ANF的分页组件修改版

using System;
using System.Collections.Generic;
using System.Text.RegularExpressions;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Web.UI;
using System.Web;
using System.Text;
using System.IO;
using AspNetForums.Components;
using AspNetForums.Components.Enumerations;

namespace AspNetForums.Controls
{
    public class PagerEventArgs : EventArgs
    {
        public PagerEventArgs()
        { }

        public PagerEventArgs(int index)
        {
            newPageIndex = index;
        }

        public int NewPageIndex
        {
            get { return newPageIndex; }
        }

        int newPageIndex;
    }
    /// <summary>
 /// Summary description for Pager.
 /// </summary>
 public class Pager : Label, INamingContainer
 {
  #region Member variables

  HyperLink previousLink;
  HyperLink nextLink;
  HyperLink firstLink;
  HyperLink lastLink;
  HyperLink[] pagingHyperLinks;
        bool urlPaging = true;

        LinkButton previousButton;
        LinkButton nextButton;
        LinkButton firstButton;
        LinkButton lastButton;
        LinkButton[] pageingButtons;

        HtmlInputText txtCustom;
        Button button;

        public Pager()
        {
        }

        #endregion

        PagerType pagerType = PagerType.None;
        public PagerType PagerType
        {
            get { return pagerType; }
            set { pagerType = value; }
        }

  #region Render functions

        /// <summary>
        /// This event handler adds the children controls and is resonsible
        /// for determining the template type used for the control.
        /// </summary>
        protected override void CreateChildControls()
        {
            //AutoBindForTotalRecordsValue();

            Controls.Clear();

            if (UrlPaging)
            {
                AddPageLinks();
                AddPreviousNextLinks();
                AddFirstLastLinks();
            }
            else
            {
                AddPageButtons();
                AddPreviousNextButton();
                AddFirstLastButton();
            }

           AddCustomPager();
           Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "customPager", GetScripts(), true);
        }
        String GetScripts()
        {
            StringBuilder sb = new StringBuilder();
            sb.Append(@"
                function go(page){
                    if(event.keyCode==13||event.srcElement.value=='Go'){
                     var strUrl=location.href.toLowerCase();
                     strUrl=strUrl.replace(/(\&)?pageindex=\d+/gi,'');
                     if(location.search=='')
                            strUrl=strUrl+'?pageindex='+page;
                        else
                            strUrl=strUrl+'&pageindex='+page;
                     location.href=strUrl;
                        return false;
                    }
                }");
            return sb.ToString();
        }

        void AddCustomPager()
        {
            txtCustom = new HtmlInputText();
            txtCustom.ID = "txtCustom";
            txtCustom.EnableViewState = false;
            txtCustom.Style.Add("width", "20px;");
            txtCustom.Style.Add("border", "1px solid");
            txtCustom.Attributes.Add("onkeyup", "this.value=this.value.replace(/[^0-9]/gi,'');");
            Controls.Add(txtCustom);

            button = new Button();
            button.ID = "button";
            button.Text = "Go";
            button.Style.Add("width", "22px");
            if (UrlPaging)
            {
                txtCustom.Attributes.Add("onkeydown", "return go(this.value);");
                button.UseSubmitBehavior = false;
                button.OnClientClick = "return go(document.getElementById('"+txtCustom.ClientID+"').value);";
            }
            else
            {
                button.Click += new EventHandler(LinkButton_Click);
            }
            Controls.Add(button);
        }

        protected override void Render(HtmlTextWriter writer)
  {
   int totalPages = CalculateTotalPages();

   // Do we have data?
   //
   if (totalPages <= 1)
    return;

            if (ShowCurrentPage)
                RenderCurrentPage(writer);

   AddAttributesToRender(writer);

   // Render the paging buttons
   //
   writer.AddAttribute(HtmlTextWriterAttribute.Class, this.CssClass, false);

   // Render the first button
   //
   RenderFirst(writer);

