WCF如何通过契约加编码方式调用

 public static T Create<T>(string endpointName)
        {
            if (string.IsNullOrEmpty(endpointName))
            {
                #region 默认配置，根据类名,赋值endpointName
                #endregion
                throw new ArgumentNullException("endpointName");
            }
            return (T)(new ServiceRealProxy<T>(endpointName).GetTransparentProxy());
        }

  public class ServiceRealProxy<T> : RealProxy
    {
        private readonly string _endpointName;

        public ServiceRealProxy(string endpointName)
            : base(typeof(T))
        {
            if (string.IsNullOrEmpty(endpointName))
            {
                throw new ArgumentNullException("endpointName");
            }
            _endpointName = endpointName;
        }

        public override IMessage Invoke(IMessage msg)
        {
            T channel = ChannelFactoryCreator.Create<T>(this._endpointName).CreateChannel();
            var methodCall = (IMethodCallMessage)msg;
            IMethodReturnMessage methodReturn = null;
            object[] copiedArgs = Array.CreateInstance(typeof(object), methodCall.Args.Length) as object[];
            methodCall.Args.CopyTo(copiedArgs, 0);
            try
            {
                object returnValue = methodCall.MethodBase.Invoke(channel, copiedArgs);
                methodReturn = new ReturnMessage(returnValue, copiedArgs, copiedArgs.Length, methodCall.LogicalCallContext, methodCall);
                var communicationObject = channel as ICommunicationObject;
                if (communicationObject != null) communicationObject.Close();
            }
            catch (Exception ex)
            {
                if (ex.InnerException is CommunicationException || ex.InnerException is TimeoutException)
                {
                    var communicationObject = channel as ICommunicationObject;
                    if (communicationObject != null) communicationObject.Abort();
                }

                methodReturn = ex.InnerException != null ? new ReturnMessage(ex.InnerException, methodCall) : new ReturnMessage(ex, methodCall);
            }

            return methodReturn;
        }
    }