Native implementation method of exporting and downloading excel with PHP

ob_start();
ob_get_contents
ob_end_clean
fopen
fwrite
fclose
iconv

header
iconv

进行缓存的设置
读取缓存
写入文件

<?php
class Excel 
{
    // ob函数缓存的开始
    public static function start ()
    {
        ob_start();
    }
    // 获取缓存内容
    public static function save ($path) 
    {
        $data = ob_get_contents();
        ob_end_clean();
        self::writeToExcel($path, $data);
    }
    //写到文件
    private static function writeToExcel ($fn, $data) 
    {
        $dir = self::setDir();
        $fp = fopen($dir . &#39;/&#39;. $fn, &#39;wb&#39;);
        fwrite($fp, $data);
        fclose($fp);
    }
    //excel默认是GKB，所有要转码
    public static function setChar ($value, $inchar = &#39;utf-8&#39;, $outchar =&#39;gbk&#39;)
    {
        return  iconv($inchar, $outchar, $value);//转化编码
    }
    //创建目录，linux系统一般要写到文件，目录需要w权限
    public static function setDir($dirName = &#39;excel&#39;)
    {
        if(!is_dir($dirName)) {
            mkdir($dirName);
        }
        return $dirName;
    }
}

<?php
    header(&#39;Content-Type: text/html; charset=GBK&#39;); //excel需要GBK编码，为了防止转码产生的乱码，需要设置成GBK
    require &#39;coon.php&#39;;
    require &#39;excel.class.php&#39;;
    $sql = &#39;select * from user&#39;;
    $res = $link->query($sql);
    //判断是否有发送get数据
    if(isset($_GET[&#39;id&#39;])){
        $name = empty($_GET[&#39;id&#39;]) ? &#39;a&#39; . rand(1000,9999) : $_GET[&#39;id&#39;] ;
        $filename = $name . &#39;.xls&#39;;
        //设置缓存的开始
        Excel::start();
    }
?>
<?php
    //页面输出一般是不需要转码的，excel输出才需要转码
    echo &#39;<table width=500 height=25 border=0 align=center cellpadding=0 cellspacing=0>&#39;;
    echo &#39;<thead><tr>&#39;;
    //设置thead输出
    echo &#39;<td style="border-bottom:1px solid black;padding:10px;text-align:center;">&#39; . Excel::setChar(&#39;编号&#39;) . &#39;</td>&#39;;
    echo &#39;<td style="border-bottom:1px solid black;padding:10px;text-align:center;">&#39; . Excel::setChar(&#39;用户名&#39;) . &#39;</td>&#39;;
    echo &#39;<td style="border-bottom:1px solid black;padding:10px;text-align:center;">&#39; . Excel::setChar(&#39;密码&#39;) . &#39;</td>&#39;;
    echo &#39;</thead></tr>&#39;;
?>
<?php
    echo &#39;<tbody>&#39;;
    //设置tbody输出
    while($re = $res->fetch(PDO::FETCH_ASSOC)){
        echo &#39;<tr>&#39;;
        echo &#39;<td style="border-bottom:1px solid black;padding:10px;text-align:center;">&#39; . Excel::setChar($re[&#39;id&#39;]) . &#39;</td>&#39;;
        echo &#39;<td style="border-bottom:1px solid black;padding:10px;text-align:center;">&#39; . Excel::setChar($re[&#39;user&#39;]) . &#39;</td>&#39;;
        echo &#39;<td style="border-bottom:1px solid black;padding:10px;text-align:center;">&#39; . Excel::setChar($re[&#39;pwd&#39;]) . &#39;</td>&#39;;
        echo &#39;</tr>&#39;;
    }
    echo &#39;</tbody></table>&#39;;
?>
<?php
if(isset($_GET[&#39;id&#39;])){
    //保存文件
    Excel::save($filename);
}
if(isset($_GET[&#39;id&#39;])){
    echo &#39;<a href="obexcel.php">&#39; .Excel::setChar(&#39;完成&#39;) .&#39;</a>&#39;;
}else{
    echo &#39;<a href="obexcel.php?id">&#39; . Excel::setChar(&#39;导出&#39;) .&#39;</a>&#39;;
    
}
?>

header("Content-type:application/vnd.ms-excel");//指定文件类型    
header("Content-Disposition:filename=a.xls" );  //指定下载文件名

query($sql);
?>

';
    echo '';
    //设置thead输出
    echo '' . Excel::setChar('编号') . '';
    echo '' . Excel::setChar('用户名') . '';
    echo '' . Excel::setChar('密码') . '';
    echo '';
?>

';
    //设置tbody输出
    while($re = $res->fetch(PDO::FETCH_ASSOC)){
        echo '';
        echo '' . Excel::setChar($re['id']) . '';
        echo '' . Excel::setChar($re['user']) . '';
        echo '' . Excel::setChar($re['pwd']) . '';
        echo '';
    }
    echo '';
?>