ServiceHost responding with different XML

Question

IIS ASMX is responding with whole document:

<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
    <soap:Body>
        <eTimeServiceResponse xmlns="http://anet.eu/webservices">
            <eTimeServiceResult>ACA41A510200160000000000000000005BDFA1E076E2D3B3FD15F6DCF79F12B103F48C8955B3992FFE604FB79F703568</eTimeServiceResult>
        </eTimeServiceResponse>
    </soap:Body>
</soap:Envelope>

But WCF by ServiceHost is responding in OperationContract:

<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
    <s:Body>
        <eTimeServiceResponse xmlns="http://anet.eu/webservices">ACA41A510200160000000000000000005BDFA1E076E2D3B3FD15F6DCF79F12B103F48C8955B3992FFE604FB79F703568</eTimeServiceResponse>
    </s:Body>
</s:Envelope>

I am required to produce the same result in WCF host. As I read through multiple sources, I understand, that first is response with full XML document, but WCF is responding only with body of document. How can I configure exactly same response as for IIS ASMX? (Even that s alias instead soap could be problematic.) Very thanks.

_server = new ServiceHost(typeof(Service), new Uri(address));
ServiceThrottlingBehavior throttle = new ServiceThrottlingBehavior
{
    MaxConcurrentCalls = maxClient
};
_server.Description.Behaviors.Add(throttle);
_server.Open();

Answer 1

I've figured out the solution:

[AttributeUsage(AttributeTargets.Method)]
internal class EnvelopeFormatMessageAttribute : Attribute, IOperationBehavior
{
    internal class SoapEnvelopeMessageFormatter : IDispatchMessageFormatter
    {
        private readonly IDispatchMessageFormatter formatter;

        public SoapEnvelopeMessageFormatter(IDispatchMessageFormatter formatter)
        {
            this.formatter = formatter;
        }

        public void DeserializeRequest(Message message, object[] parameters) =>
            this.formatter.DeserializeRequest(message, parameters);

        public Message SerializeReply(MessageVersion messageVersion, object[] parameters, object result)
        {
            Message message = this.formatter.SerializeReply(messageVersion, parameters, result);
            return new SoapEnvelopeMessage(message);
        }
    }

    internal class SoapEnvelopeMessage : Message
    {
        private readonly Message message;

        public SoapEnvelopeMessage(Message message)
        {
            this.message = message;
        }
        public override MessageHeaders Headers => this.message.Headers;
        public override MessageProperties Properties => this.message.Properties;
        public override MessageVersion Version => this.message.Version;
        protected override void OnWriteStartBody(XmlDictionaryWriter writer) =>
            writer.WriteStartElement("Body", "http://schemas.xmlsoap.org/soap/envelope/"); // Request response
        protected override void OnWriteBodyContents(XmlDictionaryWriter writer) =>
            this.message.WriteBodyContents(writer);
        protected override void OnWriteStartEnvelope(XmlDictionaryWriter writer)
        {
            writer.WriteStartDocument(); // <?xml version="1.0" encoding="utf-8"?>
            writer.WriteStartElement("soap", "Envelope", "http://schemas.xmlsoap.org/soap/envelope/");
            writer.WriteAttributeString("xmlns", "xsi", null, "http://www.w3.org/2001/XMLSchema-instance");
            writer.WriteAttributeString("xmlns", "xsd", null, "http://www.w3.org/2001/XMLSchema");
        }
    }

    const string serializerBehaviorType = "datacontractserializeroperationbehavior";
    public void ApplyDispatchBehavior(OperationDescription operationDescription, DispatchOperation dispatchOperation)
    {
        IOperationBehavior serializerBehavior = operationDescription.OperationBehaviors.FirstOrDefault(ob =>
            serializerBehaviorType.Equals(ob.GetType().Name, StringComparison.InvariantCultureIgnoreCase));

        if (dispatchOperation.Formatter == null)
        {
            serializerBehavior.ApplyDispatchBehavior(operationDescription, dispatchOperation);
        }
        dispatchOperation.Formatter = new SoapEnvelopeMessageFormatter(dispatchOperation.Formatter);
    }

And then I can use it on any operation I want to be re-formatted.