// pages/saveImgs/index.js
import { writePhotosAlbum } from '../../utils/util'
Page({
 /**
  * 页面的初始数据
  */
 data: {
  list: [
   'https://timgs.top1buyer.com/admin/special/special_img_20190301160008479.jpg',
   'https://timgs.top1buyer.com/admin/special/special_img_20190301160013201.jpg',
   'https://timgs.top1buyer.com/admin/special/special_img_20190301160015969.jpg',
   'https://timgs.top1buyer.com/admin/special/special_img_20190301160025498.jpg',
   'https://timgs.top1buyer.com/admin/special/special_img_20190301160031519.jpg',
   'https://timgs.top1buyer.com/admin/special/special_img_20190301160042689.jpg',
   'https://timgs.top1buyer.com/admin/special/special_img_20190301160108243.jpg',
   'https://timgs.top1buyer.com/admin/special/special_img_20190301160111756.jpg',
   'https://timgs.top1buyer.com/admin/special/special_img_20190304160141454.jpg'
  ],
  loading:false
 },

 /**
  * 生命周期函数--监听页面加载
  */
 onLoad: function(options) {},
 // 下载图片
 downloadImgs() {
  var _this = this
  // 获取保存到相册权限
  writePhotosAlbum(
   function success() {
    wx.showLoading({
     title: '加载中',
     mask: true
    })
    // 调用保存图片promise队列
    _this
     .queue(_this.data.list)
     .then(res => {
      wx.hideLoading()
      wx.showToast({
       title: '下载完成'
      })
     })
     .catch(err => {
      wx.hideLoading()
      console.log(err)
     })
   },
   function fail() {
    wx.showToast({
     title: '您拒绝了保存到相册'
    })
   }
  )
 },
 // 队列
 queue(urls) {
  let promise = Promise.resolve()
  urls.forEach((url, index) => {
   promise = promise.then(() => {
    return this.download(url)
   })
  })
  return promise
 },
 // 下载
 download(url) {
  return new Promise((resolve, reject) => {
   wx.downloadFile({
    url: url,
    success: function(res) {
     var temp = res.tempFilePath
     wx.saveImageToPhotosAlbum({
      filePath: temp,
      success: function(res) {
       resolve(res)
      },
      fail: function(err) {
       reject(res)
      }
     })
    },
    fail: function(err) {
     reject(err)
    }
   })
  })
 }
})

git clone https://github.com/sunnie1992/soul-weapp.git