在 Windows Phone 7 上反序列化时出错

我正在尝试反序列化此字符串：""{'"Id'":1,'"Ent'":'"TUROS'",'"Data'":'"2010-09-09'",'"Ap'":'"004510875954'",'"Mat'":'"1129'"}""到对象，但我发现此错误：

There was an error deserializing the object of type Seguro. Data at the root level is invalid. Line 1, position 1.

我的代码：

private void sendPostCompleted(object sender, UploadStringCompletedEventArgs e)
    {
        // Handle result
        var status = e.Result;
        byte[] data = Encoding.UTF8.GetBytes(status);
        MemoryStream memStream = new MemoryStream(data);
        DataContractSerializer serializer = new DataContractSerializer(typeof(Seguro));
        Seguro car = (Seguro)serializer.ReadObject(memStream);

    }