Solved

File.SetLastWriteTime Not working as planned

Posted on 2014-01-28
9
512 Views
Last Modified: 2014-02-21
Hi All,
I am trying to set the File.SetLastWriteTime with that of a file that it was copied from.
It kinda works.  Problem is that when getting the new GetLastWriteTime it is one or two seconds greater than the date/time provided.

For instance if the Source file is 01/28/2014 1:18 PM, the Destination file, that is being altered, shows a value of 01/28/2014 1:20 PM. It's as if the SetLastWriteTime is working but taking a couple seconds, so that a new value is set.

example: (TDest$ and TSource$ are files, including paths)
File.SetLastWriteTime(TDest$, File.GetLastWriteTime(TSource$))

Any ideas?
0
Comment
Question by:Thunder724
  • 4
  • 3
  • 2
9 Comments
 
LVL 83

Expert Comment

by:CodeCruiser
ID: 39816487
That is actually 2 minutes not seconds. Is there any other code between the setting the time and closing the file?
0
 
LVL 4

Author Comment

by:Thunder724
ID: 39816535
Oh, sorry.... My fault in the example. it is actually seconds not minutes; I forgot to add the minute part.  No there is nothing between the code at all, that's why its driving me insane.
0
 
LVL 83

Expert Comment

by:CodeCruiser
ID: 39816542
Can you show your code?
0
 
LVL 4

Author Comment

by:Thunder724
ID: 39816551
sure, I put it in the original message.
But before that I am copying these files first.  
I even tried changing the SetLastWriteTime after the function that runs and contains the CopyFile function.

My.Computer.FileSystem.CopyFile(TSource$, TDest$, FileIO.UIOption.AllDialogs, FileIO.UICancelOption.ThrowException)

File.SetLastWriteTime(TDest$, File.GetLastWriteTime(TSource$))
0
3 Use Cases for Connected Systems

Our Dev teams are like yours. They’re continually cranking out code for new features/bugs fixes, testing, deploying, testing some more, responding to production monitoring events and more. It’s complex. So, we thought you’d like to see what’s working for us.

 
LVL 83

Expert Comment

by:CodeCruiser
ID: 39817332
If you do a

msgbox File.GetLastWriteTime(TSource$)

do you get the same datatime stamp as you see in explorer?
0
 
LVL 4

Author Comment

by:Thunder724
ID: 39818185
I can't explain it; but it looks to be working correctly now. I really didn't do anything either.
I will get back to you tomorrow to close this if everything is still testing out correctly.  
Thanks very much for you help.
0
 
LVL 27

Expert Comment

by:Ark
ID: 39820141
Which file system was on TDest$?
According to http://www.xxcopy.com/xxcopy15.htm
For the compatibility's sake, even WinNT/2K
  uses the same 2-second granularity for the "Last-modified" time for
  FAT-based file system (does not apply for NTFS files).
0
 
LVL 4

Author Comment

by:Thunder724
ID: 39825273
NTFS.
it seems to be a specific issue only when syncing to/from a usb stick.
0
 
LVL 27

Accepted Solution

by:
Ark earned 500 total points
ID: 39825782
There is another issue with NTFS - it does store time stamps with 100 ns granularity but it UPDATES values only after 1 hour
0

Featured Post

3 Use Cases for Connected Systems

Our Dev teams are like yours. They’re continually cranking out code for new features/bugs fixes, testing, deploying, testing some more, responding to production monitoring events and more. It’s complex. So, we thought you’d like to see what’s working for us.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Today I had a very interesting conundrum that had to get solved quickly. Needless to say, it wasn't resolved quickly because when we needed it we were very rushed, but as soon as the conference call was over and I took a step back I saw the correct …
This article shows how to deploy dynamic backgrounds to computers depending on the aspect ratio of display
This Micro Tutorial demonstrates using Microsoft Excel pivot tables, how to reverse engineer competitors' marketing strategies through backlinks.
Migrating to Microsoft Office 365 is becoming increasingly popular for organizations both large and small. If you have made the leap to Microsoft’s cloud platform, you know that you will need to create a corporate email signature for your Office 365…

920 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

12 Experts available now in Live!

Get 1:1 Help Now