获取openid [微信小程序]

  public function wxapi(){
        $data=$this->requestdata();
        if(!$data['code']) exit(json_encode(array('status'=>-1,'msg'=>'参数异常')));
        $paymentPlugin = M('Plugin')->where("code='weixin' and  type = 'payment' ")->find(); // 找到微信支付插件的配置
        $config_value = unserialize($paymentPlugin['config_value']); // 配置反序列化
        $appid = $config_value['appid']; // * APPID:绑定支付的APPID(必须配置,开户邮件中可查看)
        $mchid = $config_value['mchid']; // * MCHID:商户号(必须配置,开户邮件中可查看)
        $key = $config_value['key']; // KEY:商户支付密钥,参考开户邮件设置(必须配置,登录商户平台自行设置)
        $appsecret = $config_value['appsecret']; // 公众帐号secert(仅JSAPI支付的时候需要配置),
        $url = "https://api.weixin.qq.com/sns/jscode2session?appid=$appid&secret=$appsecret&grant_type=authorization_code&js_code=";
        $json=file_get_contents($url.$data["code"]);
        //$res = json_decode($res, true);
        $jsoarray = json_decode($json, true);

        exit(json_encode(array('status'=>1,'msg'=>'访问成功',"result"=>$jsoarray)));
    }

  code 微信小程序 wx.login获取到的