windows phone 7 isolated storage - operation not permitted

Question

So I've been working on a simple game and I wanted to implement a highscore system. Once the player loads up the main page for the first time a new text file is created ("hsc.txt") and some fake values are inserted which are later on split up by the program, however, currently my code throws a System.IO.IsolatedStorage.IsolatedStorageException and I can't seem to find the problem. I've looked up the error that I got from the message box which was "- operation not permitted" but all the solutions that were posted don't seem to work. I have tried closing the streams but it doesn't seem to work.

Any advice would be highly appreciated.

 private void hasHighscores()
      {
        String fileName = "hsc.txt";
        using  (var isoStorage = IsolatedStorageFile.GetUserStoreForApplication())
        {
            if (!isoStorage.FileExists(fileName))
            {
                isoStorage.CreateFile(fileName);

                       using (var isoStream = new IsolatedStorageFileStream(fileName,   FileMode.Append, FileAccess.Write, isoStorage))
                    {
                        using (var fileStream = new StreamWriter(isoStream))
                        {
                            fileStream.WriteLine("n1:666,n2:777,n3:888,h1:666,h2:777,h3:888");
                            fileStream.Close();
                        }
                        isoStream.Close();

                    }
            }
        }  
    }

So far I have: a) changed the FileMode b) changed the FileAccess and a few other "quickfixes" that I don't even remember.

Answer 1

The CreateFile method returns a stream to the created file, and keeps it open. Therefore, when you try to open a stream to that same file in the next line, it throws an exception because the file is already locked.

You can rewrite your code as follows:

 private void hasHighscores()
 {
        String fileName = "hsc.txt";
        using  (var isoStorage = IsolatedStorageFile.GetUserStoreForApplication())
        {
            if (!isoStorage.FileExists(fileName))
            {
                using (var isoStream = isoStorage.CreateFile(fileName))
                {
                    using (var fileStream = new StreamWriter(isoStream))
                    {
                        fileStream.WriteLine("n1:666,n2:777,n3:888,h1:666,h2:777,h3:888");
                    }  
                }
            }
        }  
    }

I've also removed the stream.Close() instructions. The close method is automatically called when you enclose the stream in a using statement.