如何从.NET ZipPackage中的文件获取文件属性（创建和修改）？

I'm using the ZipPackage-class in .NET to read and write zip-files. But how do I get basic file properties from files within a zip-package? I'm specifically looking for the date-times Created and Modified. I would prefer to not depend on a external lib of course, but it may be unavoidable...I'm using the ZipPackage-class in .NET to read