GridView排序、分页

还是先看一下效果吧。

怎么样，是不是很酷？

下面一步说明如何实现：

写一个自定义控件，继承自System.Web.UI.WebControl.GridView,然后对其进行扩展。

分页的实现：

重写OnRowCreate方法，对PagerRow进行特殊处理，清空里面的控件，加入自己的控件。首页，尾页，上一页，下一页的做法是，往PagerRow中添加四个LinkButton,CommandName设成"Page",CommandArgument分别设成"First","Last","Prev","Next".相应的Text或者Image可直接使用PagerSettings属性中的数据。

直接跳转页和每页记录条数的实现相对麻烦一些。加入两个DropDownList控件，往里面填充数据，并在此类中处理它们的OnSelectedIndexChange事件，重置PageIndex和PageSize.

排序图标的实现：

同样在OnRowCreate方法中，对HeaderRow进行特殊处理，可根据SortExpression属性找到当前正在进行排序的列，根据SortDirection属性得到排序的顺序，根据这两个属性往特定的列添加特定的图标。

滚动条的实现：

重写RenderContents方法，改变原有的HTML流布局。如果不重写，原来的布局如下：

 

< Table > //-->GridView

      < tr > //-->PagerRow,当PagerPosition设成Top或TopAndBottom的时候，这一行才会出现

      </ tr >

      < tr > //-->HeaderRow

      </ tr >

      < tr > //-->DataRow

      </ tr >

     ............

      < tr > //-->DataRow

      </ tr >

      < tr > //-->FooterRow

      </ tr >

      < tr > //-->PagerRow(Bottom || TopAndBottom时出现)

</ Table >

重写RenderContents的目的就是把整个GridView分隔成三(两)个Table,第一和第三个Table中放PagerRow部分，中间一个Table放在DIV中，固定DIV的高度，使其出现滚动条，对HeaderRow进行特殊处理，使其不会随滚动条的滚动而消失(方法是:style="top:expression(this.parentNode.parentNode.scrollTop);").然后再用一个Table把这三个Table包起来。重写后布局如下：

 

< Table >

    < tr >

      < td >

        < Table > PagerRow </ Table >

      </ td >

    < tr >

    < tr >

      < td >

        < DIV >

          < Table > DataRow && FooterRow </ Table >

        </ DIV >

      </ td >

     </ tr >

     < tr >

       < td >

          < Table > PagerRow </ Table >

       </ td >

     </ tr >

</ Table >

 

接下来说一下具体实现：

1、新建一个Web Control Library类型的工程,命名为myControls，添加一个类myGridView.cs:代码如下：

using  System;
using  System.Data;
using  System.Configuration;
using  System.Web;
using  System.Collections;
using  System.Web.Security;
using  System.Web.UI;
using  System.Web.UI.WebControls;
using  System.Web.UI.WebControls.WebParts;
using  System.Web.UI.HtmlControls;
using  System.IO;
using  System.ComponentModel;

