简单分页页码功能

using System;
using System.Data;
using System.Configuration;
using System.Web;
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.Text;

/// <summary>
/// PageList 的摘要说明
/// </summary>
public class PageList
{
    public static string GetPage(string url,int num,int c_p)
    {
        StringBuilder str=new StringBuilder();
        int stnum = 8 + c_p;
        if (num<8)
        {
            stnum=num;
        }
        else
        {
            stnum=8+c_p;
        }
        for (int i = c_p - 4; i <= stnum; i++)
        {
            if (i == c_p)
            {
                str.Append(i + " ");
            }
            else
            {
                str.Append("<a href='" + url + "&page=" + i + "'>" + i + "</a>" + " ");
            }

        }
        str.Append("..." + "<a href='" + url + "&page=" + num + "'>" + num + "</a>" + " ");

        return str.ToString();
     } 

    

 /// <summary>
    ///
    /// </summary>
    /// <param name="total">总记录数</param>
    /// <param name="per">每页记录数</param>
    /// <param name="page">当前页码</param>
    /// <param name="query_string">Url参数</param>
    /// <returns></returns>
    public static string pagination(int total, int per, int page, string query_string)
    {
        int allpage = 0;
        int next = 0;
        int pre = 0;
        int startcount = 0;
        int endcount = 0;
        string pagestr = "";

        if (page < 1) { page = 1; }
        //计算总页数
        if (per != 0)
        {
            allpage = (total / per);
            allpage = ((total % per) != 0 ? allpage + 1 : allpage);
            allpage = (allpage == 0 ? 1 : allpage);
        }
        next = page + 1;
        pre = page - 1;
        startcount = (page + 5) > allpage ? allpage - 9 : page - 4;//中间页起始序号
        //中间页终止序号
        endcount = page < 5 ? 10 : page + 5;
        if (startcount < 1) { startcount = 1; } //为了避免输出的时候产生负数，设置如果小于1就从序号1开始
        if (allpage < endcount) { endcount = allpage; }//页码+5的可能性就会产生最终输出序号大于总页码，那么就要将其控制在页码数之内
        pagestr = "共" + allpage + "页&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;";

        pagestr += page > 1 ? "<a href=\"" + query_string + "?page=1\">首页</a>&nbsp;&nbsp;<a href=\"" + query_string + "?page=" + pre + "\">上一页</a>" : "首页 上一页";
        //中间页处理，这个增加时间复杂度，减小空间复杂度
        for (int i = startcount; i <= endcount; i++)
        {
            pagestr += page == i ? "&nbsp;&nbsp;<font color=\"#ff0000\">" + i + "</font>" : "&nbsp;&nbsp;<a href=\"" + query_string + "?page=" + i + "\">" + i + "</a>";
        }
        pagestr += page != allpage ? "&nbsp;&nbsp;<a href=\"" + query_string + "?page=" + next + "\">下一页</a>&nbsp;&nbsp;<a href=\"" + query_string + "?page=" + allpage + "\">末页</a>" : " 下一页 末页";

        return pagestr;
    }

}