详解微信小程序-获取用户session_key,openid,unionid - 后端为nodejs

更新时间：2020-08-24 02:06:01 作者：startmvc

微信小程序-获取用户session_key,openid,unionid-后端为nodejs8.0+步骤：1、通过wx.login接口获取code既

微信小程序-获取用户session_key,openid,unionid - 后端为nodejs8.0+

步骤：

1、通过wx.login接口获取code既jscode，传递到后端；

2、后端请求

https://api.weixin.qq.com/sns/jscode2session?appid=APPID&secret=SECRET&js_code=JSCODE&grant_type=authorization_code

地址，就能获取到openid和unionid。

小程序接口promise化和封装

1、utils文件夹下创建wechat.js文件


/**
 * Promise化小程序接口
 */
class Wechat {
 /**
 * 登陆
 * @return {Promise} 
 */
 static login() {
 return new Promise((resolve, reject) => wx.login({ success: resolve, fail: reject }));
 };
 
 /**
 * 获取用户信息
 * @return {Promise} 
 */
 static getUserInfo() {
 return new Promise((resolve, reject) => wx.getUserInfo({ success: resolve, fail: reject }));
 };
 
 /**
 * 发起网络请求
 * @param {string} url 
 * @param {object} params 
 * @return {Promise} 
 */
 static request(url, params, method = "GET", type = "json") {
 console.log("向后端传递的参数", params);
 return new Promise((resolve, reject) => {
 let opts = {
 url: url,
 data: Object.assign({}, params),
 method: method,
 header: { 'Content-Type': type },
 success: resolve,
 fail: reject
 }
 console.log("请求的URL", opts.url);
 wx.request(opts);
 });
 };
 
 /**
 * 获取微信数据,传递给后端
 */
 static getCryptoData() {
 let code = "";
 return this.login()
 .then(data => {
 code = data.code;
 console.log("login接口获取的code:", code);
 return this.getUserInfo();
 })
 .then(data => {
 console.log("getUserInfo接口", data);
 let obj = {
 js_code: code,
 };
 return Promise.resolve(obj);
 })
 .catch(e => {
 console.log(e);
 return Promise.reject(e);
 })
 };
 
 /**
 * 从后端获取openid
 * @param {object} params 
 */
 static getMyOpenid(params) {
 let url = 'https://xx.xxxxxx.cn/api/openid';
 return this.request(url, params, "POST", "application/x-www-form-urlencoded");
 };
}
module.exports = Wechat;

2、修改小程序的app.js文件


let wechat = require('./utils/wechat.js');
App({
 onLaunch() {
 this.getUserInfo();
 },
 getUserInfo() {
 wechat.getCryptoData()
 .then(d => {
 return wechat.getMyOpenid(d);
 })
 .then(d => {
 console.log("从后端获取的openid", d.data);
 })
 .catch(e => {
 console.log(e);
 })
 }
})

后端nodejs，是用的express命令行生成的项目框架，

1、创建common文件夹，创建utils文件，使用request模块请求接口，promise化request


const request = require("request");
class Ut {
 
    /**
     * promise化request
     * @param {object} opts 
     * @return {Promise<[]>}
     */
    static promiseReq(opts = {}) {
	return new Promise((resolve, reject) => {
	    request(opts, (e, r, d) => {
 if (e) {
     return reject(e);
 }
	        if (r.statusCode != 200) {
     return reject(`back statusCode：${r.statusCode}`);
 }
 return resolve(d);
	    });
	})
    };
 
};
 
module.exports = Ut;

2、新增路由，appId、secret在小程序的后台获取


router.post("/openid", async (req, res) => {
 const Ut = require("../common/utils");
 try {
 console.log(req.body);
 let appId = "wx70xxxxxxbed01b";
 let secret = "5ec6exxxxxx49bf161a79dd4";
 let { js_code } = req.body;
 let opts = {
 url: `https://api.weixin.qq.com/sns/jscode2session?appid=${appId}&secret=${secret}&js_code=${js_code}&grant_type=authorization_code`
 }
 let r1 = await Ut.promiseReq(opts);
 r1 = JSON.parse(r1);
 console.log(r1);
 res.json(r1);
 }
 catch (e) {
 console.log(e);
 res.json('');
 }
})

结果：