如何在自定义的继承自GridView的控件中加入PagerTemplate行。

Question

我想实现自定义分页，但不想每个页面都重复去写代码，因此决定扩展GridView空间，问题是如何动态创建PagerTemplate并加入到GridView中
主要是想实现不同的翻页方式。我不想用现成的开发好的，未开源的控件。

Answer 1

简单说就是如何让自定义的继承自GridView的控件，实现自定义翻页

Answer 2

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Text;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;namespace Saga.LivePortal.CustomControl
{
    [ToolboxData("<{0}:MyGridView runat=server></{0}:MyGridView>")]
    public class MyGridView : System.Web.UI.WebControls.GridView, IPostBackEventHandler, IPostBackDataHandler
    {
        /// <summary>
        /// 
        /// </summary>
        public MyGridView()
        {
            base.SelectedRowStyle.CssClass = "SelectedItem";
            base.RowStyle.CssClass = "GridItem";
            base.AlternatingRowStyle.CssClass = "GridAltItem";
            base.HeaderStyle.CssClass = "GridHeader";
            base.EditRowStyle.CssClass = "SelectedItem";
            base.RowStyle.Height = 20;
        }
        /// <summary>
        /// 
        /// </summary>
        public delegate void OnReBindData();
        /// <summary>
        /// 
        /// </summary>
        public event OnReBindData ReBindData;
        /// <summary>
        /// const string stands for the navigate-to-first-page command sent from the grid
        /// </summary>
        private const string NAVIGATE_FIRST = "NAV_FIRST";
        /// <summary>
        /// const string stands for the navigate-to-last-page command sent from the grid
        /// </summary>
        private const string NAVIGATE_LAST = "NAV_LAST";
        /// <summary>
        /// const string stands for the navigate-to-previous-page command sent from the grid
        /// </summary>
        private const string NAVIGATE_PREVIOUS = "NAV_PREVIOUS";
        /// <summary>
        /// const string stands for the navigate-to-next-page command sent from the grid
        /// </summary>
        private const string NAVIGATE_NEXT = "NAV_NEXT";        private const string PAGESIZE_CONTROL = "PAGESIZE_CONTROL";        private bool showPageNavigator = true;        public bool ShowPageNavigator
        {
            get
            {
                return showPageNavigator;
            }
            set
            {
                showPageNavigator = value;
            }
        }        #region Override GridView methods
        public override void RenderControl(HtmlTextWriter writer)
        {
            try
            {
                writer.Write("<table border=\"0\" class=\"table_dark_inside\" width=\"" + this.Width.ToString() + "\" cellpadding=\"0\" cellspacing=\"0\">");
                writer.Write("<tr><td align=\"left\" width=\"100%\">");
                base.Render(writer);
                writer.Write("</td></tr>");
                if (this.showPageNavigator)
                {
                    writer.Write("<tr><td>");
                    DrawPager(writer);
                    writer.Write("</td></tr>");
                }
                writer.Write("</table>");
            }
            catch (Exception e)
            {
                System.Diagnostics.Debug.Write(e);
            }
        }        protected override void OnRowCreated(GridViewRowEventArgs e)
        {
            try
            {
                if (e.Row.RowType == DataControlRowType.Header)
                {
                    // Call the GetSortColumnIndex helper method to determine
                    // the index of the column being sorted.
                    int sortColumnIndex = GetSortColumnIndex();                    if (sortColumnIndex != -1)
                    {
                        // Call the AddSortImage helper method to add
                        // a sort direction image to the appropriate
                        // column header. 
                        AddSortImage(sortColumnIndex, e.Row);
                    }
                }
                base.OnRowCreated(e);
            }
            catch (Exception ex)
            {
                System.Diagnostics.Debug.Write(ex);
            }
        }        /// <summary>
        /// This is a helper method used to determine the index of the
        /// column being sorted. If no column is being sorted, -1 is returned.
        /// </summary>
        /// <returns></returns>
        private int GetSortColumnIndex()
        {
            // Iterate through the Columns collection to determine the index
            // of the column being sorted.
            try
            {
                foreach (DataControlField field in this.Columns)
                {
                    // judge the current sort column ,if first create ,then return columns[0]
                    if ((field.SortExpression == this.SortExpression) && (field.SortExpression != ""))
                    {
                        return this.Columns.IndexOf(field);
                    }
                }
            }
            catch (Exception ex)
            {
                System.Diagnostics.Debug.Write(ex);
            }
            return -1;
        }        /// <summary>
        /// This is a helper method used to add a sort direction
        /// image to the header of the column being sorted.
        /// </summary>
        /// <param name="columnIndex"></param>
        /// <param name="headerRow"></param>
        private void AddSortImage(int columnIndex, GridViewRow headerRow)
        {
            try
            {
                // Create the sorting image based on the sort direction.
                Image sortImage = new Image();
                if (this.SortDirection == SortDirection.Ascending)
                {
                    sortImage.ImageUrl = "~/Images/LivePortal/up.gif";
                    sortImage.AlternateText = "Ascending Order";
                }
                else
                {
                    sortImage.ImageUrl = "~/Images/LivePortal/down.gif";
                    sortImage.AlternateText = "Descending Order";
                }
                // Add the image to the appropriate header cell.
                headerRow.Cells[columnIndex].Controls.Add(sortImage);
            }
            catch (Exception e)
            {
                System.Diagnostics.Debug.Write(e);
            }
        }        protected override void OnInit(EventArgs e)
        {
            try
            {
                this.PagerSettings.Visible = false;
                this.AutoGenerateColumns = false;
                base.OnInit(e);
                RegisterControlAndScript();
                Page.RegisterRequiresPostBack(this);
            }
            catch (Exception ex)
            {
                System.Diagnostics.Debug.Write(ex);
            }
        }        protected override void OnLoad(EventArgs e)
        {
            base.OnLoad(e);
        }
        #endregion

