ASP.NET 主页分页都可以想出来。但是后台编写的啊???

在bdnInfo控件中添加几个用于选择页面的lable和botton，如上图所示。
     设计时：
     1、定义几个所需的公有成员：
                 int pageSize = 0;     //每页显示行数
        int nMax = 0;         //总记录数
        int pageCount = 0;    //页数＝总记录数/每页显示行数
        int pageCurrent = 0;   //当前页号
        int nCurrent = 0;      //当前记录行
        DataSet ds = new DataSet();
        DataTable dtInfo = new DataTable();
    2、在窗体载入事件中，从数据源读取记录到DataTable中：
                 string strConn = "SERVER=127.0.0.1;DATABASE=NORTHWIND;UID=SA;PWD=ULTRATEL";   //数据库连接字符串
            SqlConnection conn = new SqlConnection(strConn);
            conn.Open();
            string strSql = "SELECT * FROM CUSTOMERS";
            SqlDataAdapter sda = new SqlDataAdapter(strSql,conn);
            sda.Fill(ds,"ds");
            conn.Close();
            dtInfo = ds.Tables[0];
            InitDataSet();
      3、用当前页面数据填充DataGridView
           private void InitDataSet()
        {
            pageSize = 20;      //设置页面行数
            nMax = dtInfo.Rows.Count;

            pageCount=(nMax/pageSize);    //计算出总页数

            if ((nMax % pageSize) > 0) pageCount++;

            pageCurrent = 1;    //当前页数从1开始
            nCurrent = 0;       //当前记录数从0开始

            LoadData();
        }private void LoadData()
        {
            int nStartPos = 0;   //当前页面开始记录行
            int nEndPos = 0;     //当前页面结束记录行

            DataTable dtTemp = dtInfo.Clone();   //克隆DataTable结构框架

            if (pageCurrent == pageCount)
                nEndPos = nMax;
            else
                nEndPos = pageSize * pageCurrent;

            nStartPos = nCurrent;

            lblPageCount.Text = pageCount.ToString();
            txtCurrentPage.Text = Convert.ToString(pageCurrent);

            //从元数据源复制记录行
            for (int i = nStartPos; i < nEndPos; i++)
            {
                dtTemp.ImportRow(dtInfo.Rows[i]);
                nCurrent++;
            }
            bdsInfo.DataSource = dtTemp;
            bdnInfo.BindingSource = bdsInfo;
            dgvInfo.DataSource = bdsInfo;
        }        4、菜单响应事件：
  private void bdnInfo_ItemClicked(object sender, ToolStripItemClickedEventArgs e)
        {
            if (e.ClickedItem.Text == "关闭")
            {
                this.Close();
            }
            if (e.ClickedItem.Text == "上一页")
            {
                pageCurrent--;
                if (pageCurrent <= 0)
                {
                    MessageBox.Show("已经是第一页，请点击“下一页”查看！");
                    return;
                }
                else
                {
                    nCurrent = pageSize * (pageCurrent - 1);
                }

                LoadData();
            }
            if (e.ClickedItem.Text == "下一页")
            {
                pageCurrent++;
                if (pageCurrent > pageCount)
                {
                    MessageBox.Show("已经是最后一页，请点击“上一页”查看！");
                    return;
                }
                else
                {
                   nCurrent=pageSize*(pageCurrent-1);
                }
                LoadData();
            }
        }