我在将序列化字符串粘贴到.txt并将其反序列化以检索原始值时遇到了麻烦

我有一些麻烦弄清楚如何做到这一点，因为我以前从未序列化过。我能够将字符串转换为byte[]s，然后将它们序列化为新字符串，但无法将该序列化字符串保存为文本文件，重新导入并将其转换回原始值。记住，这是一个学习项目。这是我目前所做的

private string SerializeToString(string obj)
    {
        if (obj == null)
            return null;
        System.Runtime.Serialization.Formatters.Binary.BinaryFormatter bf = new System.Runtime.Serialization.Formatters.Binary.BinaryFormatter();
        MemoryStream ms = new MemoryStream();
        bf.Serialize(ms, obj);
        byte[] Array = ms.ToArray();
//This is where I create the txt file and write to it
            File.OpenWrite(Environment.GetFolderPath(Environment.SpecialFolder.Desktop)     + "''Text.txt")
            .Write(Array, 0, Array.Length);

        ms.Close();
        return Convert.ToBase64String(Array);
    }
        private void txtCheck_Click(object sender, RoutedEventArgs e)
    {
//I uploaded the file to drop box and can successfully download it but can not figure out
//how to get the original value out of it..
        string Url = "http://dl.dropbox.com/u/62170850/Text.txt";
        WebClient webClient = new WebClient();
        //webClient.DownloadFileCompleted += new AsyncCompletedEventHandler(Completed);
        //webClient.DownloadProgressChanged += new DownloadProgressChangedEventHandler(ProgressChanged);
        byte[] myDataBuffer = webClient.DownloadData(new Uri(Url));
        string s = Convert.ToBase64String(myDataBuffer);
    }