   // Render the previous button
   //
   RenderPrevious(writer);
           
   // Render the page button(s)
   //
   RenderPagingButtons(writer);

   // Render the next button
   //
   RenderNext(writer);

   // Render the last button
   //
   RenderLast(writer);

            RenderCustom(writer);

  }
        void RenderCustom(HtmlTextWriter writer)
        {
            writer.Write("    跳转到:");
            txtCustom.RenderControl(writer);
            button.RenderControl(writer);
        }

        void RenderCurrentPage(HtmlTextWriter writer)
        {
            writer.Write(string.Format(this.CurrentPageStringFormat, (this.PageIndex + 1), this.CalculateTotalPages(), this.TotalRecords));
        }

  void RenderFirst(HtmlTextWriter writer)
  {
   int totalPages = CalculateTotalPages();

   if ((PageIndex >= 3) && (totalPages > 5))
   {
                if (UrlPaging)
                {
                    firstLink.RenderControl(writer);
                }
                else
                {
                    firstButton.RenderControl(writer);
                }

    LiteralControl l = new LiteralControl("&nbsp;...&nbsp;");
    l.RenderControl(writer);
   }
  }

  void RenderLast(HtmlTextWriter writer)
  {
   int totalPages = CalculateTotalPages();

   if (((PageIndex + 3) < totalPages) && (totalPages > 5))
   {
    LiteralControl l = new LiteralControl("&nbsp;...&nbsp;");
    l.RenderControl(writer);

                if (UrlPaging)
                {
                    lastLink.RenderControl(writer);
                }
                else
                {
                    lastButton.RenderControl(writer);
                }
   }
  }

  void RenderPrevious(HtmlTextWriter writer)
  {
   Literal l;

   if (HasPrevious)
   {
                if (UrlPaging)
                {
                    previousLink.RenderControl(writer);
                }
                else
                {
                    previousButton.RenderControl(writer);
                }

    l = new Literal();
    l.Text = "&nbsp;";
    l.RenderControl(writer);
   }
  }

  void RenderNext(HtmlTextWriter writer)
  {
   Literal l;

   if (HasNext)
   {

    l = new Literal();
    l.Text = "&nbsp;";
    l.RenderControl(writer);

                if (UrlPaging)
                {
                    nextLink.RenderControl(writer);
                }
                else
                {
                    nextButton.RenderControl(writer);
                }
   }
  }

  void RenderButtonRange(int start, int end, HtmlTextWriter writer)
  {
   for (int i = start; i < end; i++)
   {
    // Are we working with the selected index?
    //
    if (PageIndex == i)
    {
     // Render different output
     //
     Literal l = new Literal();
     l.Text = "<b>" + (i + 1).ToString() + "</b>";

     l.RenderControl(writer);
    }
    else
    {
                    if (UrlPaging)
                    {
                        pagingHyperLinks[i].RenderControl(writer);
                    }
                    else
                    {
                        pageingButtons[i].RenderControl(writer);
                    }
    }
    if ( i < (end - 1) )
     writer.Write(" ");
   }
  }

  void RenderPagingButtons(HtmlTextWriter writer)
  {
   int totalPages;

   // Get the total pages available
   //
   totalPages = CalculateTotalPages();

   // If we have <= 5 pages display all the pages and exit
   //
   if ( totalPages <= 5)
   {
    RenderButtonRange(0, totalPages, writer);
   }
   else
   {
    int lowerBound = (PageIndex - 2);
    int upperBound = (PageIndex + 3);

    if (lowerBound <= 0)
     lowerBound = 0;

    if (PageIndex == 0)
     RenderButtonRange(0, 5, writer);

    else if (PageIndex == 1)
     RenderButtonRange(0, (PageIndex + 4), writer);

    else if (PageIndex < (totalPages - 2))
     RenderButtonRange(lowerBound, (PageIndex + 3), writer);

    else if (PageIndex == (totalPages - 2))
     RenderButtonRange((totalPages - 5), (PageIndex + 2), writer);

    else if (PageIndex == (totalPages - 1))
     RenderButtonRange((totalPages - 5), (PageIndex + 1), writer);
   }
  }

