CODEWITHSUNDEEP
c#filelocking
Naveen Chakravarthy
Naveen Chakravarthy

Reputation: 839

C# how to lock the file

We are using an application that reads the file and inserts into database. For some reason, we set the creation time to a particular time. and when we create the file the application picks up the file before we even change the creation time. Is there anyway that we can lock the file until we change its creation time.

The error i am getting is at File.SetCreationTime as the file is being used by other process or the file is archived.

//Copy signal file
s = filePath + "s";
newS = targetFullPath2 + "s";
File.Copy(s, newS, true);
//
//new creation ts
dtFileCreation = File.GetCreationTime(s);
//retain creation time
File.SetCreationTime(newS, dtFileCreation);

Please advice.

Upvotes: 2

Views: 581

Answers (2)

Timwi
Timwi

Reputation: 66573

The common solution to this is to create the file (and set its timestamp) in a different directory or under a different name first, and then move or rename it when it’s ready so the other process can pick it up. The move/rename is an atomic operation on NTFS (unless of course you move files between separate partitions).

For example:

s = filePath + "s";
newS = targetFullPath2 + "s";
File.Copy(s, newS + "_", true);    // add the _ so the other process
                                   // doesn’t “see” the file yet

dtFileCreation = File.GetCreationTime(s);
File.SetCreationTime(newS + "_", dtFileCreation);

// We’re done with the file, now rename it to its intended final name
File.Move(newS + "_", newS);

Upvotes: 4

Zach Johnson
Zach Johnson

Reputation: 24212

That error indicates someone (it could be you or another program) is locking the file; therefore, I do not think locking the file will solve your problem. What kind of file is it? Is your code reading the file and forgetting to close the stream after it is done?

Upvotes: 1

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