www.lightcourse.com/extend/excel/Excel.php

<?php
namespace excel;
/**
 * 生成Excel文件类
 *
 */
class Excel
{
    /**
     * excel文档头(返回的行)
     *
     * 依照excel xml规范。
     * @access private
     * @var string
     */
    private $header = "<?xml version=\"1.0\" encoding=\"UTF-8\"?\>
	<Workbook xmlns=\"urn:schemas-microsoft-com:office:spreadsheet\"
	xmlns:x=\"urn:schemas-microsoft-com:office:excel\"
	xmlns:ss=\"urn:schemas-microsoft-com:office:spreadsheet\"
	xmlns:html=\"http://www.w3.org/TR/REC-html40\">";

    /**
     * excel页脚
     * 依照excel xml规范。
     *
     * @access private
     * @var string
     */
    private $footer = "</Workbook>";

    /**
     * 文档行(行数组中)
     *
     * @access private
     * @var array
     */
    private $lines = array();
    /**
     * 工作表(数组)
     *
     * @access private
     * @var array
     */
    private $worksheets = array();
    /**
     * 单元格样式
     * @access private
     * @var string
     */
    private $cellstyle = array();

    /**
     * 默认单元格数据格式
     * @access private
     * @var string
     */
    private $default_cellformat = "String";

    public function __construct()
    {
        //设置默认样式
        $this->cellstyle['Default'] = '<Style ss:ID="Default" ss:Name="Normal">
			   <Alignment ss:Vertical="Center"/>
			   <Borders/>
			   <Font ss:FontName="宋体" x:CharSet="134" ss:Size="11" ss:Color="#000000"/>
			   <Interior/>
			   <NumberFormat/>
			   <Protection/>
			  </Style>';
    }

    /**
     * 添加单行数据
     *
     * @access private
     * @param array 1维数组
     * @todo 行创建
     */
    private function addRow($array)
    {
        //初始化单元格
        $cells = "";
        //构建单元格
        foreach ($array as $k => $v) {
            $style_str = '';
            if (!empty($v['styleid'])) {
                $style_str = 'ss:StyleID="' . $v['styleid'] . '"';
            }
            $format_str = $this->default_cellformat;
            if (!empty($v['format'])) {
                $format_str = $v['format'];
            }
            $cells .= "<Cell {$style_str} ><Data ss:Type=\"{$format_str}\">{$v['data']}</Data></Cell>\n";
        }
        //构建行数据
        $this->lines[] = "<Row>\n" . $cells . "</Row>\n";
    }

    /**
     * 添加多行数据
     * @access public
     * @param array 2维数组
     * @todo 构造多行
     */
    public function addArray($array)
    {
        $this->lines = array();
        //构建行数据
        foreach ((array)$array as $k => $v) {
            $this->addRow($v);
        }
    }

    /**
     * 添加工作表
     * @access public
     * @param string $sheettitle 工作表名
     * @todo 构造工作表XML
     */
    public function addWorksheet($sheettitle)
    {
        //剔除特殊字符
        $sheettitle = preg_replace("/[\\\|:|\/|\?|\*|\[|\]]/", "", $sheettitle);
        //现在,将其减少到允许的长度
        //$sheettitle = substr ($sheettitle, 0, 50);
        $this->worksheets[] = "\n<Worksheet ss:Name=\"$sheettitle\">\n<Table ss:DefaultRowHeight=\"20\">\n" . "<Column ss:Index=\"1\" ss:AutoFitWidth=\"0\"/>\n" . implode("\n", $this->lines) . "</Table>\n</Worksheet>\n";
    }

    /**
     * 设置单元格样式
     *
     * @access public
     * @param array 样式数组例如： array('id'=>'s_title','Font'=>array('FontName'=>'宋体','Size'=>'12','Bold'=>'1'));
     * 当id为Default时，为表格的默认样式
     */
    public function setStyle($style_arr)
    {
        if (empty($style_arr)) {
            return false;
        }
        $id = $style_arr['id'];
        unset($style_arr['id']);
        $style_str = "<Style ss:ID=\"$id\">";
        foreach ($style_arr as $k => $v) {
            $tmp = '';
            foreach ((array)$v as $k_item => $v_item) {
                $tmp .= (" ss:$k_item=\"$v_item\"");
            }
            $style_str .= "<$k " . $tmp . '/>';
        }

        $this->cellstyle[$id] = $style_str . '</Style>';
    }

    /**
     * 设置默认单元格格式
     *
     * @access public
     * @param string
     */
    public function setDefaultFormat($format_str)
    {
        if (empty($style_arr)) {
            return false;
        }
        $this->default_cellformat = $format_str;
    }

    /**
     * 生成excel文件
     * 最后生成excel文件,并使用header()函数来将它交付给浏览器。
     * @access public
     * @param string $filename 文件名称
     */
    public function generateXML($filename)
    {
        $encoded_filename = urlencode($filename);
        $encoded_filename = str_replace("+", "%20", $encoded_filename);
        //头
        $ua = $_SERVER["HTTP_USER_AGENT"];
        header("Content-Type: application/vnd.ms-excel");
        if (preg_match("/MSIE/", $ua)) {
            header('Content-Disposition: attachment; filename="' . $encoded_filename . '.xls"');
        }
        else if (preg_match("/Firefox/", $ua)) {
            header('Content-Disposition: attachment; filename*="utf8\'\'' . $filename . '.xls"');
        }
        else {
            header('Content-Disposition: attachment; filename="' . $filename . '.xls"');
        }
        header('Cache-Control: max-age=0');
        echo stripslashes($this->header);
        //样式
        echo "\n<Styles>";
        foreach ((array)$this->cellstyle as $k => $v) {
            echo "\n" . $v;
        }
        echo "\n</Styles>";
        //工作表
        echo implode("\n", $this->worksheets);
        echo $this->footer;
    }

    /**
     * 转码函数
     *
     * @param mixed $content
     * @param string $from
     * @param string $to
     * @return mixed
     */
    public function charset($content, $from = 'gbk', $to = 'utf-8')
    {
        $from = strtoupper($from) == 'UTF8' ? 'utf-8' : $from;
        $to = strtoupper($to) == 'UTF8' ? 'utf-8' : $to;
        if (strtoupper($from) === strtoupper($to) || empty($content)) {
            //如果编码相同则不转换
            return $content;
        }
        if (function_exists('mb_convert_encoding')) {
            if (is_array($content)) {
                $content = var_export($content, true);
                $content = mb_convert_encoding($content, $to, $from);
                eval("\$content = $content;");
                return $content;
            }
            else {
                return mb_convert_encoding($content, $to, $from);
            }
        }
        elseif (function_exists('iconv')) {
            if (is_array($content)) {
                $content = var_export($content, true);
                $content = iconv($from, $to, $content);
                eval("\$content = $content;");
                return $content;
            }
            else {
                return iconv($from, $to, $content);
            }
        }
        else {
            return $content;
        }
    }
}

?>