// 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();

           }

     }