控件扩展 - GridView分页及数据源为空

    /// <summary>
    /// 重写分页，及数据源为空时显示表头
    /// </summary>
    public class GridviewExpand : System.Web.UI.WebControls.GridView
    {
        #region 扩展属性

        /// <summary>
        /// Gridview 分页是否重写
        /// </summary>
        public ThisPagerType ExpendPagerType
        {
            get
            {
                return (ViewState["PagerType"] != null ? (ThisPagerType)ViewState["PagerType"] : ThisPagerType.ChangeStyle);
            }
            set
            {
                ViewState["PagerType"] = value;
            }
        }

        /// <summary>
        /// 数据源为空时，是否显示表头（true:显示）
        /// </summary>
        public Boolean ExpendEmptyHeader
        {
            get
            {
                return _enableEmptyContentRender;
            }
            set
            {
                _enableEmptyContentRender = value;
            }
        }

        public enum ThisPagerType
        {
            //样式不变
            Regular = 0,
            //样式变化
            ChangeStyle = 1
        }
        #endregion

        /// <summary>
        /// 重写InitializePager 添加想要的样式
        /// </summary>
        /// <param name="row"></param>
        /// <param name="columnSpan"></param>
        /// <param name="pagedDataSource">数据源</param>
        protected override void InitializePager(GridViewRow row, int columnSpan, PagedDataSource pagedDataSource)
        {
            if (ExpendPagerType == ThisPagerType.Regular)
            {
                //如果样式是Regular，即不为扩展样式
                base.InitializePager(row, columnSpan, pagedDataSource);
            }
            else
            {
                TableCell cell_1 = InitPageCell(pagedDataSource);

                row.Cells.Add(cell_1);
                row.Cells[0].ColumnSpan = Columns.Count;
                row.Cells[0].HorizontalAlign = HorizontalAlign.Right;
                this.Controls[0].Controls.AddAt(0, row);
            }
        }


        #region TabCell 分页单元格样式：记录数：1~10/30  页数：1/2 上一页 下一页 转到 __ 页


        //填写跳转到多少页
        TextBox page = new TextBox();

        //链接 
        LinkButton PageTo = new LinkButton();

        #region 分页信息生成

        /// <summary>
        /// 记录数：1~10/22  
        /// </summary>
        /// <param name="rowCount"></param>
        /// <returns></returns>
        private Label RecordInfo(int rowCount)
        {
            Label label = new Label();
            int currentPageFirstRow = ((PageIndex * PageSize) + 1);
            int currentPageLastRow = 0;
            int lastPageRemainder = rowCount % PageSize;

            if (lastPageRemainder == 0)
            {
                lastPageRemainder = PageSize;
            }
            currentPageLastRow = (PageCount == PageIndex + 1) ? (currentPageFirstRow + lastPageRemainder - 1) : (currentPageFirstRow + PageSize - 1);
            label.Text = String.Format("记录数: {0}~{1}/{2}  ", currentPageFirstRow, currentPageLastRow, rowCount);
            return label;
        }

        /// <summary>
        /// 页数：1/10
        /// </summary>
        /// <returns></returns>
        private Label PageInfo()
        {
            Label pageInfo = new Label();
            pageInfo.Text = "页数: " + (PageIndex + 1).ToString() + "/" + PageCount.ToString() + "  ";
            return pageInfo;
        }

        /// <summary>
        /// 导航按键【首页 上一页 下一页 末页】
        /// </summary>
        /// <param name="type"></param>
        /// <returns></returns>
        private LinkButton NavigateLink(NavigateType type)
        {
            LinkButton button = new LinkButton();

            switch (type)
            {
                case NavigateType.first:
                    {
                    }
                    break;
                case NavigateType.prev:
                    {
                        button.Text = "上一页";
                        button.CommandArgument = string.Format("{0}", (PageIndex - 1));
                        button.Enabled = (PageIndex > 0);
                    }
                    break;
                case NavigateType.next:
                    {
                        button.Text = "下一页";
                        button.CommandArgument = string.Format("{0}", (PageIndex + 1));
                        button.Enabled = (PageIndex < (PageCount - 1));
                    }
                    break;
                case NavigateType.last:
                    {
                    }
                    break;
            }
            button.Click += new EventHandler(navigate_Click);
            return button;
        }

        private enum NavigateType
        {
            first,
            prev,
            next,
            last
        }

        #endregion

        #region 跳转事件

        protected virtual void navigate_Click(object sender, EventArgs e)
        {
            OnPageIndexChanging(new GridViewPageEventArgs(int.Parse(((LinkButton)sender).CommandArgument)));
        }

