This is an example how to "wrap" binary objects using JavaScript and pass them to the XSocketsController.

default.html

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using XSockets.Core.Common.Socket.Event.Arguments;
using XSockets.Core.XSocket;
using XSockets.Core.XSocket.Helpers;

namespace XSockets.Example.BinaryWrapper
{

    public class BinaryMessageWrapper
    {
        public Guid MessageId { get; set; }
        public int ByteLength { get { return this.Buffer.Count(); } }
        public IList<byte> Buffer { get; set; }

        public BinaryMessageWrapper(byte[] arrayBuffer)
        {
            this.MessageId = Guid.Parse((Encoding.UTF8.GetString(arrayBuffer, 0, 36)));
            this.Buffer = arrayBuffer.Skip(36).Take(arrayBuffer.Length - 36).ToList();
        }
    }
    public class MyBinaryController : XSocketController
    {
        private static readonly List<BinaryMessageWrapper> MyBinaries;
        static MyBinaryController()
        {
            MyBinaries = new List<BinaryMessageWrapper>();

        }


        public override void OnMessage(Core.Common.Socket.Event.Interface.IBinaryArgs binaryArgs)
        {
            var myBinary = new BinaryMessageWrapper(binaryArgs.data.ToArray());
            // Just tell everyone that a blob is recieved
            this.SendToAll(new { messageId = myBinary.MessageId, bytesReceived = myBinary.ByteLength }, "binaryRecieved");

            // Store this in a static list , hmm , yes, its prolly better to reflect tge stuff into some other storage..

            MyBinaries.Add(myBinary);


            //base.OnMessage(binaryArgs);  We are not sending the blob now...


        }

        /// <summary>
        /// When a user ask's (triggers) for a message, pass back that buffer..
        /// </summary>
        /// <param name="messageId"></param>
        public void GetBinary(Guid messageId)
        {
            var myBinary = MyBinaries.FirstOrDefault(b => b.MessageId.Equals(messageId));
            if (myBinary == null) return;
            this.Send(new BinaryArgs(myBinary.Buffer));
        }

        /// <summary>
        /// Okey, lets remove the binary....
        /// </summary>
        /// <param name="messageId"></param>
        public void RemoveBinary(Guid messageId)
        {
            var removeThis = MyBinaries.FirstOrDefault(b => b.MessageId.Equals(messageId));
            MyBinaries.Remove(removeThis);
            this.Send(new { messageId = messageId }, "binaryRemoved");
        }

    }
}

MyBinaryController.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using XSockets.Core.Common.Socket.Event.Arguments;
using XSockets.Core.XSocket;
using XSockets.Core.XSocket.Helpers;

namespace XSockets.Example.BinaryWrapper
{

    public class BinaryMessageWrapper
    {
        public Guid MessageId { get; set; }
        public int ByteLength { get { return this.Buffer.Count(); } }
        public IList<byte> Buffer { get; set; }

        public BinaryMessageWrapper(byte[] arrayBuffer)
        {
            this.MessageId = Guid.Parse((Encoding.UTF8.GetString(arrayBuffer, 0, 36)));
            this.Buffer = arrayBuffer.Skip(36).Take(arrayBuffer.Length - 36).ToList();
        }
    }
    public class MyBinaryController : XSocketController
    {
        private static readonly List<BinaryMessageWrapper> MyBinaries;
        static MyBinaryController()
        {
            MyBinaries = new List<BinaryMessageWrapper>();

        }


        public override void OnMessage(Core.Common.Socket.Event.Interface.IBinaryArgs binaryArgs)
        {
            var myBinary = new BinaryMessageWrapper(binaryArgs.data.ToArray());
            // Just tell everyone that a blob is recieved
            this.SendToAll(new { messageId = myBinary.MessageId, bytesReceived = myBinary.ByteLength }, "binaryRecieved");

            // Store this in a static list , hmm , yes, its prolly better to reflect tge stuff into some other storage..

            MyBinaries.Add(myBinary);


            //base.OnMessage(binaryArgs);  We are not sending the blob now...


        }

        /// <summary>
        /// When a user ask's (triggers) for a message, pass back that buffer..
        /// </summary>
        /// <param name="messageId"></param>
        public void GetBinary(Guid messageId)
        {
            var myBinary = MyBinaries.FirstOrDefault(b => b.MessageId.Equals(messageId));
            if (myBinary == null) return;
            this.Send(new BinaryArgs(myBinary.Buffer));
        }

        /// <summary>
        /// Okey, lets remove the binary....
        /// </summary>
        /// <param name="messageId"></param>
        public void RemoveBinary(Guid messageId)
        {
            var removeThis = MyBinaries.FirstOrDefault(b => b.MessageId.Equals(messageId));
            MyBinaries.Remove(removeThis);
            this.Send(new { messageId = messageId }, "binaryRemoved");
        }

    }
}