namespace  CRM2006.GridView
... {
    /**//// <summary>
    /// Summary description for myGridView
    /// </summary>
    ///
    public class CrmGV : System.Web.UI.WebControls.GridView
    ...{
        //private Unit _divheight;
        //private int _offset;
        private bool isPagerCreated = false;
        public CrmGV()
        ...{
        }
        [
        Description("是否启用自定义分页功能"),
        Category("分页"), DefaultValue("false"),Themeable(true)
        ]
        public bool AllowCustomerPagerSettings
        ...{
            get
            ...{
                object o = ViewState["AllowCustomerPagerSettings"];
                return (o != null ? (bool)o : false);
            }
            set
            ...{
                ViewState["AllowCustomerPagerSettings"] = value;
            }
        }
        [Localizable(true), DefaultValue("Current page:"), Themeable(true)]
        public string CurrentPageText
        ...{
            get
            ...{
                object o = ViewState["CurrentPageText"];
                return (o != null ? o.ToString() : "Current page:");
            }
            set
            ...{
                ViewState["CurrentPageText"] = value;
            }
        }
        [Localizable(true), DefaultValue("Jump to page"), Themeable(true)]
        public string JumpToPageText
        ...{
            get
            ...{
                object o = ViewState["JumpToPageText"];
                return (o != null ? o.ToString() : "Jump to page");
            }
            set
            ...{
                ViewState["JumpToPageText"] = value;
            }
        }
        [Localizable(true), DefaultValue("Display{0}records per page"), Themeable(true)]
        public string RecordCountPerPage
        ...{
            get
            ...{
                object o = ViewState["RecordCountPerPage"];
                return (o != null ? o.ToString() : "Display{0}records per page");
            }
            set
            ...{
                ViewState["RecordCountPerPage"] = value;
            }
        }
        [Description("The height of DIV element"), Themeable(true)]
        public virtual Unit DIVHeight
        ...{
            get
            ...{
                object o = ViewState["DIVHeight"];
                return new Unit(o.ToString());
            }
            set
            ...{
                ViewState["DIVHeight"] = value; 
            }
        }
        [Description("Image Url for sort ascending"),Themeable(true), Editor("System.Web.UI.Design.UrlEditor", typeof(System.Drawing.Design.UITypeEditor))]//Editro特性:指定用以改变属性的编辑器
        public string SortAscImageUrl
        ...{
            get 
            ...{
                object o = ViewState["SortImageAsc"];
                return (o != null ? o.ToString() : "");
            }
            set
            ...{
                ViewState["SortImageAsc"] = value;
            }
        }
        [Description("Image Url for sort descending"),Themeable(true), Editor("System.Web.UI.Design.UrlEditor", typeof(System.Drawing.Design.UITypeEditor))]//Editro特性:指定用以改变属性的编辑器
        public string SortDescImageUrl
        ...{
            get
            ...{
                object o = ViewState["SortImageDesc"];
                return (o != null ? o.ToString() : "");
            }
            set
            ...{
                ViewState["SortImageDesc"] = value;
            }
        }
        [Description("OffSet Value of Head Row"), DefaultValue(4), Themeable(true)]
        public int OffSet
        ...{
            get 
            ...{
                object o = ViewState["OffSet"];
                return Convert.ToUInt16(o);
            }
            set 
            ...{
                if (value <= 1)
                    ViewState["OffSet"] = 1;
                else
                    ViewState["OffSet"] = value;
            }
        }
        protected override void OnRowCreated(GridViewRowEventArgs e)
        ...{
            if (e.Row.RowType == DataControlRowType.Pager)
            ...{
                if (AllowCustomerPagerSettings)
                ...{
                        CreateCustomerPager(e.Row);
                }

            }
            else
            ...{
                if (e.Row.RowType == DataControlRowType.Header)
                ...{
                    DisplaySortOrderImages(e.Row);
                }
            }
            base.OnRowCreated(e);
        }
        protected override void OnSorting(GridViewSortEventArgs e)
        ...{
            base.OnSorting(e);
            isPagerCreated = false;
        }

        private void CreateCustomerPager(GridViewRow pager)
        ...{
            pager.Controls[0].Controls.Clear();
            Table tb = new Table();
            tb.Style.Add("width", "100%");
            TableRow row=new TableRow();
            pager.Controls[0].Controls.Add(tb);
            tb.Rows.Add(row);
            TableCell firstCell = new TableCell();
            TableCell secCell = new TableCell();
            TableCell tmpCell = new TableCell();
            firstCell.Attributes["Align"] = "left";
            secCell.Attributes["Align"]="right";
            row.Cells.Add(firstCell);
            row.Cells.Add(secCell);


            tb = new Table();
            firstCell.Controls.Add(tb);
            row = new TableRow();
            tb.Rows.Add(row);

            LinkButton lnk = new LinkButton();
            Label lbl = new Label();
            Image img = new Image();

            if (PageIndex != 0)
            ...{
                //First
                tmpCell = new TableCell();
                tmpCell.Attributes["vAlign"] = "middle";
                lnk.CommandArgument = "First";
                lnk.CommandName = "Page";
                lnk.CausesValidation = false;
                if (PagerSettings.FirstPageImageUrl == String.Empty || PagerSettings.FirstPageImageUrl == null)
                    lnk.Text = (PagerSettings.FirstPageText == String.Empty || PagerSettings.FirstPageText == null ? "First" : PagerSettings.FirstPageText);
                else
                ...{
                    img.ImageUrl = PagerSettings.FirstPageImageUrl;
                    lnk.Text = "";
                    lnk.Controls.Add(img);
                }
                tmpCell.Controls.Add(lnk);
                row.Cells.Add(tmpCell);

