正在分析Json Windows8

我在Windows8中尝试了多种解析json的方法，但我经常遇到这个错误。

"WinRT信息：WEB_E_INVALID_JSON_STRING"

到了这样一个地步，我使用了相同的json字符串，如果我从网络上读取它，它会起作用（或多或少），但如果我从本地文件读取它，则不会起作用。

以下是从网络上读取的代码：

 public async void ExamineJson()
    {
        string responseText = await GetjsonStream();
        ParseJson(responseText);
    }

public async Task<string> GetjsonStream()
    {
        HttpClient client = new HttpClient();
        string url = "http://rmarinho.facilit.us/app/d/rtp/config.json";
        HttpResponseMessage response = await client.GetAsync(url);
        return response.Content.ReadAsString();
    }

    private static void ParseJson(string responseText)
    {
        JsonObject root = new JsonObject(responseText);
        string epg = root.GetNamedString("epgurl");
        JsonArray themes = root["themes"].GetArray();
        for (int i = 0; i < themes.Count; i++)
        {
            JsonObject section = themes[i].GetObject();
        }
    }

所以这是有效的，但如果我使用相同的解析方法，并使用此代码从应用程序中的本地文件中获取文件，如果失败，则返回错误"WinRT信息：WEB_E_INVALID_JSON_STRING"。

FileSync.Read<string>(installedLocation, "config.json",
           (fileSize, reader) =>
               reader.ReadString(fileSize),
               responseText =>
               {
                   ParseJson(responseText);
               })
   public static class FileSync
{
    public static async void Read<TDocument>(StorageFolder folder, string fileName,
        Func<uint, DataReader, TDocument> reader, Action<TDocument> completion = null)
    {

        StorageFile file;
        IRandomAccessStream stream;
        IInputStream inputStream;
        DataReader dr;
        file = await folder.GetFileAsync(fileName);
        stream = await file.OpenAsync(FileAccessMode.Read);
        inputStream = stream.GetInputStreamAt(0);
        uint fileSize = (uint)stream.Size;
        dr = new DataReader(inputStream);
        await dr.LoadAsync(fileSize);
        Task<TDocument> task = new Task<TDocument>(() => reader(fileSize, dr));
        task.Start();
        TDocument doc = await task;
        if (completion != null)
        {
            completion(doc);
        }
    }
    public static async void Write<TDocument>(StorageFolder folder, string fileName,
CreationCollisionOption collisionOption, TDocument doc,
Action<DataWriter, TDocument> writer, Action<bool> complete = null)
    {
        StorageFile creator;
        IRandomAccessStream stream;
        IOutputStream outputStream;
        DataWriter dw;
        creator = await folder.CreateFileAsync(fileName, collisionOption);
        stream = await creator.OpenAsync(FileAccessMode.ReadWrite);
        outputStream = stream.GetOutputStreamAt(0);
        dw = new DataWriter(outputStream);
        Task task = new Task(() => writer(dw, doc));
        task.Start();
        await task;
        await dw.StoreAsync();
        bool success = await outputStream.FlushAsync();
        if (complete != null)
        {
            complete(success);
        }
    }
}

任何人都可以帮我弄清楚这是预览版的错误还是我缺少的东西？！

提前感谢

private readonly static string UTF8_BYTE_ORDER_MARK =
    Encoding.UTF8.GetString(Encoding.UTF8.GetPreamble(), 0, Encoding.UTF8.GetPreamble().Length);

        private string GetStringContentsOfFile(string path)
        {
            Uri filePath = new Uri(path);
            var jsonFileTask = StorageFile.GetFileFromApplicationUriAsync(filePath).AsTask();
            jsonFileTask.Wait();
            var jsonFile = jsonFileTask.Result;
            var getStringContentsTask = FileIO.ReadTextAsync(jsonFile, Windows.Storage.Streams.UnicodeEncoding.Utf8).AsTask();
            getStringContentsTask.Wait();
            var text = getStringContentsTask.Result;
            // FileIO.ReadTextAsync copies the UTF8 byte order mark into the result string. Strip the byte order mark
            text = text.Trim(UTF8_BYTE_ORDER_MARK.ToCharArray());
            return text;
        }