1.創建雲函數

2.配置 config.json

{
  "permissions": {
    "openapi": [
      "wxacode.getUnlimited"
    ]
  }
}

3.雲函數代碼，會返回一個(gè)Buffer ，是(shì)小程序碼的(de)數據流。

const cloud = require('wx-server-sdk')
cloud.init()
exports.main = async (event, context) => {
  try {
    const result = await cloud.openapi.wxacode.getUnlimited({
        scene: event.scene
      })
      return result.buffer
  } catch (err) {
    return err
  }
}

4.在(zài)小程序調用雲函數并且賦值給Data

getCode(id) {
    var page = 'page/user/user'
    var scene = 'id='+that.data.group.qunId;
    wx.cloud.callFunction({
      name: "setCode",
      data: {
        scene
      },
      success(res) {
        console.log('獲取二維碼getCode-------------',scene, res.result)
        let fileManager = wx.getFileSystemManager(); //獲取文件管理器

        let filePath = wx.env.USER_DATA_PATH + '/inner.jpg'; //設置臨時(shí)路徑
        fileManager.writeFile({ //獲取到(dào)的(de)數據寫入臨時(shí)路徑
          filePath: filePath, //臨時(shí)路徑
          encoding: 'binary', //編碼方式，二進制
          data: res.result, //請求到(dào)的(de)數據
          success: function (res) {
            that.setData({
              code:filePath
            })
          }
        });
      },
      fail(err) {
        console.log('獲取二維碼getCode-------------', err)

      }
    })
  },