                //Preview
                lnk = new LinkButton();
                tmpCell = new TableCell();
                tmpCell.Attributes["vAlign"] = "middle";
                img = new Image();
                lnk.CommandArgument = "Prev";
                lnk.CommandName = "Page";
                lnk.CausesValidation = false;
                if (PagerSettings.PreviousPageImageUrl == String.Empty || PagerSettings.PreviousPageImageUrl == null)
                    lnk.Text = (PagerSettings.PreviousPageText == String.Empty || PagerSettings.PreviousPageText == null ? "Prev" : PagerSettings.PreviousPageText);
                else
                ...{
                    img.ImageUrl = PagerSettings.PreviousPageImageUrl;
                    lnk.Text = "";
                    lnk.Controls.Add(img);
                }
                tmpCell.Controls.Add(lnk);
                row.Cells.Add(tmpCell);
            }

            //Current
            tmpCell = new TableCell();
            tmpCell.Attributes["vAlign"] = "middle";
            if (CurrentPageText == "" || CurrentPageText.IndexOf("{0}") <= 0)
            ...{
                lbl.Text = "Current Page: " + Convert.ToString(PageIndex+1)+"/"+PageCount.ToString()+" ";
            }
            else
            ...{
                lbl.Text = string.Format(CurrentPageText, " " + Convert.ToString(PageIndex + 1) + "/" + PageCount.ToString() + " ");
            }
            tmpCell.Controls.Add(lbl);
            row.Cells.Add(tmpCell);

            if (PageIndex != PageCount - 1)
            ...{
                //Next
                lnk = new LinkButton();
                tmpCell = new TableCell();
                tmpCell.Attributes["vAlign"] = "middle";
                img = new Image();
                lnk.CommandArgument = "Next";
                lnk.CommandName = "Page";
                lnk.CausesValidation = false;
                if (PagerSettings.NextPageImageUrl == String.Empty || PagerSettings.NextPageImageUrl == null)
                    lnk.Text = (PagerSettings.NextPageText == String.Empty || PagerSettings.NextPageText == null ? "Next" : PagerSettings.NextPageText);
                else
                ...{
                    img.ImageUrl = PagerSettings.NextPageImageUrl;
                    lnk.Text = "";
                    lnk.Controls.Add(img);
                }
                tmpCell.Controls.Add(lnk);
                row.Cells.Add(tmpCell);

                //Last
                lnk = new LinkButton();
                tmpCell = new TableCell();
                tmpCell.Attributes["vAlign"] = "middle";
                img = new Image();
                lnk.CommandArgument = "Last";
                lnk.CommandName = "Page";
                lnk.CausesValidation = false;
                if (PagerSettings.LastPageImageUrl == String.Empty || PagerSettings.LastPageImageUrl == null)
                    lnk.Text = (PagerSettings.LastPageText == String.Empty || PagerSettings.LastPageText == null ? "Last" : PagerSettings.LastPageText);
                else
                ...{
                    img.ImageUrl = PagerSettings.LastPageImageUrl;
                    lnk.Text = "";
                    lnk.Controls.Add(img);
                }
                tmpCell.Controls.Add(lnk);
                row.Cells.Add(tmpCell);
            }

            //Jump To
            DropDownList ddl = new DropDownList();
            ddl.AutoPostBack = true;
            //if (!isPagerCreated)
            ddl.SelectedIndexChanged += new EventHandler(CurrentPageIndexChange);
            tmpCell = new TableCell();
            tmpCell.Attributes["vAlign"] = "middle";
            ListItem item = new ListItem();
            string[] tmp;
            for (int i = 0; i < PageCount; i++)
            ...{
                item= new ListItem(Convert.ToString(i + 1), Convert.ToString(i + 1));
                ddl.Items.Add(item);
            }
            ddl.SelectedValue = Convert.ToString(PageIndex+1);
            if (JumpToPageText == string.Empty || JumpToPageText == null)
            ...{
                lbl = new Label();
                lbl.Text = "Jump To Page:";
                tmpCell.Controls.Add(lbl);
                tmpCell.Controls.Add(ddl);
            }
            else
            ...{
                tmp = (String.Format(JumpToPageText, "*")).Split('*');
                if (tmp.Length >= 2)
                ...{
                    lbl = new Label();
                    lbl.Text = tmp[0];
                    tmpCell.Controls.Add(lbl);
                    tmpCell.Controls.Add(ddl);
                    lbl = new Label();
                    lbl.Text = tmp[1];
                    tmpCell.Controls.Add(lbl);
                }
                else
                ...{
                    lbl = new Label();
                    lbl.Text = JumpToPageText;
                    tmpCell.Controls.Add(lbl);
                    tmpCell.Controls.Add(ddl);
                }
            }
            row.Cells.Add(tmpCell);

            tb = new Table();
            row = new TableRow();
            tb.Rows.Add(row);
            secCell.Controls.Add(tb);
            //PageSize

            ddl = new DropDownList();
            tmpCell = new TableCell();
            tmpCell.Attributes["vAlign"] = "middle";
            ddl.AutoPostBack = true;
            item = new ListItem("5", "5");
            ddl.Items.Add(item);
            item = new ListItem("10", "10");
            ddl.Items.Add(item);
            item = new ListItem("20", "20");
            ddl.Items.Add(item);
            item = new ListItem("30", "30");
            ddl.Items.Add(item);
            item = new ListItem("50", "50");
            ddl.Items.Add(item);
            lbl = new Label();
            try
            ...{
                ddl.SelectedValue = this.PageSize.ToString();
            }
            catch
            ...{
                ddl.SelectedValue = "10";
            }
            ddl.SelectedIndexChanged += new EventHandler(ddl_SelectedIndexChanged);
            if (RecordCountPerPage == string.Empty || RecordCountPerPage == null)
            ...{
                RecordCountPerPage = "Display{0}records per page";
            }
            tmp = (String.Format(RecordCountPerPage, "*")).Split('*');
            if (tmp.Length >= 2)
            ...{
                lbl = new Label();
                lbl.Text = tmp[0];
                tmpCell.Controls.Add(lbl);
                tmpCell.Controls.Add(ddl);
                lbl = new Label();
                lbl.Text = tmp[1];
                tmpCell.Controls.Add(lbl);
            }
            else
            ...{
                lbl = new Label();
                lbl.Text = RecordCountPerPage;
                tmpCell.Controls.Add(lbl);
                tmpCell.Controls.Add(ddl);
            }
            row.Cells.Add(tmpCell);
            isPagerCreated = true;
        }
        private void CurrentPageIndexChange(object sender, EventArgs e)
        ...{
            this.PageIndex = int.Parse(((DropDownList)sender).SelectedValue)-1;
            isPagerCreated = false;
        }
        private void DisplaySortOrderImages(GridViewRow dgItem)
        ...{
                for (int i = 0; i < dgItem.Cells.Count; i++)
                ...{
                    if (dgItem.Cells[i].Controls.Count > 0 && dgItem.Cells[i].Controls[0] is LinkButton)
                    ...{
                        string columnExpression = ((LinkButton)dgItem.Cells[i].Controls[0]).CommandArgument;
                        if (columnExpression == SortExpression)
                        ...{
                            string sortImgLoc = (SortDirection == SortDirection.Ascending ? SortAscImageUrl : SortDescImageUrl);
                            Image imgSortDirection = new Image();
                            imgSortDirection.ImageUrl = sortImgLoc;
                            dgItem.Cells[i].Controls.Add(imgSortDirection);
                            break;
                        }
                    }
                }
        }
        private void ddl_SelectedIndexChanged(object sender,EventArgs e)
        ...{
            this.PageSize = int.Parse(((DropDownList)sender).SelectedValue);
            this.PageIndex = 0;
            isPagerCreated = false;
        }
        protected override void RenderContents(HtmlTextWriter writer)
        ...{
            StringWriter sw = new StringWriter();
            HtmlTextWriter hw = new HtmlTextWriter(sw);
            base.RenderContents(hw);
            string strHtml = sw.ToString();

