Csharp windowform bindingNavigator,bindingSource,DataGridView簡單分頁：首頁,上一頁,下一頁,末頁

   /// <summary>
    /// 塗聚文 2011-10-24 （參考相關網絡和書藉資料）
    /// 締友計算機信息技術有限公司
    ///C# Winform 簡單分頁： 首頁，上一頁，下一頁，末頁
    /// </summary>
    public partial class FormDataGridViewPage : Form
    {
        /// <summary>
        /// 每页显示行数
        /// </summary>
        int pageSize = 0; 
        /// <summary>
        /// 总记录数
        /// </summary>
        int nMax = 0;        
        /// <summary>
        /// 页数＝总记录数/每页显示行数
        /// </summary>
        int pageCount = 0;   
        /// <summary>
        /// 当前页号
        /// </summary>
        int pageCurrent = 0;  
        /// <summary>
        /// 当前记录行
        /// </summary>
        int nCurrent = 0;     

        DataSet ds = new DataSet();
        DataTable dtInfo = new DataTable();
        AdministrativeAreaListBLL administrativeAreaListBLL = new AdministrativeAreaListBLL();
        AdministrativeAreaListInfo administrativeAreaListInfo = new AdministrativeAreaListInfo();
        FormOperatingStringInfo formOperatingStringInfo = new FormOperatingStringInfo();

        /// <summary>
        /// 
        /// </summary>
        public FormDataGridViewPage()
        {
            InitializeComponent();
        }
        /// <summary>
        /// 
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void FormDataGridViewPage_Load(object sender, EventArgs e)
        {
            dtInfo = administrativeAreaListBLL.SelectAdministrativeAreaListDataTable();
            InitDataSet();
        }  
        /// <summary>
        /// 用首页数据填充
        /// 塗聚文
        /// 締友計算機信息技術有限公司
        ///C# Winform 簡單分頁： 首頁，上一頁，下一頁，末頁
        /// </summary>
        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();
        }
        /// <summary>
        /// 用末頁數據填育
        /// 塗聚文
        /// 締友計算機信息技術有限公司
        ///C# Winform 簡單分頁： 首頁，上一頁，下一頁，末頁
        /// </summary>
        private void EndDataSetPage()
        {
            pageSize = 20;      //设置页面行数
            nMax = dtInfo.Rows.Count;
            pageCount = (nMax / pageSize);    //计算出总页数  
            int rou = nMax % pageSize;
            if (rou > 0)
            {
                nCurrent = nMax - (nMax % pageSize);//不是正好整除页码，取余数页
                pageCount++;
            }
            else
            {
                nCurrent = nMax - pageSize;
            }
   
            pageCurrent = pageCount;
            LoadData();
        }
        /// <summary>
        /// 填充DataGridView
        /// 塗聚文
        /// 締友計算機信息技術有限公司
        ///C# Winform 簡單分頁： 首頁，上一頁，下一頁，末頁
        /// </summary>
        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(); //共多少頁
            txtCurrentPage.Text = Convert.ToString(pageCurrent);//當前頁


            //从元数据源复制记录行
            for (int i = nStartPos; i < nEndPos; i++)
            {
                dtTemp.ImportRow(dtInfo.Rows[i]);
                nCurrent++;
            }
            bindingSourceInfo.DataSource = dtTemp;
            bindingNavigatorInfo.BindingSource = bindingSourceInfo;
            DataGridViewInfo.DataSource = bindingSourceInfo;
        }
        /// <summary>
        /// 点击的选择页操作
        /// 涂聚文
        /// 締友計算機信息技術有限公司
        ///C# Winform 簡單分頁： 首頁，上一頁，下一頁，末頁
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void bindingNavigatorInfo_ItemClicked(object sender, ToolStripItemClickedEventArgs e)
        {
            if (e.ClickedItem.Text == "关闭")
            {
                this.Close();
            }
            if (e.ClickedItem.Text == "首页")
            {
                pageCurrent = 1;
                pageSize = 20;
                InitDataSet();
            }
            if (e.ClickedItem.Text == "末页")
            {
                EndDataSetPage();
            }
            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();

            }
        }
}