微信小程序下载一个视频到本地相册，显示下载进度，可取消下载

下载

  {
  {progress||0}}%
  正在下载成片，请稍等片刻…

//点击下载按钮

_onDownloadClick(){
    this.getPhotosAlbumAuth()
},

//获取相册权限
getPhotosAlbumAuth() {
  var that = this;
  wx.getSetting({
    success(res) {
      if (!res.authSetting['scope.writePhotosAlbum']) {
        wx.authorize({
          scope: 'scope.writePhotosAlbum',
          success:()=> { //这里是用户同意授权后的回调
            that.handleDownload();
          },
          fail:()=> { //这里是用户拒绝授权后的回调