convert dictionary or list to byte[]

Question

Ok, i've seen many similar questions both on here and unity forums asking about converting from one format to another. I've got a (hopefully) simple question that i just can't find the answer for. I'm using the game-center plugin from Prime31 to handle a turn based multi-player game. Inside the plugin for Prime31 they ask you for a byte[] to send to the other players. (State data) So the question is, what would be a good way to convert a List to a byte array AND then convert them back from byte array?

for reference this is as complicated a class as i need, i might need to add more members later, but not any different types. ALSO the list of int's(cards in hand) could easily be 4 separate int if that makes converting the list of PokerPlayers to an byte[] any easier. Also at this list is not a set length but will always be 4-8.

public class PokerPlayer{   
    public string playerID;
    public string alias;
    public int wildCard;
    public List<int> cardsInHand;
    public int chips;   
}

I feel like the when i see the answer I'm going to smack myself for not seeing the answer sooner. Any pointers/ links to relevant materials would be sweet, i've searched google for a good 3 hours now with similar (SO similar) but not quite the same questions.

Cruiser

Question, do you only need the list put into an array, or the whole PokerPlayer object should be transferred to somewhere else? – Popedom

What i was doing was trying to convert a list of these PokerPlayers into a byte[] to send over the air thru gamecenter. – Cruiser

Answer 1

You may want to try serialization.

var binFormatter = new BinaryFormatter();
var mStream = new MemoryStream();
binFormatter.Serialize(mStream, myObjToSerialize);

//This gives you the byte array.
mStream.ToArray();

And then if you want to turn the byte array back into an object:

var mStream = new MemoryStream();
var binFormatter = new BinaryFormatter();

// Where 'objectBytes' is your byte array.
mStream.Write (objectBytes, 0, objectBytes.Length);
mStream.Position = 0;

var myObject = binFormatter.Deserialize(mStream) as YourObjectType;

Update:

Microsoft warns about using BinaryFormatter because it is "insecure and can't be made secure".

Please read aka.ms/binaryformatter for more details.

Preferred alternatives

.NET offers several in-box serializers that can handle untrusted data safely:

• XmlSerializer and DataContractSerializer to serialize object graphs into and from XML. Do not confuse DataContractSerializer with NetDataContractSerializer.
• BinaryReader and BinaryWriter for XML and JSON.
• The System.Text.Json APIs to serialize object graphs into JSON.

Safire

Awesome this was the way to go, i had to google getting the list back from the byte array, but it lead me to the right answer. So much thanks. – Cruiser

Hi its dont work for me, u can help ? IConvertible. in System.Convert.ChangeType – Nubile

Please check out aka.ms/binaryformatter. Microsoft's warning about using BinaryFormatter "The BinaryFormatter.Deserialize method is never safe when used with untrusted input.". – Estevez

Answer 2

BinaryFormatter is now a security risk. If I find a good way to do this without using it I'll be back

https://learn.microsoft.com/en-us/dotnet/core/compatibility/core-libraries/5.0/binaryformatter-serialization-obsolete

Edit: This is still the top result in Google so I'll show what I've done to move away from BinaryFormatter

You need Newtonsoft.Json

public static class ExtendedSerializerExtensions
{
    private static readonly JsonSerializerSettings SerializerSettings = new JsonSerializerSettings
    {
        TypeNameHandling = TypeNameHandling.Auto,
    };

    public static byte[] Serialize<T>(this T source)
    {
        var asString = JsonConvert.SerializeObject(source, SerializerSettings);
        return Encoding.Unicode.GetBytes(asString);
    }

    public static T Deserialize<T>(this byte[] source)
    {
        var asString = Encoding.Unicode.GetString(source);
        return JsonConvert.DeserializeObject<T>(asString);
    }
}

It's not very far to go from here if you need a stream rather than a byte array

Metalepsis

Answer 3

Converting data into byte stream (and back) is called serialization (and deserialization).

You can use the BinaryFormatter class to do so.

Dambro