HarmonyOS官方文档保存图片到用户相册，报系统错误

"requestPermissions": [ 
{'name':'ohos.permission.INTERNET'}, 
{ 
  'name':'ohos.permission.READ_IMAGEVIDEO', 
"reason": '$string:reason_string', 
"usedScene": { 
  "abilities": [ 
  "EntryAbility" 
  ], 
  "when": "inuse" 
} 
} 
, { 
  'name':'ohos.permission.WRITE_IMAGEVIDEO', 
  "reason": '$string:app_name', 
  "usedScene": { 
    "abilities": [ 
    "EntryAbility" 
    ], 
    "when": "inuse" 
  } 
}],

const context = getContext(this); 
let permissions: Array<Permissions> = [ 
  'ohos.permission.READ_IMAGEVIDEO', 
  'ohos.permission.WRITE_IMAGEVIDEO', 
]; 
function alertPremission() { 
  // requestPermissionsFromUser会判断权限的授权状态来决定是否唤起弹窗 
  atManager.requestPermissionsFromUser(context, permissions).then((data: PermissionRequestResult) => { 
    let grantStatus: Array<number> = data.authResults; 
    let length: number = grantStatus.length; 
    for (let i = 0; i < length; i++) { 
      if (grantStatus[i] != 0) { 
        // todo:用户拒绝授权，提示用户必须授权才能访问当前页面的功能，并引导用户到系统设置中打开相应的权限 
        return; 
      } 
    } 
  }).catch((err: BusinessError) => { 
    console.error( ` Failed to request permissions from user. Code is ${err.code}, message is ${err.message}`); 
  }) 
}

import dataSharePredicates from '@ohos.data.dataSharePredicates'; 
import photoAccessHelper from '@ohos.file.photoAccessHelper'; 
import abilityAccessCtrl, { PermissionRequestResult, Permissions } from '@ohos.abilityAccessCtrl'; 
import { BusinessError } from '@kit.BasicServicesKit'; 
import { promptAction } from '@kit.ArkUI'; 
const context = getContext(this); 
let permissions: Array<Permissions> = [ 
  'ohos.permission.READ_IMAGEVIDEO', 
  'ohos.permission.WRITE_IMAGEVIDEO', 
]; 
let phAccessHelper = photoAccessHelper.getPhotoAccessHelper(context); 
let atManager: abilityAccessCtrl.AtManager = abilityAccessCtrl.createAtManager(); 
async function example() { 
  let albumPredicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates(); 
  let albumName: photoAccessHelper.AlbumKeys = photoAccessHelper.AlbumKeys.ALBUM_NAME; 
  albumPredicates.equalTo(albumName, '1'); 
  let albumFetchOptions: photoAccessHelper.FetchOptions = { 
    fetchColumns: [], 
    predicates: albumPredicates 
  }; 
  let photoPredicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates(); 
  let photoFetchOptions: photoAccessHelper.FetchOptions = { 
    fetchColumns: [], 
    predicates: photoPredicates 
  }; 
  try { 
    let albumFetchResult: photoAccessHelper.FetchResult<photoAccessHelper.Album> = await phAccessHelper.getAlbums(photoAccessHelper.AlbumType.USER, photoAccessHelper.AlbumSubtype.USER_GENERIC, albumFetchOptions); 
    let album: photoAccessHelper.Album = await albumFetchResult.getFirstObject(); 
    console.info('getAlbums successfully, albumName: ' + album.albumName); 
    let photoFetchResult: photoAccessHelper.FetchResult<photoAccessHelper.PhotoAsset> = await phAccessHelper.getAssets(photoFetchOptions); 
    let photoAsset: photoAccessHelper.PhotoAsset = await photoFetchResult.getFirstObject(); 
    console.info('getAssets successfully, albumName: ' + photoAsset.displayName); 
    let albumChangeRequest: photoAccessHelper.MediaAlbumChangeRequest = new photoAccessHelper.MediaAlbumChangeRequest(album); 
    albumChangeRequest.addAssets([photoAsset]); 
    await phAccessHelper.applyChanges(albumChangeRequest); 
    console.info('succeed to add ' + photoAsset.displayName + ' to ' + album.albumName); 
    albumFetchResult.close(); 
    photoFetchResult.close(); 
    promptAction.showToast({message:'保存成功'}) 
  } catch (err) { 
    promptAction.showToast({message:'保存失败'}) 
    console.error('addAssets failed with err: ' + err); 
  } 
} 
function alertPremission() { 
  // requestPermissionsFromUser会判断权限的授权状态来决定是否唤起弹窗 
  atManager.requestPermissionsFromUser(context, permissions).then((data: PermissionRequestResult) => { 
    let grantStatus: Array<number> = data.authResults; 
    let length: number = grantStatus.length; 
    for (let i = 0; i < length; i++) { 
      if (grantStatus[i] != 0) { 
        // todo:用户拒绝授权，提示用户必须授权才能访问当前页面的功能，并引导用户到系统设置中打开相应的权限 
        return; 
      } 
    } 
  }).catch((err: BusinessError) => { 
    console.error( ` Failed to request permissions from user. Code is ${err.code}, message is ${err.message}`); 
  }) 
} 
@Entry 
@Component 
struct Index { 
  aboutToAppear(): void { 
    alertPremission() 
  } 
  build() { 
    Row() { 
      Column() { 
        Text('Hello World') 
          .fontSize(50) 
          .fontWeight(FontWeight.Bold) 
          .backgroundColor(Color.Yellow) 
          .onClick(()=>{ 
            example() 
          }) 
      }.width('100%') 
    }.height('100%') 
  } 
}