选择相册怎么等待返回啊?

let  photoUris:Array<string> = ['']
try {
  let photoPick = new picker.PhotoViewPicker();
  let pickOptions = new picker.PhotoSelectOptions();
  pickOptions.maxSelectNumber = 1;
  pickOptions.MIMEType = picker.PhotoViewMIMETypes.IMAGE_TYPE;
  photoPick.select(pickOptions)
    .then((pickResult: picker.PhotoSelectResult) => {
      photoUris = pickResult.photoUris
    })
} catch (e) {
  photoUris = ['']
  console.error(e)
}
return photoUris