// 获取微博登录地址
    oauth() {
      // 从后端获取 微博登录地址
      oauth_post().then((resp) => {
        console.log(resp)
        //{‘code‘: ‘0‘, ‘msg‘: ‘成功‘, ‘data‘: {‘url‘: url}}
        let url = resp.data.url;
        this.weibo_url = url;
      })

    },

mounted() { 
    this.oauth() 
}

<form 
    action="/login" 
    method="post" 
> 
    <div class="form-group widget-signin"> 
    <a :href="weibo_url"><i class="fa fa-weibo"></i></a> 
    </div> 
</form>