微信服务号获取openid方法

    public function tetst(){

      if(!isset($_GET['code'])){

              $APPID = $this->app_id;

              $ran = rand(1,100); //预防缓存

              $REDIRECT_URI = 'http://www.onedayoneclass.com/Home/Index/tetst?number='.$ran.''; //一定写上http://

              $scope='snsapi_userinfo';

              $url='https://open.weixin.qq.com/connect/oauth2/authorize?appid='.$APPID.'&redirect_uri='.urlencode($REDIRECT_URI).'&response_type=code&scope='.$scope.'&state=wx'.'#wechat_redirect';

              //加缓存 随机数

              header("Location:".$url);

          }else{

            $appid = $this->app_id;

            $secret = $this->app_secret;

             $code = $_GET["code"];

             $get_token_url = 'https://api.weixin.qq.com/sns/oauth2/access_token?appid='.$appid.'&secret='.$secret.'&code='.$code.'&grant_type=authorization_code';

             $ch = curl_init();

             curl_setopt($ch,CURLOPT_URL,$get_token_url);

             curl_setopt($ch,CURLOPT_HEADER,0);

             curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1 );

             curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 10);

             $res = curl_exec($ch);

             curl_close($ch);

             $json_obj = json_decode($res,true);

             //根据openid和access_token查询用户信息

             $access_token = $json_obj['access_token'];

             $openid = $json_obj['openid'];

             $get_user_info_url = 'https://api.weixin.qq.com/sns/userinfo?access_token='.$access_token.'&openid='.$openid.'&lang=zh_CN';

             $ch = curl_init();

             curl_setopt($ch,CURLOPT_URL,$get_user_info_url);

             curl_setopt($ch,CURLOPT_HEADER,0);

             curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1 );

             curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 10);

             $res = curl_exec($ch);

             curl_close($ch);

             //解析json

             $user_obj = json_decode($res,true);

             $_SESSION['user'] = $user_obj;

             print_r($user_obj);

         }

    }

结果：