        //跳转到第几页
        protected virtual void PageTo_Click(object sender, EventArgs e)
        {
            if (page.Text.Trim() == "")
            {
                page.Text = "0";
            }
            else
            {
                try
                {
                    int.Parse(page.Text.Trim());
                }
                catch (Exception ex)
                {

                    page.Text = "0";
                }
            }
            if (int.Parse(page.Text.Trim()) < 1)
            {
                page.Text = "0";
            }
            else
            {
                int num = int.Parse(page.Text.Trim());
                num--;
                page.Text = num.ToString();

            }

            PageTo.CommandArgument = page.Text.Trim();


            OnPageIndexChanging(new GridViewPageEventArgs(int.Parse(((LinkButton)sender).CommandArgument)));

            //矫正显示页数
            if (int.Parse(page.Text.Trim()) < 1)
            {
                page.Text = "1";
            }
            else if (int.Parse(page.Text.Trim()) > PageCount)
            {
                page.Text = PageCount.ToString();
            }
            else
            {
                page.Text = (PageIndex + 1).ToString();
            }

        }
        #endregion

        /// <summary>
        /// 跳转文本框 样式为 pagetxt
        /// </summary>
        /// <param name="pagedDataSource"></param>
        /// <returns></returns>
        protected TableCell InitPageCell(PagedDataSource pagedDataSource)
        {
            //分页单元格
            TableCell cell_1;

            #region 设置属性

            //记录数 1~2/3
            Label recordinfo = RecordInfo(pagedDataSource.DataSourceCount);

            //页数 1/10
            Label pageinfo = PageInfo();

            //上一页
            LinkButton prev = NavigateLink(NavigateType.prev);

            //下一页
            LinkButton next = NavigateLink(NavigateType.next);

            //转到 __ 页
            PageTo.Text = "转到";
            PageTo.Click += new System.EventHandler(PageTo_Click);

            page.Attributes.Add("class", "pagetxt");
            page.Attributes.Add("style", "width:20px");

            Label pagelabel = new Label();
            pagelabel.Text = "页";

            #endregion

            #region 设置位置

            cell_1 = new TableCell();

            //记录数
            cell_1.Controls.Add(recordinfo);

            //页数
            cell_1.Controls.Add(pageinfo);

            //上一页
            cell_1.Controls.Add(prev);

            //间隔
            cell_1.Controls.Add(new LiteralControl("&nbsp;&nbsp;"));

            //下一页
            cell_1.Controls.Add(next);

            cell_1.Controls.Add(new LiteralControl("&nbsp;&nbsp;"));
            cell_1.Controls.Add(PageTo);

            cell_1.Controls.Add(new LiteralControl("&nbsp;"));
            cell_1.Controls.Add(page);

            cell_1.Controls.Add(new LiteralControl("&nbsp;"));
            cell_1.Controls.Add(pagelabel);

            #endregion;

            return cell_1;
        }
        #endregion

        #region 数据源为空时

        private Boolean _enableEmptyContentRender = true;

        /// <summary>
        /// 为空时输出内容
        /// </summary>
        /// <param name="writer"></param>
        protected virtual void RenderEmptyContent(System.Web.UI.HtmlTextWriter writer)
        {
            Table table = new Table();
            table.CopyBaseAttributes(this);

            #region  表头TR : 限制表头中无控件，隐藏列HeaderText需="";

            //行 tr
            TableRow tr = new TableRow();

            //显示原有表头th
            foreach (System.Web.UI.WebControls.DataControlField field in this.Columns)
            {
                //lms中隐藏列的表头为空
                if (field.HeaderText != "")
                {
                    System.Web.UI.WebControls.TableHeaderCell cell = new System.Web.UI.WebControls.TableHeaderCell();
                    cell.Text = field.HeaderText;
                    tr.Cells.Add(cell);
                }
            }
            table.Rows.Add(tr);
            #endregion

            #region 内容行,样式 empty

            //为空时 信息
            TableRow row = new TableRow();

            System.Web.UI.WebControls.TableCell msgCell = new System.Web.UI.WebControls.TableCell();

            if (this.EmptyDataTemplate != null)
            {
                this.EmptyDataTemplate.InstantiateIn(msgCell);
            }
            else
            {
                this.EmptyDataText = "暂无相关信息";//td
                msgCell.Text = this.EmptyDataText;
            }
            table.Rows.Add(row);

            msgCell.CssClass = "empty";
            msgCell.ColumnSpan = this.Columns.Count;
            row.Cells.Add(msgCell);
            #endregion

            table.CssClass = this.CssClass;//样式的继承
            table.RenderControl(writer);
        }

        protected override void Render(System.Web.UI.HtmlTextWriter writer)
        {
            if (this._enableEmptyContentRender == true && (this.Rows.Count == 0 || this.Rows[0].RowType == System.Web.UI.WebControls.DataControlRowType.EmptyDataRow))
            {
                RenderEmptyContent(writer);
            }
            else
            {
                base.Render(writer);

            }
        }
        #endregion

    }

 

效果图如下