DataGridView分页

        三个控件:DataGridView,BindingNavigator,BindingSource

/**/ /// <summary>
        /// 实现分页定义变量
        /// </summary>
        /// 
         private   int  pageSize  =   0 ;
         private   int  nMax  =   0 ;
         private   int  pageCount  =   0 ;
         private   int  pageCurrent  =   0 ;
         private   int  nCurrent  =   0 ;
        DataSet dst  =   new  DataSet();
        System.Data.DataTable dtInfo  =   new  DataTable(); 
/**/ /// <summary>
        /// 加载数据
        /// </summary>
         private   void  LoadRoomData()
         ... {
            ClearDataGridViewData();
            string connstr = Connectionstr.ConnectionString;
            OleDbConnection oleconn = new OleDbConnection(connstr);
            string sqlstr = "Select RoomTypeName As 客房类型 ,RoomArea As [客房面积(M2)]," +
                                    "RatedBed As [额定床数(张)],RatedCount As [额定人数(人)]," +
                                    "RoomPrice As [客房价格(RMB)],RoomTV As 电视," +
                                    "RoomPhone As 电话,[RoomAir-condition] As 空调 ,RoomToilet As 卫生间  From RoomType";//[RoomAir-condition]中括号不能少
            try
            ...{
                oleconn.Open();
                OleDbDataAdapter oleda = new OleDbDataAdapter(sqlstr, oleconn);
                //DataSet ds = new DataSet();
                //oleda.Fill(ds);
                oleda.Fill(dst);
                oleconn.Close();
                dtInfo = dst.Tables[0];
                if (dst.Tables .Count >0 && dst.Tables[0].Rows.Count > 0)
                ...{
                    InitDataSet();
                    DatagridviewSetColumnWidth();
                }
                else return;
                //dgvRoomType.DataSource = ds.Tables[0];
            }
            catch (Exception exp)
            ...{
                MessageBox.Show(exp.ToString ());
            }
        }
  private   void  InitDataSet()
         ... {
            //pageSize = 1;
            IniFile inif = new IniFile();
            pageSize = int.Parse(inif.IniReadValue("DataGridView", "pagesize"));
            nMax = dtInfo.Rows.Count;
            pageCount = nMax / pageSize;
            if ((nMax % pageSize) > 0)
                pageCount++;
            pageCurrent = 1;//当前页面数从1开始
            nCurrent = 0;
            LoadData();
        }
         private   void  LoadData()
         ... {
            int nStartPos = 0;
            int nEndPos = 0;
            System.Data.DataTable dtTemp = dtInfo.Clone();//克隆
            if (pageCurrent == pageCount)
                nEndPos = nMax;
            else
                nEndPos = pageSize * pageCurrent;
            nStartPos = nCurrent;
            bdnCountpage.Text = pageCount.ToString();
            bdnCurrentpage.Text =Convert .ToString ( pageCurrent);

            //从原数据源复制记录行
            for (int i = nStartPos; i < nEndPos; i++)
            ...{
                dtTemp.ImportRow(dtInfo.Rows[i]);
                nCurrent++;
            }
            BdsInfo.DataSource = dtTemp;
            BdnInfo.BindingSource = BdsInfo;
            dgvRoomType.DataSource = BdsInfo;
            
        }

         private   void  BdnInfo_ItemClicked( object  sender, ToolStripItemClickedEventArgs e)
         ... {
            if (e.ClickedItem.Text == "上一页")
            ...{
                pageCurrent--;
                if (pageCurrent <= 0)
                ...{
                    MessageBox.Show("已经是第一页了，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“上页”查看");
                    return;
                }
                else
                ...{
                    nCurrent = pageSize * (pageCurrent - 1);
                }
                LoadData();
            }
        }

         private   void  bdnCurrentpage_KeyPress( object  sender, KeyPressEventArgs e)
         ... {
            if (e.KeyChar == 13)
            ...{
                string pattern = @"^d+$";
                if (Regex.IsMatch(bdnCurrentpage.Text.Trim(), pattern))
                ...{
                    if (int.Parse(bdnCurrentpage.Text) > pageCount || int.Parse(bdnCurrentpage.Text) <= 0)
                    ...{
                        MessageBox.Show("已经超出显示范围");
                        return;
                    }
                    else
                    ...{
                        pageCurrent = int.Parse(bdnCurrentpage.Text);
                        nCurrent = pageSize * (pageCurrent - 1);
                    }
                    LoadData();
                }
            }
        }