState["pageindex"]);
            if (pageindex > 1)
            {  
                pageindex--;
                ViewState["pageindex"] = pageindex;
                LoadData();
            } 
        }
        //下一页
        protected void btnNext_Click(object sender, EventArgs e)
        {
            int pageindex = Convert.ToInt32(ViewState["pageindex"]);
            if (pageindex < Convert.ToInt32(ViewState["pagelastindex"]))
            {
                pageindex++;
                ViewState["pageindex"] = pageindex;
                LoadData();
            } 
        }
        //最后一页
        protected void btnLast_Click(object sender, EventArgs e)
        {
            ViewState["pageindex"] = ViewState["pagelastindex"];
            LoadData();
        }
        protected void btnQuery_Click(object sender, ImageClickEventArgs e)
        {
            Count();
            LoadData();
        }
    }
}