> <muralidhar***@hotmail.com> wrote in message
> news:1154775802.522701.32070@p79g2000cwp.googlegroups.com...
> > Hi All,
> >
> >   Can anyone explain the differences between FileShare.None and
> > FileShare.ReadWrite  in filestreams using C#.NET windows application?
> >
>
> FileShare.None declares that you are unwilling to share access to the file
> with anyone else.  You will open the file exclusively and if any other
> process attempts to open the file, an error will be raised.
> FileShare.ReadWrite declares that you are willing to share both read an
> write access to the file with other users.
>
> David

> Thanks Mr.David.
>
> I have a C# windows legacy framework. In my framework, Iam able to
> access a file using FileShare.None from two different applications.
> But the same fails when I try to access from same application multiple
> times.
>  The code that I had written is:
>
>               FileStream stream = new FileStream(_MessageFile,
> FileMode.Open,             FileAccess.ReadWrite, FileShare.None);
> int byteCount = (int)stream.Length;
> if (byteCount == 0)
> {
>           stream.Close();
>          return;
> }

> GVN wrote:
> > Thanks Mr.David.
> >
> > I have a C# windows legacy framework. In my framework, Iam able to
> > access a file using FileShare.None from two different applications.
> > But the same fails when I try to access from same application multiple
> > times.
> >  The code that I had written is:
> >
> >               FileStream stream = new FileStream(_MessageFile,
> > FileMode.Open,             FileAccess.ReadWrite, FileShare.None);
> > int byteCount = (int)stream.Length;
> > if (byteCount == 0)
> > {
> >           stream.Close();
> >          return;
> > }
>
> What happens is byteCount is not 0?  You still have the file open, unless
> there's code that you didn't show that closes it.
>
> >
> > When my application executes, I get the following error message:
> >
> >     "System.IO.IOExceptionn in MSCORLIB.dll. The file test.ipc is
> > already in use"
> > Can you please explain.
>
> That error indicates that you haven't closed the file after opening it the
> first time.  Make sure that you call FileStream.Close (or Dispose) when
> you're done with the file.  FileShare.None means that you can't even share
> access to the file with yourself, so you can have only one open handle to
> the file at a time.
>
> -cd

> Thanks Mr. Daniel.
>
> I have added some more code to my application.
>
> The following is the new code:
>
>  if (byteCount == 0)
> {
>                stream.Close();
>                return;
> }
> byte[] bytes = new byte[byteCount];
> stream.Lock(0, byteCount);
> stream.Read(bytes, 0, byteCount);
> stream.SetLength(0);
> stream.Unlock(0, byteCount);
> stream.Close();
>
> Eventhough Iam getting the same exception. Can you please explain me
> what is the cause?
>
> Thanks,
>
> GVN.
>
> Carl Daniel [VC++ MVP] wrote:
>
> > GVN wrote:
> > > Thanks Mr.David.
> > >
> > > I have a C# windows legacy framework. In my framework, Iam able to
> > > access a file using FileShare.None from two different applications.
> > > But the same fails when I try to access from same application multiple
> > > times.
> > >  The code that I had written is:
> > >
> > >               FileStream stream = new FileStream(_MessageFile,
> > > FileMode.Open,             FileAccess.ReadWrite, FileShare.None);
> > > int byteCount = (int)stream.Length;
> > > if (byteCount == 0)
> > > {
> > >           stream.Close();
> > >          return;
> > > }
> >
> > What happens is byteCount is not 0?  You still have the file open, unless
> > there's code that you didn't show that closes it.
> >
> > >
> > > When my application executes, I get the following error message:
> > >
> > >     "System.IO.IOExceptionn in MSCORLIB.dll. The file test.ipc is
> > > already in use"
> > > Can you please explain.
> >
> > That error indicates that you haven't closed the file after opening it the
> > first time.  Make sure that you call FileStream.Close (or Dispose) when
> > you're done with the file.  FileShare.None means that you can't even share
> > access to the file with yourself, so you can have only one open handle to
> > the file at a time.
> >
> > -cd