IsolatedStorageFile.GetLastAccessTime is crashing on wp7

Question

It sounds like "An error occurred while accessing IsolatedStorage". But there's no such exceptions is msdn: http://msdn.microsoft.com/en-us/library/system.io.isolatedstorage.isolatedstoragefile.getlastaccesstime(v=vs.110).aspx

I assume, it can be because i'm calling it inside of Task.Factory.StartNew(). Can it be a reason? It works on wp8 fine.

EDIT:

The problem was that I used GetLastAccessTime(cacheFileName).Millisecond; As it is said by the link by Agat, miliseconds are always 0 at the wp7. Or, actually, they are even not available, because exception is throwing while trying to access them. So just dont use Milliseconds, and that's it.

Is that a steady exception or occurs only from time to time? — Agat, Nov 09 '13 at 21:03
@Agat it appears always. On wp8 it returns real time, but on wp7 it is always 0. — Vitalii Vasylenko, Nov 09 '13 at 21:17
What's about any inner exceptions and what is the actual name of the top one? — Agat, Nov 09 '13 at 21:26
@Agat it is looking like http://clip2net.com/clip/m0/1384008861-clip-47kb.png The problem is that it always returns 0 for wp7, and some data for wp8. — Vitalii Vasylenko, Nov 09 '13 at 22:05
Still, try to lock the access for such operations, plus, I am not sure if I can "trust" the cacheFileName from the screenshot. he he — Agat, Nov 09 '13 at 22:10

Agat · Accepted Answer · 2013-11-09T23:35:00.697

3

If you just asking if it can be? I would rather answer that "yes, it can", and generally, because of the following:

To synchronize access to the local folder between different threads, we recommend using the Mutex class. A mutex grants exclusive access to a shared resource to only one thread. If one thread acquires a mutex, the second thread that wants to acquire that mutex is suspended until the first thread releases the mutex. For example, a mutex could be used to synchronize access to a folder between a Windows Phone app running in the foreground and a background agent.

But from other hands, if the exception occurs constantly, there might be a number of other reasons. Please have a look at this link, which can give you a clue about some specific things of GetLastAccessTime method work on Windows Phone 7.

edited Nov 09 '13 at 23:35

answered Nov 09 '13 at 22:02

Agat

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Yes, it appears constantly, on every call. – Vitalii Vasylenko Nov 09 '13 at 22:06
Thanks a tons! Indeed, miliseconds are always zeroed in wp7. Wondering, why it is not mentioned in documentation. – Vitalii Vasylenko Nov 09 '13 at 22:53
Hm... But you've mentioned something about error? Because if the method just returns 0, that might embarrasse another users which would start reading this question. – Agat Nov 09 '13 at 22:56
it is not just returning zero. Is also throws an exception if to try to get Milliseconds. – Vitalii Vasylenko Nov 09 '13 at 23:10
2

Aha. Well, that might be strange. However, anyway, I would still recommend you to use safe multithreading for such things. Slava Ukrajini! :) – Agat Nov 09 '13 at 23:15

IsolatedStorageFile.GetLastAccessTime is crashing on wp7

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