            string strTable = getTable(strHtml);
            bool bHeadPager = this.PagerSettings.Position == PagerPosition.TopAndBottom || this.PagerSettings.Position == PagerPosition.Top;
            strHtml = "<table border='0' cellspacing='0' cellpadding='0'><tr><td>";
            string strPager = "";
            for (int i = 0; i < this.Controls[0].Controls.Count; i++)
            ...{
                GridViewRow row = (GridViewRow)this.Controls[0].Controls[i];
                row.Visible = true;
                StringWriter tmpsw = new StringWriter();
                HtmlTextWriter tmphw = new HtmlTextWriter(tmpsw);
                row.RenderControl(tmphw);
                if (i == 0)
                ...{
                    if (row.RowType == DataControlRowType.Pager)
                    ...{
                        strPager = tmpsw.ToString();
                        if (this.DIVHeight.Value > 0)
                            strHtml += "<table border='0' cellspacing='0' cellpadding='0' width='100%'>" + strPager + "</table></td></tr><tr><td><div style='height:" + this.DIVHeight.ToString() + ";overflow-y:auto;'>" + strTable;
                        else
                            strHtml += "<table border='0' cellspacing='0' cellpadding='0' width='100%'>" + strPager + "</table></td></tr><tr><td><div style='overflow-y:auto;'>" + strTable;
                        isPagerCreated = true;
                    }
                    else
                    ...{
                        if (this.DIVHeight.Value > 0)
                            strHtml += "<div style='overflow-Y:auto;height:" + this.DIVHeight.ToString() + ";'>" + strTable;
                        else
                            strHtml += "<div style='overflow-Y:auto;'>" + strTable;
                        if (row.RowType == DataControlRowType.Header)
                        ...{
                            string HeadStr = tmpsw.ToString();
                            int pos = HeadStr.IndexOf("style="");
                            if (pos > 0)
                            ...{
                                HeadStr = HeadStr.Insert(pos + 7, "position:relative;top:expression(parentNode.parentNode.scrollTop-" + this.OffSet + ");");
                            }
                            else
                            ...{
                                HeadStr = HeadStr.Insert(3, "style="position:relative;top:expression(parentNode.parentNode.scrollTop-" + this.OffSet + ");");
                            }
                            strHtml += HeadStr;
                        }
                        else
                            strHtml += tmpsw.ToString();
                    }
                }
                else
                ...{
                    if (i != this.Controls[0].Controls.Count - 1)
                    ...{
                        if (row.RowType == DataControlRowType.Header)
                        ...{
                            string HeadStr = tmpsw.ToString();
                            int pos = HeadStr.IndexOf("style="");
                            if (pos > 0)
                            ...{
                                HeadStr = HeadStr.Insert(pos + 7, "position:relative;top:expression(parentNode.parentNode.scrollTop-1);");
                            }
                            else
                            ...{
                                HeadStr = HeadStr.Insert(3, "style="position:relative;top:expression(parentNode.parentNode.scrollTop-1);");
                            }
                            strHtml += HeadStr;
                        }
                        else
                            strHtml += tmpsw.ToString();
                    }
                    else
                    ...{
                        if (row.RowType == DataControlRowType.Pager)
                        ...{
                                strHtml += "</table></div></td></tr><tr><td><table border='0' cellspacing='0' cellpadding='0' width='100%'>" + tmpsw.ToString();
                        }
                        else
                        ...{
                            strHtml += tmpsw.ToString();
                        }
                    }
                }
            }
            strHtml += "</table></td></tr></table>";
            writer.Write(strHtml);
            isPagerCreated = false;
        }
        private string getTable(string _html)
        ...{
            int posStart, posEnd;
            posStart = _html.IndexOf("<table", 0);
            posEnd = _html.IndexOf(">", posStart);
            return(_html.Substring(posStart,posEnd-posStart+1));
        }
    }
}

使用方法：

引用：可以把这个工程编译成DLL后，在其他工程中引用此DLL，也可以把这个工程同别的工程放到同一解决方案中，直接引用此工程。

设计：

  往页面中添加控件的两种方法：

  1、Toolbox右键--choose item(s)---.Net Components---browse,选中编译好的myGridView.dll，就会在Toobox出现图标，可直接拖到页面上。

  2、在页面的Source页里添加

<% @ Register Assembly = " myControls "  Namespace = " myControls "  TagPrefix = " control "   %>

就可以在页面中敲入<control:myGridView ID="" runat="server"></control:myGridView>了.