长文章分页显示类，暂不支持文章中带图片，仅纯文字

1. [文件] article.php

<?php
/**
 * 文章分页类
 *
 * @author ymz [e-mail]
 * @version 1.3
 */

/*
For example:

$curPage = $_GET['page'];
$totalPage = $curPage;
$objArt = new article($article,40,14);
$objArt->setWrapSign("<br/>");
$objArt->setMore('more','this is complete url address.');
$part = $objArt->getOnePage($curPage,$totalPage);
echo $part;
*/

class article {
    var $string = '';
    var $curPart = '';
    var $allLine = 0;
    var $totalPage = null;
    var $curPage = 1;
    var $curLine = 1;
    var $onePageLine = 10;
    var $oneLineWord = 40;
    var $arrArticle = array();
    var $wrapSign = "\n";
    var $more = null;

    function article($str,$oneLineWord = 40,$onePageLine = 10)
    {
        $this->string = $str;
        $this->oneLineWord = $oneLineWord;
        $this->onePageLine = $onePageLine;
    }

    //设置换行符
    function setWrapSign($str)
    {
        $this->wrapSign = $str;
    }

    //是否显示更多
    function setMore($str,$link)
    {
        $this->more = array('word' => $str,'url' => $link);
    }

    //设置总页面、总行数，构造文章数组
    function getAllPage($str='')
    {
        if ($str)
            $this->string = $str;
        $this->allLine = 0;

        $arrayStr = explode($this->wrapSign,$this->string);
        foreach ($arrayStr as $num => $part) {
            $length = $this->strlen($part);
            if ($length > $this->oneLineWord) {
                $tmp_line = ceil($length / $this->oneLineWord);
            } else {
                $tmp_line = 1;
            }
            $this->allLine += $tmp_line;
            $this->arrArticle[$num] = array(
                'lines' => $tmp_line,
                'string' => $part
            );
        }
        $this->totalPage = ceil($this->allLine / $this->onePageLine);
        return $this->totalPage;
    }

    //获取某页数据
    function getOnePage($page,&$totalPage)
    {
        if (is_null($this->totalPage))
            $this->getAllPage();
        $totalPage = $this->totalPage;
        !$page && $page = 1;
        $page > $totalPage && $page = $totalPage;
        $this->curPage = $page;

        $startLine = ($page - 1) * $this->onePageLine + 1;
        $endLine = $startLine + $this->onePageLine - 1;
        $tmp_line = 0; $tmp_str = ''; $key = count($this->arrArticle);
        foreach ($this->arrArticle as $k => $part) {
            $tmp_line += $part['lines'];
            
            if ($startLine > 1 && $tmp_line - $part['lines'] < $startLine && $tmp_line >= $startLine)
            {
                $tmp_str = '';
                $startWord = ($startLine - ($tmp_line - $part['lines'] + 1)) * $this->oneLineWord;
                $startWord = $startWord < 0 ? 0 : $startWord;
                $needWord = $this->oneLineWord * $this->onePageLine;
                $part['string'] = $this->substr($part['string'],$startWord,$needWord);

                if ($tmp_line == $endLine)
                    $this->_setLastLine($part['string']);
            }
            else if ($tmp_line == $startLine - 1)
            {
                $tmp_str = '';
                continue;
            }
            else if ($tmp_line > $endLine)
            {
                $needWord = ($endLine - ($tmp_line - $part['lines'])) * $this->oneLineWord;
                $part['string'] = $this->substr($part['string'],0,$needWord);

                $this->_setLastLine($part['string']);
            }

            $tmp_str .= $part['string'];
            if ($tmp_line < $endLine && $k + 1 < $key)
                $tmp_str .= '<br/>';
            else if ($tmp_line >= $endLine || $k + 1 == $key) {
                $this->_setLastLine($part['string']);
                break;
            }
        }
        $this->curPart = $tmp_str;
        if (!is_null($this->more)) $this->_setMore();
        return $this->curPart;
    }

    //设置最后一行数据
    function _setLastLine($str)
    {
        $this->getAllPage($str);
        $startWord = ($this->allLine - 1) * $this->oneLineWord;
        $this->lastLine = $this->substr($str,$startWord,$this->oneLineWord);
    }

    //获取最后一行数据
    function getLastLine()
    {
        return $this->lastLine;
    }

    //对 more 进行设置
    function _setMore()
    {
        $length = $this->strlen($this->lastLine);
        if ($length + 15 > $this->oneLineWord) {
            $length = $this->strlen($this->curPart);
            $this->curPart = $this->substr($this->curPart,0,$length - 9) . '　... <a href="'.$this->more['url'].'">'.$this->more['word'].'</a>';
        } else {
            $this->curPart .= '　... <a href="'.$this->more['url'].'">'.$this->more['word'].'</a>';
        }
    }

    //支持中文的字符串长度获取（每2个字符表示一个中文字符）
    function strlen($str)
    {
        $length = 0;
        for($i = 0,$len = strlen($str);$i < $len; ++ $i) {
            $w = substr($str,$i,1);
            if (ord($w) > 160) {
                $length += 2;
                $i += 2;
            } else
                $length ++;
        }
        return $length;
    }

    //截取字符串，长度不足则舍弃
    function substr($str,$start,$len)
    {
        $string = '';
        $length = strlen($str);
        $tmp_len = 0; $tmp_start = 0;
        for($i = 0;$i < $length; ++ $i) {
            if ($tmp_len >= $len) break;
            if ($i + 1 >= $start) {//die(','.$tmp_start);
                $w = substr($str,$tmp_start,1);
                if (ord($w) > 160) {
                    if ($tmp_len + 2 <= $len)
                        $string .= substr($str,$tmp_start,3);
                    $i += 2;
                    $tmp_len += 2;
                    $tmp_start += 3;
                } else {
                    $string .= substr($str,$tmp_start,1);
                    ++ $tmp_start;
                    ++ $tmp_len;
                }
            } else {
                $w = substr($str,$tmp_start,1);
                if (ord($w) > 160) {
                    $i += 1;
                    $tmp_start += 3;
                } else {
                    ++ $tmp_start;
                }
            }
        }
        return $string;
    }

}