HarmonyOS拍照saveUri的异常

import picker from '@ohos.multimedia.cameraPicker' 
import camera from '@ohos.multimedia.camera'; 
import common from '@ohos.app.ability.common'; 
import { BusinessError } from '@ohos.base'; 
import fileuri from '@ohos.file.fileuri'; 
import fs from '@ohos.file.fs'; 
let mContext = getContext(this) as common.Context; 
class CameraPosition { 
  cameraPosition : camera.CameraPosition 
  saveUri :string 
  constructor(cameraPosition : camera.CameraPosition,saveUri:string) { 
    this.cameraPosition = cameraPosition 
    this.saveUri = saveUri 
  } 
} 
let pathDir = getContext().filesDir; 
let filePath = pathDir + `/${new Date().getTime()}.jpg` 
fs.createRandomAccessFileSync(filePath, fs.OpenMode.CREATE); 
let uri = fileuri.getUriFromPath(filePath); 
async function demo() { 
  try { 
    let pickerProfile = new CameraPosition(camera.CameraPosition.CAMERA_POSITION_BACK,uri) 
    //前置摄像机传CAMERA_POSITION_FRONT，后置摄像机传CAMERA_POSITION_BACK，saveuri传想存到对应沙箱的uri 
    let pickerResult: picker.PickerResult = await picker.pick(mContext, [picker.PickerMediaType.PHOTO, picker.PickerMediaType.Video], pickerProfile); 
    console.log("the pick pickerResult is:" + JSON.stringify(pickerResult)); 
  } catch (error) { 
    let err = error as BusinessError; 
    console.error(`the pick call failed. error code: ${err.code}`); 
  } 
} 
@Entry 
@Component struct Photopage{ 
  build(){ 
    Column(){ 
      Button('拉起后置摄像头').onClick(()=>{ demo() }) 
    } 
  } 
}