Why is the file still locked? and why does fully restarting Visual Studio reset the File? when checking file-Properties it says [...] I don't know why the file is still locked: probably because your code fails before the stream is closed/disposed.
About "why fully restarting Visual Studio [...]": because you may be using IIS Express or ASP.NET Dev Server whose are closed when you close the IDE, so locks on files are released since the process holding the locks is no longer running.
And about "why is the file still locked?[...]" it could be because the file stream isn't closed because sometimes the thread may not end successfully and the locks aren't released.
As other answer said, check how using
block may avoid that IDisposable
objects wouldn't be disposed:
// FileShare.ReadWrite will allow other processes
// to read and write the target file even if other processes
// are working with the same file
using var mailinglist_FileStream = new FileStream(@"\foobarFile.txt", FileMode.Open, FileShare.ReadWrite);
using var mailinglist_Reader = new PeekingStreamReader(mailinglist_FileStream);
// Do your stuff. Using blocks will call Dispose() for
// you even if something goes wrong, as it's equal to a try/finally!
I am only reading this File. can i do something similiar to adLockOptimistic, so that multiple processes can access the File?
Yes, take a look at File.Open
method and FileShare
enumeration: