如何获得iPhone图库中的所有图片，而不必要求用户在Xamarin中选择它们？

using Foundation;
using Photos;

public void GetPhotosFromGallery()
{
    PHPhotoLibrary.RequestAuthorization(status =>
    {
        if (status == PHAuthorizationStatus.Authorized)
        {
            PHFetchOptions fetchOptions = new PHFetchOptions();
            PHFetchResult fetchResult = PHAsset.FetchAssets(fetchOptions);

            foreach (PHAsset asset in fetchResult)
            {
                if (asset.MediaType == PHAssetMediaType.Image)
                {
                    PHImageManager.DefaultManager.RequestImageData(asset, null, (data, dataUti, orientation, info) =>
                    {
                        // 处理图像数据
                        // data 包含图像的原始数据
                        // dataUti 提供图像的UTI(Unified Type Identifier)
                        // orientation 图像方向
                        // info 其他信息
                    });
                }
            }
        }
    });
}

<key>NSPhotoLibraryUsageDescription</key>
<string>App需要访问您的相册以获取图片。</string>