  #endregion

  #region ControlTree functions

  void AddPageLinks()
  {
   // First add the lower page buttons
   //
   pagingHyperLinks = new HyperLink[CalculateTotalPages()];

   // Create the buttons and add them to
   // the Controls collection
   //
   for (int i = 0; i < pagingHyperLinks.Length; i++)
   {
    pagingHyperLinks[i] = new HyperLink();
    pagingHyperLinks[i].EnableViewState = false;
    pagingHyperLinks[i].Text = (i + 1).ToString();
    pagingHyperLinks[i].ID = (i + 1).ToString();
    pagingHyperLinks[i].NavigateUrl = CreatePagerURL((i + 1).ToString());
    Controls.Add(pagingHyperLinks[i]);
   }
  }

        void AddPageButtons()
        {
            pageingButtons = new LinkButton[CalculateTotalPages()];
            for (int i = 0; i < pageingButtons.Length; i++)
            {
                pageingButtons[i] = new LinkButton();
                pageingButtons[i].EnableViewState = false;
                pageingButtons[i].Text = (i + 1).ToString();
                pageingButtons[i].ID = (i + 1).ToString();
                pageingButtons[i].CommandArgument = i.ToString();
                pageingButtons[i].Click += new EventHandler(LinkButton_Click);
                Controls.Add(pageingButtons[i]);
            }
        }

  void AddFirstLastLinks()
  {
   int start = 1;
   firstLink = new HyperLink();
   firstLink.ID = "First";
   firstLink.Text = this.FirstPageText;
   firstLink.NavigateUrl = CreatePagerURL(start.ToString());
   Controls.Add(firstLink);

   int last = CalculateTotalPages();
   lastLink = new HyperLink();
   lastLink.ID = "Last";
   lastLink.Text = this.LastPageText;
   lastLink.NavigateUrl = CreatePagerURL(last.ToString());
   Controls.Add(lastLink);
  }
        void AddFirstLastButton()
        {
            int start = 0;
            firstButton = new LinkButton();
            firstButton.ID = "First";
            firstButton.Text = this.FirstPageText;
            firstButton.CommandArgument = start.ToString();
            firstButton.Click+=new EventHandler(LinkButton_Click);
            Controls.Add(firstButton);

            lastButton = new LinkButton();
            lastButton.ID = "Last";
            lastButton.Text = this.LastPageText;
            lastButton.CommandArgument = (CalculateTotalPages()-1).ToString();
            lastButton.Click+=new EventHandler(LinkButton_Click);
            Controls.Add(lastButton);
        }

  void AddPreviousNextLinks()
  {
   int previous;
   
   if (this.PageIndex < 2)
    previous = 1;
   else
    previous = this.PageIndex;

   previousLink = new HyperLink();
   previousLink.ID = "Prev";
   previousLink.Text = this.PreviousPageText;
   previousLink.NavigateUrl = CreatePagerURL(previous.ToString());
   Controls.Add(previousLink);

   int next = this.PageIndex + 2;
   nextLink = new HyperLink();
   nextLink.ID = "Next";
   nextLink.Text = this.NextPageText;
   nextLink.NavigateUrl = CreatePagerURL(next.ToString());
   Controls.Add(nextLink);
  }
        void AddPreviousNextButton()
        {
            int previous;
            if (this.PageIndex < 2)
                previous = 1;
            else
                previous = this.PageIndex-1;

            previousButton = new LinkButton();
            previousButton.ID = "Prev";
            previousButton.Text = this.PreviousPageText;
            previousButton.CommandArgument = previous.ToString();
            previousButton.Click+=new EventHandler(LinkButton_Click);
            Controls.Add(previousButton);

            int next = previous + 2;
            nextButton = new LinkButton();
            nextButton.ID = "Next";
            nextButton.Text = this.NextPageText;
            nextButton.CommandArgument = next.ToString();
            nextButton.Click+=new EventHandler(LinkButton_Click);
            Controls.Add(nextButton);
        }
  #endregion

