How can I convert Serialized stream to a string?

Question

I need to serialize and deserialize a list and write it on a JSON file to use later.

I successfully desirialize the file but failed to write after serialization. How can I do that?

Here is the code I have written.

StorageFile savedFile = await storageFolder.GetFileAsync("SavedData.json");
string text = await FileIO.ReadTextAsync(savedFile);
var serializer = new DataContractJsonSerializer(typeof(DataFormat));
var ms = new MemoryStream(Encoding.UTF8.GetBytes(text));
List<DataFormat> data = (List<DataFormat>)serializer.ReadObject(ms);
        if (data == null)
        {
            data = new List<DataFormat>();
        }
        data.Add(new DataFormat
        {
            firstName = fnbox.Text,
            lastName = lnbox.Text,
            country = cbox.Text
        });

MemoryStream stream = new MemoryStream();
DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(DataFormat));
ser.WriteObject(stream, data);

DataFormat Class -

[DataContract]
public class DataFormat : IEquatable<DataFormat>
{
    [DataMember]
    public string firstName{ get; set; }
    [DataMember]
    public string lastName { get; set; }
    [DataMember]
    public string country { get; set; }
    public bool Equals(DataFormat other)
    {
        if (other == null)
        {
            return false;
        }

        return (firstName.Equals(other.firstName));
    }

}

Additionally If there is any way to just add lines into an existing file without replacing all the text, please let me know.

Why not write directly to the file, as shown in the accepted answer to [Using DataContractJsonSerializer to create a Non XML Json file](https://stackoverflow.com/q/31130829)? — dbc, Feb 03 '19 at 13:36
What do you mean by saying "add lines"? Add a new data member or add a json object? And what's the error message you get? — Barry Wang, Feb 04 '19 at 07:51
I mean a new JSON object. And I didn't get any error cause I don't know how to write on a JSON file. That is the answer I need "How to write on a JSON file after serialization". Thanks. @BarryWang-MSFT — Mahmudul Hasan, Feb 04 '19 at 08:41

score 0 · Accepted Answer · answered Feb 05 '19 at 08:24

See if the following code is what you need. I'm not so sure whether you mean you don't understand how to write to stream.

  private async void Button_Click(object sender, RoutedEventArgs e)
    {
        Windows.Storage.StorageFolder storageFolder = Windows.Storage.ApplicationData.Current.LocalFolder;
        Windows.Storage.StorageFile sampleFile =await storageFolder.GetFileAsync("sample.json");
        DataFormat data = new DataFormat();
        data.firstName = "Barry";
        data.lastName = "Wang";
        data.country = "China";
        Stream mystream = await sampleFile.OpenStreamForWriteAsync();          
        DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(DataFormat));
        ser.WriteObject(mystream, data);
    }

Another short question, I need to convert data to a list after reading from an existing JSON file. How can do that? — Mahmudul Hasan, Feb 07 '19 at 07:07
[Jsonarray](https://learn.microsoft.com/en-us/uwp/api/windows.data.json.jsonarray) and Jsonobject can help you parse the string you get from your JSON file. You can then use a loop to read them to your list. — Barry Wang, Feb 14 '19 at 05:09

score -1 · Answer 2 · edited Feb 03 '19 at 15:28

-1

Here what you need, you can use LosFormatter class - see https://weblog.west-wind.com/posts/2006/Oct/13/LosFormatter-for-easy-Serialization

edited Feb 03 '19 at 15:28

Stephen Kennedy

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answered Feb 03 '19 at 15:25

Ashraf El-azoomy

1
1

How can I convert Serialized stream to a string?

2 Answers2