实现步骤
2 第二步：通过code换取网页授权access_token
4 第四步：拉取用户信息(需scope为 snsapi_userinfo)
准备材料
一个服务号(已认证)，确保网页授权权限已开通
1、点击修改，跳转到公众号设置页，此处需要添加一个域名文件校验
2、通过authorize获取的code
调用https://open.weixin.qq.com/connect/oauth2/authorize
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=edge"/>
<meta name="viewport" content="width=device-width, initial-scale=1.0"/>
<title>Document</title>
</head>
<style>
</style>
<body>
<div id="container">
</div>
<script>
window.appId = `${appId}`
//注意：此处redirect_uri需要使用encodeURIComponent(该方法浏览器自带)转义
let local = "http://xxx"
// 跳转到授权页面
window.location.href =
"https://open.weixin.qq.com/connect/oauth2/authorize?appid=" +
window.appId +
"&redirect_uri=" +
encodeURIComponent(local) +
"&response_type=code&scope=snsapi_userinfo&state=1#wechat_redirect";
</script>
</body>
</html>
参数说明：
snsapi_base与snsapi_userinfo属于微信网页授权获取用户信息的两种作用域
snsapi_base只能获取access_token和openID
snsapi_userinfo可以获取更详细的用户资料，比如头像、昵称、性别等，该种形式会唤醒授权页面
3、调用https://api.weixin.qq.com/sns/oauth2/access_token，获取access_token
返回值如下
{"access_token":"accesstoken","refresh_token":"refreshtoken","openid":"openId","scope":"snsapi_userinfo","expires_in":7200}
常见错误码发生情况
{“errcode”:40029,“errmsg”:“invalid code, rid: 620e3db2-410d5515-117f31ac”}
这种问题一般都发生在code上，要检查code是不是有值并且是不是重复调用了
4、根据accessToken和openId查询用户信息，调用https://api.weixin.qq.com/sns/userinfo?access_token=accessToken&openid=openIdlang=zh_CN
返回值如下
{"country":"","province":"","city":"","openid":"openid","sex":0,"nickname":"sum墨","headimgurl":"https://thirdwx.qlogo.cn/mmopen/vi_32/KqPuMLU8JmRIlicUSvia4PR0vNKWKLFmfR6icibJ2Us7EyZXbZaKBd30qjGYJJSkmdHoib66wiaicQia61R34xC7Jr8EJg/132","language":"","privilege":[]}