WeChat applet obtains user openid through cloud function

openid is the unique identifier of the user's operation of the applet. The same user will have the same openid in different applets and different operations of the same applet. Therefore, openid is generally used to uniquely identify a user. The importance of openid in applets It is still very high. If you need to use data interaction, you need to use openid.

There are two or three ways to obtain openid. Here I will talk about the simplest way to obtain it by using cloud functions, just copy it directly.

First of all, I usually get it in onload to facilitate the display of data

To add the useropenid field in the data of js, it can be called any name, but the setdata must be modified accordingly

 wx.cloud.callFunction({
    name:'hellocloud',
    data:{
      message:'hellocloud',
    }
  }).then(res=>{
    console.log(res)//res就将appid和openid返回了
      //做一些后续操作，不用考虑代码的异步执行问题。
      that.setData({
        useropenid:res.result.openid
      })

Among them, that.setdata needs to be var this=that at the very beginning, which is not written in the code segment, because I intercepted it from the actual project, and there are many other things in the whole onload, just add var

The consol.log prints the data, and you can see whether the acquisition is successful in the background

Then, on the cloud function side, create a new node.js cloud function named hellocloud, and the js in it

as follows

const cloud = require('wx-server-sdk')

cloud.init()

// 云函数入口函数
exports.main = async (event, context) => {
  let{ APPID,OPENID}=cloud.getWXContext()
   return {
     APPID,
     OPENID
   }}

After uploading and deploying the cloud function, it can be used

After execution, see if it is displayed as follows

 This is what is printed out, which means the acquisition is successful.