Question

I have the following function to handle an uploaded image.

It works fine on the first attempt (after restarting IIS), but on the second attempt I always get

The process cannot access the file because it is being used by
another process

Now, I do understand that somehow the file is kept open by IIS, but why does it happen if I have

newFile.Flush();
newFile.Close();
newFile.Dispose();

Here is the full function:

private void SaveFile(HttpPostedFile file, string path)
{
    Int32 fileLength = file.ContentLength;
    string fileName = file.FileName;
    byte[] buffer = new byte[fileLength];
    file.InputStream.Read(buffer, 0, fileLength);

    FileStream newFile = new FileStream(path, FileMode.Create, FileAccess.Write);

    try
    {
        newFile.Write(buffer, 0, buffer.Length);
    }
    catch { }
    finally
    {
        newFile.Flush();
        newFile.Close();
        newFile.Dispose();
    }
}

UPDATE:
After a few checks, I am sure there is nothing else locking the file but w3wp.exe which is the IIS process.

Answer 1

Something else must be keeping the file open – or perhaps the second call is made (on a separate thread) before the first call has returned.

Incidentally, you would be better writing the code like this:

private void SaveFile(HttpPostedFile file, string path)
{
    Int32 fileLength = file.ContentLength;
    string fileName = file.FileName;
    byte[] buffer = new byte[fileLength];
    file.InputStream.Read(buffer, 0, fileLength);

    using (FileStream newFile = new FileStream(path, FileMode.Create, FileAccess.Write))
    {
        newFile.Write(buffer, 0, buffer.Length);
    }
}