使用express获取微信小程序二维码小记

import express from 'express';
import axios from 'axios';
let qrcode = express.Router();
qrcode.post('/share',async (req,res)=>{
  try {
    let appid = 'wxc********b7a';
    let secret = '2bfa**************e8682';
    let url = `https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=${appid}&secret=${secret}`
    axios.get(url).then(res2=>{
      let scene = req.body._id;//开发者自己自定义的参数
      axios(
        {
          headers:{"Content-type":"application/json"},
          method: 'post',
          responseType: 'arraybuffer',
          url: 'https://api.weixin.qq.com/wxa/getwxacodeunlimit?access_token='+access_token+'',
          data:{
            scene:scene,
            page:'pages/infor/main',
            width: 280
          }
        }
      ).then(res3=>{
        //请求到的二维码buffer就在res3中
        //待完善区域
      })
    });
  } catch (error) {
    console.log(error)
  }
})
export default qrcode;

第二次axios请求，用option配置的方式，设置了responseType，避开了第二个坑。二维码的buffer数据就在res3中。

4.用buffer生成图片

只要buffer数据是完整的，就能正确生成二维码。

因为需要生成图片，所以需要引用fs模块和path模块。

import express from 'express';
import axios from 'axios';
import path from 'path';
import fs from 'fs';
let qrcode= express.Router();
qrcode.post('/share',async (req,res)=>{
  try {
    let appid = 'wxc********b7a';
    let secret = '2bfa**************e8682';
    let url = `https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=${appid}&secret=${secret}`;
    axios.get(url).then(res2=>{
      let access_token = res2.data.access_token;
      let scene = req.body._id;
      axios(
        {
          headers:{"Content-type":"application/json"},
          method: 'post',
          responseType: 'arraybuffer',
          url: 'https://api.weixin.qq.com/wxa/getwxacodeunlimit?access_token='+access_token+'',
          data:{
            scene:scene,
            page:'pages/infor/main',
            width: 280
          }
        }
      ).then(res3=>{
        let src = path.dirname(__dirname).replace(//g,'/')+`/public/photo/${req.body._id}.png`;
        fs.writeFile(src, res3.data, function(err) {
          if(err) {console.log(err);}
          res.json({msg:ok});
        });
      })
    });
  } catch (error) {
    console.log(error);
    res.json({error})
  }
})
export default qrcode;