HarmonyOS 拍照相关问题

请参考下面demo来修改：

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 takePhoto() {
  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], 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}`);
  }
}