Answer 3

接上
        /// <summary>
        /// 
        /// </summary>
        /// <param name="writer"></param>
        protected virtual void DrawPager(HtmlTextWriter writer)
        {
            try
            {
                writer.Write("<table border=\"0\"  cellpadding=\"0\" cellspacing=\"0\" width=\"" + this.Width.ToString() + " \">");
                writer.Write("<tr height=\"25\" valign=\"middle\">");
                writer.Write("<td align=\"right\" width=\"100%\" class=\"GridPager\">Total Page(s): " + this.PageCount + "&nbsp;");
                writer.Write("Current Page: <font color=red>" + (this.PageIndex + 1) + "</font>&nbsp;");
                writer.Write(GetCommandLink(NAVIGATE_FIRST));
                writer.Write(GetCommandLink(NAVIGATE_PREVIOUS));
                writer.Write(GetCommandLink(NAVIGATE_NEXT));
                writer.Write(GetCommandLink(NAVIGATE_LAST));
                writer.Write("Display ");
                writer.Write(GetPageSizeSelect());
                writer.Write("per page");
                writer.Write("</td></tr></table>");
            }
            catch (Exception e)
            {
                System.Diagnostics.Debug.Write(e);
            }
        }
        /// <summary>
        /// this method registers two hidden fields and a script block on the page
        /// </summary>
        private void RegisterControlAndScript()
        {
            try
            {
                System.Web.UI.Control pageControl = this.Page.FindControl(PAGESIZE_CONTROL);
                if (pageControl == null)
                {
                    this.Page.ClientScript.RegisterHiddenField(PAGESIZE_CONTROL, "");
                }                if (!this.Page.ClientScript.IsClientScriptBlockRegistered("ChangePageSizeScript"))
                {
                    StringBuilder scriptBuilder = new StringBuilder();
                    scriptBuilder.Append("<script language='JavaScript'>\n");
                    scriptBuilder.Append("function __SetPageCmd(pageSize)\n");
                    scriptBuilder.Append("{\n");
                    scriptBuilder.Append("\n var ParamTag = document.getElementById('" + PAGESIZE_CONTROL + "');\n");
                    scriptBuilder.Append("\n ParamTag.value=pageSize;\n");
                    scriptBuilder.Append("}\n");
                    scriptBuilder.Append("</script>");
                    string script = scriptBuilder.ToString();
                    this.Page.ClientScript.RegisterClientScriptBlock(typeof(string), "ChangePageSizeScript", script);
                }
            }
            catch (Exception e)
            {
                System.Diagnostics.Debug.Write(e);
            }
        }
        /// <summary>
        /// this method returns the PostBackEventReference of the Grid in its destination page
        /// </summary>
        /// <returns>PostBack Event Reference</returns>
        private string GetPostBackRef(string paramCMD)
        {
            return Page.ClientScript.GetPostBackEventReference(this, paramCMD) + ";";
        }        private string GetCommandLink(string command)
        {
            string cmdLink = "";
            try
            {
                switch (command)
                {
                    case NAVIGATE_FIRST:
                        cmdLink = "<a class=\"PagerHyperlinkStyle\" href=\"javascript: " + GetPostBackRef("Page$First") + "\">|&lt;</a>";
                        break;
                    case NAVIGATE_PREVIOUS:
                        cmdLink = "<a class=\"PagerHyperlinkStyle\" href=\"javascript: " + GetPostBackRef("Page$Prev") + "\">&lt;</a>";
