wx.cloud.downloadfile可以将云存储的图片下载至本地相册吗？应该使用什么方法呢？ 我使用wx.saveImageToPhotosAlbum报错{errMsg: "saveImageToPhotosAlbum:fail invalid file type"}（已对相册进行授权） ‍ download: function() {     wx.getSetting({      success(res) {         if (!res.authSetting['scope.writePhotosAlbum']) {           wx.authorize({             scope: 'scope.writePhotosAlbum',             success() {               console.log('授权成功')             }           })         }       }     })    wx.cloud.downloadFile({       fileID: 'cloud://xpr-89f120.7870-xpr-89f120/contentCzV6', // 文件 ID     }).then(res => {       wx.saveImageToPhotosAlbum({         filePath: res.tempFilePath,         success: res => {           wx.showToast({             title: '下载成功',           })         },         fail: err => {           console.error(err)         }       })     }).catch(error => {       // handle error     }) download: function() {     console.log('aaa')     wx.getSetting({      success(res) {         if (!res.authSetting['scope.writePhotosAlbum']) {           wx.authorize({             scope: 'scope.writePhotosAlbum',             success() {               console.log('授权成功')             }           })         }       }     })    wx.cloud.downloadFile({       fileID: 'cloud://xpr-89f120.7870-xpr-89f120/contentCzV6', // 文件 ID     }).then(res => {       wx.saveImageToPhotosAlbum({         filePath: res.tempFilePath,         success: res => {           wx.showToast({             title: '下载成功',           })         },         fail: err => {           console.error(err)         }       })     }).catch(error => {       // handle error     })