  #region Properties
       
        /// <summary>
        /// Override how this control handles its controls collection
        /// </summary>
        public override ControlCollection Controls
        {
            get
            {
                EnsureChildControls();
                return base.Controls;
            }

        }

  private bool HasPrevious
  {
   get
   {
    if (PageIndex > 0)
     return true;

    return false;
   }
  }

  private bool HasNext
  {
   get
   {
    if (PageIndex + 1 < CalculateTotalPages() )
     return true;

    return false;
   }
  }

        private bool IsBoundUsingDataSourceID
        {
            get
            {
                return (this.DataSourceID.Length > 0);
            }
        }

        bool showCurrentPage = true;
        public bool ShowCurrentPage
        {
            get { return showCurrentPage; }
            set { showCurrentPage = value; }
        }

        public bool UrlPaging
        {
            get { return urlPaging; }
            set { urlPaging = value; }
        }

        string currentPageStringFormat="";// = "Page {0} of {1} ({2} records) &nbsp;-&nbsp; ";
        /// <summary>
        /// CurrentPageStringFormat is the text that should be used to dispaly current page number.
        /// It has been provided to allow custom formatting.
        /// There are 2 implicit params that you may use: page index and total pages number.
        /// Its implicit format is: "Page {0} of {1} ({2} records) &nbsp;-&nbsp;" and it makes use of both params.
        /// </summary>
        public string CurrentPageStringFormat
        {
            get { return currentPageStringFormat; }
            set { currentPageStringFormat = value; }
        }

        string dataSourceID = string.Empty;
        public string DataSourceID
        {
            get
            {
                object obj1 = ViewState["DataSourceID"];
                if (obj1 != null)
                {
                    dataSourceID = (string)obj1;
                }

                return dataSourceID;
            }
            set
            {
                dataSourceID = value;

                ViewState["DataSourceID"] = dataSourceID;               
            }
        }
 
        string firstPageText = "&lt;&lt;";
        public string FirstPageText
        {
            get { return firstPageText; }
            set { firstPageText = value; }
        }

        string lastPageText = "&gt;&gt;";
        public string LastPageText
        {
            get { return lastPageText; }
            set { lastPageText = value; }
        }

        string previousPageText = "&lt;";
        public string PreviousPageText
        {
            get { return previousPageText; }
            set { previousPageText = value; }
        }

        string nextPageText = "&gt;";
        public string NextPageText
        {
            get { return nextPageText; }
            set { nextPageText = value; }
        }

        int _pageIndex = 0;
        public virtual int PageIndex
        {
            get
            {
                if (!UrlPaging)
                {
                    if (ViewState["PageIndex"] == null)
                        return 0;
                    else
                        return Convert.ToInt32(ViewState["PageIndex"]);
                }
                else
                {
                    _pageIndex = ForumContext.Current.PageIndex;

                    if (_pageIndex < 0)
                        return 0;
                    else
                        return _pageIndex;
                }
            }
            set
            {
                ViewState["PageIndex"] = value;
                _pageIndex = value;
            }
        }

        public virtual int PageSize
        {
            get
            {
               
                int pageSize = Convert.ToInt32(ViewState["PageSize"]);

                SiteSettings settings = Globals.GetSiteSettings();

                if (pageSize <= 0)
                {
                    switch (pagerType)
                    {
                        case PagerType.ShowPost:
                            return settings.PostsPerPage;
                        case PagerType.ShowForum:
                            return settings.ThreadsPerPage;
                        case PagerType.None:
                            return settings.ThreadsPerPage;
                    }
                }

                return pageSize;
            }
            set
            {
                ViewState["PageSize"] = value;
            }

