php生成小程序二维码

//生成二维码并下载
public function getQr($user_id){
    $accessToken = $this->getAccessToken();
    $url = "https://api.weixin.qq.com/wxa/getwxacodeunlimit?access_token=".$accessToken;
    $data['scene'] = $user_id;
    $data['width'] = 280;
    $res = $this->https_post($url,json_encode($data));
    $file = fopen('./public/qr/'.$name.'.jpg',"w");//打开文件准备写入
    fwrite($file,$res);//写入,$res为图片二进制内容
    fclose($file);//关闭
}
/**
    * 使用access_token接口，请求获得全局Access Token
    */
public function getAccessToken () {
    $wxAppConfigInfo = model("appConfig")->msg_info('id',1);
    $appid = $wxAppConfigInfo['appid'];
    $appsecret = $wxAppConfigInfo['appsecret'];
    $access = model('AccessToken');
    $access_list = $access->msg_info('id',1);
    $now_time = time();
    $time = $now_time - $access_list['time'];
    if($time > 7000){
        $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=$appid&secret=$appsecret";
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        $output = curl_exec($ch);
        curl_close($ch);
        $jsoninfo = json_decode($output, true);
        $access_token = $jsoninfo["access_token"];
        if($access_token){
            $access->msg_save(array('id'=>1),array('access_token'=>$access_token,'time'=>$now_time));
        }
    }else{
        $access_token = $access_list['access_token'];
    }
    return $access_token;
}
public function https_post($url,$data){
    $curl = curl_init();
    curl_setopt($curl, CURLOPT_URL, $url);
    curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, FALSE);
    curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, FALSE);
    curl_setopt($curl, CURLOPT_POST, 1);
    curl_setopt($curl, CURLOPT_POSTFIELDS, $data);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
    $result = curl_exec($curl);
    if (curl_errno($curl)) {
        return 'Errno'.curl_error($curl);
    }
    curl_close($curl);
    return $result;
}