System.IO.IsolatedStorage.IsolatedStorageFileEnumerator.GetIDStream C# (CSharp) Méthode

        private bool GetIDStream(String path, out Stream s)
        {
            StringBuilder sb = new StringBuilder();
            byte[]        b;

            sb.Append(m_rootDir);
            sb.Append(path);
            sb.Append(s_SepExternal);
            sb.Append(IsolatedStorageFile.s_IDFile);

            s = null;

            try {
                using(FileStream fs = new FileStream(sb.ToString(), FileMode.Open)) {
                    int length = (int) fs.Length;
                    b = new byte[length];
                    int offset = 0;
                    while(length > 0) {
                        int n = fs.Read(b, offset, length);
                        if (n == 0)
                            __Error.EndOfFile();
                        offset += n;
                        length -= n;
                    }
                }
                s = new MemoryStream(b);
            } catch {
                return false;
            }                    

            return true;
        }
    }