前端通过如下链接获取微信code 然后将code返回给后端进行操作 https://open.weixin.qq.com/connect/oauth2/authorize?appid=wxbdf0aca1cea188fa&redirect_uri=http://gilson.m.alivatar.com/post.html&response_type=code&scope=snsapi_base&state=STATE#wechat_redirect
