是不是拒绝授权保存到本地了？

wx.getSetting({
  success: res => {
    let authSetting = res.authSetting
    if (!authSetting['scope.writePhotosAlbum']) {
       wx.showModal({
          title: '提示',
          content: '您未开启保存图片到相册的权限，请点击确定去开启权限！',
          success(res) {
            if (res.confirm) {
               wx.openSetting()
             }
          }
       })
     }
   }
})