PHP教程
//获得回调函数
 public function actionCallback($code,$state){
    $model = new tp_tstz_proposal();
    $model1= new tp_tstz_staff();
    // 微信开放平台网站应用的appid和秘钥secret
    $appid = '';
    $secret = '';
    $curl = new curl\Curl();
    //获取access_token
    $wxresponse = $curl->get('https://api.weixin.qq.com/sns/oauth2/access_token?appid=' . $appid
      . '&secret=' . $secret . '&code=' . $code . '&grant_type=authorization_code');
    $wxresult = json_decode($wxresponse);
    if(isset($wxresult->errcode) && $wxresult->errcode > 0){
      //分享出去,重新认证
     return $this->render('login');
      // 向微信请求授权时出错,打印错误码
      // echo json_encode($wxresult);
      // exit;
    }
    $openid=$wxresult->openid;
    $result=$model1::find()->where(['openid'=>$openid])->one();
    //如果OPENID存在就去表单
    if(count($result)>0){
      $key=123456;
      return $this->render('view',['model'=>$model,'key'=>$key]);
    }else{
      return $this->render('tel',['model'=>$model1,'openid'=> $openid]);
    }
  }`

PHP教程
header('Location:https://open.weixin.qq.com/connect/oauth2/authorize?appid=wx8ba95fc51672e844&redirect_uri=http%3a%2f%2fjifen.wendu.cn%2fts%2fweb%2findex.PHP%3fr%3dproposal%2fcallback&response_type=code&scope=snsapi_base&state=123asd#wechat_redirect');

PHP教程
if(!isset($key)){
  header('Location:http://jifen.wendu.cn/ts/web/index.PHP?r=say/login');
}