public  function error($msg){

        header("Content-type: application/json");

        $o['time'] = "".time();

        $o['code'] = '1';

        $o['errorMsg'] = $msg;

        echo json_encode($o);

        die;

    }

 public function Attachment(){

        $d = array_merge($_POST,$_GET);

        if( empty($d['attachment']) ) $this->error("附件不能为空");

        //匹配出图片的格式

        if (!preg_match('/^(data:\s*image\/(\w+);base64,)/', $d['attachment'], $result))    $this->error('格式错误!');

        $type = $result[2];

        $attachment = $d['attachment'];

        $filename = date('His') . strtolower( base_convert(md5(microtime() . $_SERVER['DOCUMENT_ROOT']), 16, 10));

        $imgurl = "upload/";

        $imgurl = imgurl . $filename . "." . $type;

        file_put_contents($imgurl, base64_decode(str_replace($result[1], '', $attachment)))；

        return $imgurl;

    }