From the MSDN documentation for the FileInfo.Name
property, I see that the data for the property is cached the first time it is called and will only be updated subsequently by using the Refresh
method.
I've the following questions which I can't find or aren't too clear in the documentation:
Is the data for all properties cached at the same time?
Is the
Refresh
method called on creation of theFileInfo
, or only when a property is called for the first time?If I've called one property, e.g. the
Name
property, and it's calledRefresh
, will calling a different property, e.g. theDirectoryName
property, for the first time cause it to callRefresh
again, or is it only called by the first property accessed in the entire class (see question #1)?Can I pre-cache all the properties by calling
Refresh
manually? (Assuming it's not pre-cached on construction of the object)Does calling
Refresh
manually cause properties which are pre-cached, e.g.CreationTime
, to be refreshed as well?
At a guess, yes. It seems like a bit of a self-defeating "optimisation" for
FileInfo
to fetch only the properties you've fetched before, especially when they can be (and probably are) all fetched in one API call.The fact that the documentation calls out
DirectoryInfo
methods which serve up already-cachedFileInfo
s suggests quite strongly (to me, anyway) that simply constructing aFileInfo
doesn't cache anything. It makes sense - if you construct aFileInfo
directly, it might refer to a file that doesn't exist yet (you plan to create it, for instance), whereas all the methods which return cachedFileInfo
s refer to files that exist at the time of the snapshot, under the assumption you're going to use at least some of them.No, by my answer to question 1. That's why the Refresh method is there.
I would imagine so (see answer 1).
Yes. See answer 3.
(MSDN)
Internally,
Refresh
calls the standard Win32API and thus fills all properties.Accessing any property that is specified to Refresh causes a full refresh, for instance: