1，h5端访问后端登录接口：

后端代码：

public function wxLogin(){
    //appId
    $refer_id = input('refer_id');
    $rank = input('rank');
    $appId = Db::name('wxsystem')->where('id',1)->value('appid');
    // $appId = 'wx5ea802d92c543852';
    // 回调的url
    $redirect_uri = urlencode('http://'.$_SERVER['HTTP_HOST'].'/api/Login/register/refer_id/'.$refer_id.'/rank/'.$rank);
    //跳转微信回调到redirect_uri获取code
    $url ="https://open.weixin.qq.com/connect/oauth2/authorize?appid=$appId&redirect_uri=$redirect_uri&response_type=code&scope=snsapi_userinfo&state=STATE#wechat_redirect";
    $this->redirect($url);
}

2，重定向到register方法：

public function register(){
    if(request()->post()){
        if(input('post.real_name') == '' || input('post.openid') == '' || input('post.password') == '' || input('post.mobile_phone') == ''){
            $this->error('请填写完整信息');
        }else{
            $user = Db::name('member')->where('openid',input('post.openid'))->find();
            if(!empty($user)){
                $this->error('该微信号已注册','api/login/login');
            }
            if(input('post.rank' == '')){
                $rank= Db::name('rank')->where('sort',4)->value('id');
            }else{
                $rank = input('post.rank');
            }
            $data = array(
                'real_name'=>input('post.real_name'),
                'username'=>'',
                'password'=>md5(md5(input('post.password'))),
                'mobile_phone'=>input('post.mobile_phone'),
                'weixin'=>input('post.weixin'),
                'register_time'=>date('Y-m-d H:i:s'),
                'openid'=>input('post.openid'),
                'refer_id'=>input('post.refer_id'),
                'is_xr'=>1,
                'shouquan_num'=>date("YHis"),
                'rank'=>$rank,
                'status'=>0,
                'avatar'=>input('avatar'),
            );
            $result = Db::name('member')->insertGetId($data);
          $openid = input('post.openid');
          $appid = Db::name('wxsystem')->where('id',1)->value('appid');
          $appscrect = Db::name('wxsystem')->where('id',1)->value('appscrect');
          $template_id = Db::name('template')->where('id',1)->value('zc_template_id');
          $this->SendWechatMessage($openid,$appid,$appscrect,$data1,$template_id);
          $template_id2 = Db::name('template')->where('id',1)->value('zc_template_id');
          $openid2 = Db::name('member')->where('member_id',input('post.refer_id'))->value('openid');
          $this->SendWechatMessage($openid2,$appid,$appscrect,$data1,$template_id2);
            if($result){
                $this->redirect('login/wxLogin1');
                // $this->wxLogin1();
                
            }else{
                $this->error('注册失败');
            }
        }
    }else{
        //获取code
        $code = $_GET["code"];
        // appId与appSecret 
        $appId = Db::name('wxsystem')->where('id',1)->value('appid');
      //  $appSecret = '1dcda2ca8542cf796c602a9fe81baf09';
        $appSecret = Db::name('wxsystem')->where('id',1)->value('appscrect');
        $url = "https://api.weixin.qq.com/sns/oauth2/access_token?appid=$appId&secret=$appSecret&code=$code&grant_type=authorization_code";
        $res = $this->sendRequest($url);
        $access_token = $res["access_token"];
        $openId  = $res['openid'];
        $getUserInfo = "https://api.weixin.qq.com/sns/userinfo?access_token=$access_token&openid=$openId&lang=zh_CN";
        //得到用户信息
        $user_info = $this->sendRequest($getUserInfo);

        $openid = $user_info['openid'];
        $refer_id = input('refer_id');
        $avatar = $user_info['headimgurl'];
        $this->assign('avatar',$avatar);
        $rank = input('rank');
        $this->assign('rank',$rank);
        $this->assign('openid',$openid);
        $this->assign('refer_id',$refer_id);
        return $this->fetch();
    }
}