ios - In PhotoKit, modifying PHAsset leaves original around. How? Overridable?

Question

It seems like modifications to a particular PHAsset photo keep a version of the original around somehow, in order to be able to do this:

1. Is this documented (from a programming standpoint) somewhere?
2. Can the original asset ever be overwritten?

Answer 1

PHImageManager: requestImageForAsset: 参考文档给出了这里发生的一些细节。

似乎您永远无法覆盖原始图像数据（资产在技术上只是元数据），因为您可以为PHImageRequestOptions包含version. PHImageRequestOptionsVersionOriginal从PHImageRequestOptions 文档中：

请求图像资产的原始、最高保真版本。

无论进行任何编辑，生成的图像都是最初捕获或导入的资产版本。