獲取用戶openid

$appid = '';
  $appsecret = '';

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

            
            // 返回的url
            $redirect_uri=U('Api/getOpenid2homepage','','',true);
            $redirect_uri=urlencode($redirect_uri);
            $url='https://open.weixin.qq.com/connect/oauth2/authorize?appid='.$appid.'&redirect_uri='.$redirect_uri.'&response_type=code&scope=snsapi_userinfo&state=1#wechat_redirect';
            redirect($url);
        }else{
           
            $code=I('get.code');
            $url='https://api.weixin.qq.com/sns/oauth2/access_token?appid='.$appid.'&secret='.$appsecret.'&code='.$code.'&grant_type=authorization_code';
         
            $result=$this->httpGet($url);
            $result=json_decode($result,true);
           
            redirect(U('Api/homepage',array('openid' => $result['openid'])));
            
        }