DataGrid自定义分页控件

      网上关于 DataGrid 自定义的分页控件很多，参照一些例子，做了一些优化，主要优点是使用方便，且控件中用ViewState保存了DataGrid需要绑定的数据，免去在绑定DataGrid时额外的处理，开发环境VS.NET2003。

      在调用页面引入分页控件命名控件后，定义protected PeterSun.Control.WebControl.Ascx.GridPager GridPager1，页面中调用的主要代码如下。

GridPager1.RelatedDataGridID = this.DataGrid1.ID;   //设置关联的DataGrid的ID属性,必须
GridPager1.RelatedDataSource = dt;   //设置数据源,必须
GridPager1.IsShowSummary = true;    //设置是否显示共有多少页,每页多少行信息
GridPager1.IsShowJumping = false;   //设置是否显示跳转到某页

       

      分页控件的详细代码，用ViewState保存了控件的属性信息，这里可以进一步扩展，如设置分页信息样式，显示哪些信息，等等。

    public class GridPager : System.Web.UI.UserControl
    ...{
        protected System.Web.UI.WebControls.LinkButton LBtnFirst;
        protected System.Web.UI.WebControls.LinkButton LBtnPrev;
        protected System.Web.UI.WebControls.LinkButton LBtnNext;
        protected System.Web.UI.WebControls.LinkButton LBtnLast;
        protected System.Web.UI.WebControls.DropDownList ddlPagerNavigate;
        protected System.Web.UI.WebControls.Label lblTip;  
        protected System.Web.UI.WebControls.Label lblPagerInfo;   //分页描述信息,默认显示

        private System.Web.UI.WebControls.DataGrid relatedDataGrid;  //要分页的DataGrid
        private DataTable relatedDataSource;  //绑定DataGrid的数据源
        private string relatedDataGridID; //DataGrid控件ID
        private bool isShowSummary = true;   //是否显示分页描述,默认显示
        private bool isShowJumping = true;   //是否显示跳转,默认显示

        private void Page_Load(object sender, System.EventArgs e)
        ...{
            // Put user code to initialize the page here
            if(Page.IsPostBack)
            ...{
                this.PrepareParameters();
            }
        }

        Web Form Designer generated code#region Web Form Designer generated code
        override protected void OnInit(EventArgs e)
        ...{
            //
            // CODEGEN: This call is required by the ASP.NET Web Form Designer.
            //
            InitializeComponent();
            base.OnInit(e);
        }
        
        /**//// <summary>
        ///        Required method for Designer support - do not modify
        ///        the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        ...{
            this.LBtnFirst.Click += new System.EventHandler(this.LBtnPager_Click);
            this.LBtnPrev.Click += new System.EventHandler(this.LBtnPager_Click);
            this.LBtnNext.Click += new System.EventHandler(this.LBtnPager_Click);
            this.LBtnLast.Click += new System.EventHandler(this.LBtnPager_Click);
            this.ddlPagerNavigate.SelectedIndexChanged += new System.EventHandler(this.ddlPagerNavigate_SelectedIndexChanged);
            this.Load += new System.EventHandler(this.Page_Load);

        }
        #endregion

        分页控件公开属性#region 分页控件公开属性
        /**//// <summary>
        /// 与分页控件关联的DataGrid控件ID
        /// </summary>
        public string RelatedDataGridID
        ...{
            get
            ...{ 
                return relatedDataGridID;
            }
            set
            ...{
                relatedDataGridID = value ;
                ViewState["DataGridID"] = value;
                //根据relatedDataGridID从父页面中获取需要关联的DataGrid控件
                this.relatedDataGrid = (DataGrid)this.Parent.FindControl(relatedDataGridID);
            }
        }

        /**//// <summary>
        /// 与DataGrid绑定的数据源
        /// </summary>
        public DataTable RelatedDataSource
        ...{
            get
            ...{
                return relatedDataSource ;
            }
            set
            ...{
                relatedDataSource = value ;
                relatedDataGrid.DataSource=relatedDataSource;
                ViewState["DataSource"] = relatedDataSource;
            }
        }

        /**//// <summary>
        /// 是否显示分页描述信息
        /// </summary>
        public bool IsShowSummary
        ...{
            get
            ...{
                return isShowSummary ;
            }
            set
            ...{
                isShowSummary = value ;
                ViewState["IsShowSummary"] = isShowSummary;
            }
        }

        /**//// <summary>
        /// 是否显示跳转页面
        /// </summary>
        public bool IsShowJumping
        ...{
            get
            ...{
                return isShowJumping ;
            }
            set
            ...{
                isShowJumping = value ;
                ViewState["IsShowJumping"] = isShowJumping;
            }
        }
         #endregion

        分页控件方法#region 分页控件方法
        /**//// <summary>
        /// 准备参数,DataGrid和DataTable
        /// </summary>
        private void PrepareParameters()
        ...{
            if(ViewState["DataGridID"] != null)
            ...{
                this.relatedDataGridID = Convert.ToString(ViewState["DataGridID"]);
                this.relatedDataGrid = (DataGrid)this.Parent.FindControl(this.relatedDataGridID);
            }    
            if(ViewState["DataSource"] != null)
            ...{
                this.relatedDataSource = (DataTable)ViewState["DataSource"];
                this.relatedDataGrid.DataSource = this.relatedDataSource;
            }
            if(ViewState["IsShowSummary"] != null)
            ...{
                this.isShowSummary = (bool)ViewState["IsShowSummary"];
            }
            if(ViewState["IsShowJumping"] != null)
            ...{
                this.isShowJumping = (bool)ViewState["IsShowJumping"];
            }
        }

        /**//// <summary>
        /// 生成跳转页列表
        /// </summary>
        private void PopulatePageNavigate()
        ...{
            this.ddlPagerNavigate.Items.Clear() ;
            for(int i = 0 ;i <relatedDataGrid.PageCount ; i ++)
            ...{
                this.ddlPagerNavigate.Items.Add("第" + Convert.ToString(i+1) + "页");
            }
            this.ddlPagerNavigate.SelectedIndex =this.relatedDataGrid.CurrentPageIndex;
        }

        /**//// <summary>
        /// 执行DataGrid绑定,并更改控件的状态信息
        /// </summary>
        public override void DataBind()
        ...{
            try
            ...{
                this.relatedDataGrid.DataBind() ;
            }
            catch
            ...{
                try
                ...{
                    this.relatedDataGrid.CurrentPageIndex-= 1;
                }
                catch
                ...{
                    this.relatedDataGrid.CurrentPageIndex = 0;
                }
                
                this.relatedDataGrid.DataBind() ;
            }
            
            this.lblPagerInfo.Text = "第" + Convert.ToString(relatedDataGrid.CurrentPageIndex+1) + "/" + Convert.ToString(relatedDataGrid.PageCount) + "页," + relatedDataGrid.PageSize + "条/页,共" + Convert.ToString(relatedDataSource.Rows.Count ) + "条" ;

            if(relatedDataGrid.CurrentPageIndex == 0)
            ...{
                this.LBtnFirst.Enabled = false ;
                this.LBtnPrev.Enabled  = false ;
            }
            else
            ...{
                this.LBtnFirst.Enabled = true ;
                this.LBtnPrev.Enabled = true ;
            }

            if(relatedDataGrid.CurrentPageIndex == (relatedDataGrid.PageCount -1))
            ...{
                this.LBtnNext.Enabled = false ;
                this.LBtnLast.Enabled = false ;
            }
            else
            ...{
                this.LBtnNext.Enabled = true ;
                this.LBtnLast.Enabled = true ;
            }

            //控制是否隐藏部分控件
            this.lblPagerInfo.Visible = this.isShowSummary;
            this.lblTip.Visible = this.isShowJumping;
            this.ddlPagerNavigate.Visible = this.isShowJumping;


            //绑定页码下拉列表
            this.PopulatePageNavigate();
        }

        /**//// <summary>
        /// 单击翻页按钮控制翻页
        /// </summary>
        private void LBtnPager_Click(object sender, System.EventArgs e)
        ...{
            LinkButton btn = (LinkButton)sender;
            switch(btn.CommandName)
            ...{
                case "First":
                    this.relatedDataGrid.CurrentPageIndex = 0;
                    break;
                case "Prev":
                    if(relatedDataGrid.CurrentPageIndex > 0)
                    ...{
                        relatedDataGrid.CurrentPageIndex = relatedDataGrid.CurrentPageIndex - 1 ;
                    }
                    break;
                case "Next":
                    if(relatedDataGrid.CurrentPageIndex < relatedDataGrid.PageCount - 1)
                    ...{
                        relatedDataGrid.CurrentPageIndex = relatedDataGrid.CurrentPageIndex  + 1 ;
                    }
                    break;
                case "Last":
                    relatedDataGrid.CurrentPageIndex = relatedDataGrid.PageCount -1 ;
                    break;
            }

            this.DataBind();
        }

        /**//// <summary>
        /// 跳转页下拉列表控制分页
        /// </summary>
        private void ddlPagerNavigate_SelectedIndexChanged(object sender, System.EventArgs e)
        ...{
            if(this.ddlPagerNavigate.SelectedIndex > 0)
            ...{
                relatedDataGrid.CurrentPageIndex = this.ddlPagerNavigate.SelectedIndex;
                this.DataBind();
            }
        }
        #endregion
    }

 

      附上分页效果图，下一步的目标是把用户控件改写成复合控件，那样就方便图形化设置属性了