Kiener's Blog

Silverlight 3 beta introduces a binary message encoder on the channel stack.

Binary encoding is implemented as a custom binding, there is no out-of-the-box binary binding.

<bindings>
  <customBinding>
	<binding name="binaryHttpBinding">
	   <binaryMessageEncoding />
         <httpTransport />
      </binding>
  </customBinding>
</bindings>
<endpoint address=""
          binding="customBinding"
          bindingConfiguration="binaryHttpBinding"
          contract="Service" />

If you would set the binding programmatically you have to configure your own CustomBinding instance.

This was the reason to implement the BasicHttpBinaryBinding class as you can find below.

/// <summary>
// Represents a basic http binding with binary encoding.
/// </summary>
public class BasicHttpBinaryBinding : BasicHttpBinding
{
    /// <summary>
    ///  Initializes a new instance of the BasicHttpBinaryBinding class.
    /// </summary>
    public BasicHttpBinaryBinding()
        : this(BasicHttpSecurityMode.None)
    {
    }

    /// <summary>
    /// Initializes a new instance of the BasicHttpBinaryBinding class.
    /// </summary>
    /// <param name="securityMode">
    /// The value of System.ServiceModel.BasicHttpSecurityMode that specifies 
    /// the type of security that is used with the SOAP message and for the client.
    /// </param>
    public BasicHttpBinaryBinding(BasicHttpSecurityMode securityMode)
        : this(securityMode, true)
    {
    }

    /// <summary>
    /// Initializes a new instance of the BasicHttpBinaryBinding class.
    /// </summary>
    /// <param name="securityMode">
    /// The value of System.ServiceModel.BasicHttpSecurityMode that specifies 
    /// the type of security that is used with the SOAP message and for the client.
    /// </param>
    /// <param name="binaryEncoding">
    /// Indicates whether the binary encoding is enabled or not
    /// </param>
    public BasicHttpBinaryBinding(BasicHttpSecurityMode securityMode, bool binaryEncoding)
        : base(securityMode)
    {
        this.BinaryEncoding = true;
        this.BinaryEncoding = binaryEncoding;
    }

    /// <summary>
    /// Gets or sets a value that indicates whether the binary encoding is enabled or not. Default is true.
    /// </summary>
    public bool BinaryEncoding { get; set; }

    /// <summary>
    /// Returns an ordered collection of binding elements contained in the current binding.
    /// </summary>
    public override BindingElementCollection CreateBindingElements()
    {
        BindingElementCollection elements = base.CreateBindingElements();

        if (this.BinaryEncoding)
        {
            // search the existing message encoding element (Text or MTOM) and replace it
            // note: the search must be done with the base type of text and mtom binding element, because this code is compiled against silverlight also 
            // and there is no mtom encoding available
            for (int i = elements.Count - 1; i >= 0; i--)
            {
                BindingElement element = elements[i];
                if (element.GetType().IsSubclassOf(typeof(MessageEncodingBindingElement)))
                {
                    elements.RemoveAt(i);
                    elements.Insert(i, new BinaryMessageEncodingBindingElement());
                    break;
                }
            }
        }

        return elements;
    }

}

The class is Silverlight compilable, therefore you can share it along the Silverlight and wcf-service project.

How to use: instead of the BasicHttpBinding you can use BasicHttpBinaryBinding as following to enable binary encoding.

BasicHttpBinding binding = new BasicHttpBinding();

BasicHttpBinding binding = new BasicHttpBinaryBinding();

Download the code here