                        break;
                    case NAVIGATE_NEXT:
                        cmdLink = "<a class=\"PagerHyperlinkStyle\" href=\"javascript: " + GetPostBackRef("Page$Next") + "\">&gt;</a>";
                        break;
                    case NAVIGATE_LAST:
                        cmdLink = "<a class=\"PagerHyperlinkStyle\" href=\"javascript: " + GetPostBackRef("Page$Last") + "\">&gt;|</a>";
                        break;
                }
            }
            catch (Exception ex)
            {
                System.Diagnostics.Debug.Write(ex);
            }
            return cmdLink + "&nbsp;";
        }        /// <summary>
        /// Write Select Page Size List
        /// </summary>
        /// <returns>string</returns>
        private string GetPageSizeSelect()
        {
            string selectString = "<select class=\"select\" onchange=\"javascript: __SetPageCmd(this.options[this.selectedIndex].text);" + GetPostBackRef("PageSizeParam") + "\" id=\"SelectPage\">";
            try
            {
                switch (base.PageSize)
                {
                    case 5:
                        selectString += "<option selected>5</option><option>10</option><option>15</option>";
                        break;
                    case 10:
                        selectString += "<option>5</option><option selected>10</option><option>15</option>";
                        break;
                    case 15:
                        selectString += "<option>5</option><option>10</option><option  selected>15</option>";
                        break;
                    default:
                        selectString += "<option>5</option><option selected>10</option><option>15</option>";
                        break;
                }
                selectString += "</select>&nbsp";
            }
            catch (Exception ex)
            {
                System.Diagnostics.Debug.Write(ex);
            }
            return selectString;
        }
        #region IPostBackEventHandler Members        void IPostBackEventHandler.RaisePostBackEvent(string eventArgument)
        {
            try
            {
                if (ReBindData != null)
                {
                    ReBindData();
                }
                if (eventArgument == "Page$Next")
                {
                    if ((this.PageIndex + 1) == this.PageCount)
                    {
                        return;
                    }
                }
                if (eventArgument == "Page$Prev")
                {
                    if ((this.PageIndex + 1) == 1)
                    {
                        return;
                    }
                }
                base.RaisePostBackEvent(eventArgument);
            }
            catch (Exception e)
            {
                System.Diagnostics.Debug.Write(e);
            }
        }        #endregion        #region IPostBackDataHandler Members        public bool LoadPostData(string postDataKey, System.Collections.Specialized.NameValueCollection postCollection)
        {
            try
            {
                int pageSize = Convert.ToInt32(postCollection[PAGESIZE_CONTROL]);
                base.PageSize = pageSize;
            }
            catch (Exception ex)
            {
                System.Diagnostics.Debug.Write(ex);
            }
            return true;
        }        public void RaisePostDataChangedEvent()
        {        }        #endregion
    }
}