        }

        public int TotalRecords
        {
            get
            {
                return Convert.ToInt32(ViewState["TotalRecords"]);
            }
            set
            {
                ViewState["TotalRecords"] = value;
            }
        }

  #endregion

  #region Helper methodss

  protected virtual string CreatePagerURL(string pageIndex)
  {
            HttpContext context = HttpContext.Current;

            SiteUrls siteUrl = new SiteUrls();
            switch (pagerType)
            {
                case PagerType.ShowPost:
                    int postID = 0;
                    try
                    {
                        postID = int.Parse(context.Request.QueryString["PostID"]);
                    }
                    catch { }
                    return siteUrl.Post(postID, int.Parse(pageIndex));
                case PagerType.ShowForum:
                    int forumID = 0;
                    try{
                        forumID = int.Parse(context.Request.QueryString["ForumID"]);
                    }
                    catch {}
                    return siteUrl.Forum(forumID, int.Parse(pageIndex));
                case PagerType.LatestTopics:
                    return siteUrl.PostsLatest(int.Parse(pageIndex));

                case PagerType.NotReadTopics:
                    return siteUrl.PostsNotRead(int.Parse(pageIndex));

                case PagerType.UnansweredTopics:
                    return siteUrl.PostsUnanswered(int.Parse(pageIndex));

                case PagerType.ActiveTopics:
                    return siteUrl.PostsActive(int.Parse(pageIndex));

                //case PagerType.PrivateMessages:
                //    return siteUrl.

                case PagerType.None:
                    if (context.Request.Url.AbsoluteUri.IndexOf("?") == -1)
                    {
                        return context.Request.Url.AbsoluteUri.ToString() + "?PageIndex=" + pageIndex;
                    }
                    else
                    {
                        if (context.Request.Url.AbsoluteUri.ToLower().IndexOf("pageindex=") == -1)
                            return context.Request.Url.AbsoluteUri.ToString() + "&PageIndex=" + pageIndex;
                        else
                        {
                            //SiteUrls siteUrls = new SiteUrls();
                            //siteUrls.th
                            return Regex.Replace(context.Request.Url.AbsoluteUri.ToLower().ToString(), @"pageindex=(\d+\.?\d*|\.\d+)", "PageIndex=" + pageIndex);
                        }
                    }

            }

            return "";          
  }

  /// <summary>
  /// Static that caculates the total pages available.
  /// </summary>
  ///
  public virtual int CalculateTotalPages()
  {
   int totalPagesAvailable;

   if (TotalRecords == 0)
    return 0;

   // First calculate the division
   //
   totalPagesAvailable = TotalRecords / PageSize;

   // Now do a mod for any remainder
   //
   if ((TotalRecords % PageSize) > 0)
    totalPagesAvailable++;

   return totalPagesAvailable;
  }
  #endregion
        public event EventHandler<PagerEventArgs> PageIndexChanged;
        protected void OnPageIndexChanged(PagerEventArgs e)
        {
            this.PageIndex = e.NewPageIndex;
            EventHandler<PagerEventArgs> eventHandler = PageIndexChanged;
            if (eventHandler != null)
                eventHandler(this, e);
        }
        void LinkButton_Click(object sender, EventArgs e)
        {
            int pageIndex = 0;
            try
            {
                if (sender is LinkButton)
                {
                    pageIndex = Convert.ToInt32((sender as LinkButton).CommandArgument);
                }
                else if (sender is Button)
                {
                    pageIndex = Convert.ToInt32(txtCustom.Value)-1;
                }
                else
                {
                    pageIndex = Convert.ToInt32((sender as TextBox).Text);
                }
            }
            catch (InvalidCastException ex)
            {
                pageIndex = 0;
            }
            PagerEventArgs pe = new PagerEventArgs(pageIndex);
            OnPageIndexChanged(pe);
        }

    }
}