获取PHAsset的本地文件路径

我有一张照片，我希望我的用户能够在Instagram上分享，我需要获取照片的本地文件目录。

I have a photo I want my user to be able to share on Instagram and I need to get the local file directory of the photo.

但是我正在抓取我的图像作为PHAsset（不是ALAsset所有其他答案似乎涵盖了这个主题）。

However I am fetching my images as a PHAsset (not the ALAsset all the other answers seem to cover on this subject).

查看PHAsset文档我没有看到'本地目录'变量。

Looking at the PHAsset documentation I don't see a 'local directory' variable.

你知道如何使用新的ios8 Photo框架从用户相机胶卷获取照片的路径吗？

Do you know how I can get the path to a photo from the users camera roll using the new ios8 Photo's framework?

这是我在用户照片卷中加载最后一张图片的代码

Here is my code for loading the last image in the users photo roll

public func loadLastPhotoIntoGalleryIcon()
{
    if(PHPhotoLibrary.authorizationStatus() != PHAuthorizationStatus.Authorized)
    {
        return
    }
    var fetchOptions:PHFetchOptions = PHFetchOptions()
    fetchOptions.sortDescriptors = [NSSortDescriptor(key: "creationDate", ascending: false)]
    var fetchResult:PHFetchResult = PHAsset.fetchAssetsWithMediaType(PHAssetMediaType.Image, options: fetchOptions)

    var lastAsset:PHAsset = fetchResult.firstObject as PHAsset

    var options:PHImageRequestOptions = PHImageRequestOptions()
    options.version = PHImageRequestOptionsVersion.Current
    PHImageManager.defaultManager().requestImageForAsset(lastAsset, targetSize: _view.getGalleryIconSize(), contentMode: PHImageContentMode.AspectFill, options: options)
    {
        (result, objects) -> Void in
        self._view.setGalleryIcon(result)
    }

}