前言

使用promise 隊(duì)列，保存多張圖片到手機(jī)相冊(cè)

問題:有些手機(jī)會(huì)出現(xiàn)只能保存五張圖片，報(bào)錯(cuò)信息:無法寫入

promise需要好好學(xué)習(xí)

核心代碼

// pages/saveImgs/index.js
import { writePhotosAlbum } from '../../utils/util'
Page({
 /**
 * 頁面的初始數(shù)據(jù)
 */
 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_201903011600298.jpg',
 'https://timgs.top1buyer.com/admin/special/special_img_20190301160031519.jpg',
 'https://timgs.top1buyer.com/admin/special/special_img_201903011600426.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_201903041601414.jpg'
 ],
 loading:false
 },

 /**
 * 生命周期函數(shù)--監(jiān)聽頁面加載
 */
 onLoad: function(options) {},
 // 下載圖片
 downloadImgs() {
 var _this = this
 // 獲取保存到相冊(cè)權(quán)限
 writePhotosAlbum(
 function success() {
 wx.showLoading({
 title: '加載中',
 mask: true
 })
 // 調(diào)用保存圖片promise隊(duì)列
 _this
 .queue(_this.data.list)
 .then(res => {
 wx.hideLoading()
 wx.showToast({
 title: '下載完成'
 })
 })
 .catch(err => {
 wx.hideLoading()
 console.log(err)
 })
 },
 function fail() {
 wx.showToast({
 title: '您拒絕了保存到相冊(cè)'
 })
 }
 )
 },
 // 隊(duì)列
 queue(urls) {
 let promise = Promise.resolve()
 urls.forEach((url, index) => {
 promise = promise.then(() => {
 return this.download(url)
 })
 })
 return promise
 },
 // 下載
 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)
 }
 })
 })
 }
})

項(xiàng)目案例

github地址

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

直接用微信小程序開發(fā)工具打開就可以看到案例了