WCF Callback

void IService1Callback.ReceiveMessage(Service.Message Message)
{
 System.Threading.SendOrPostCallback s = new System.Threading.SendOrPostCallback(WorkItem_ReceiveMessage);
 SyncContext.Post(s, Message);
}

public void WorkItem_ReceiveMessage(object args)
{
 EventTopic Receive = WorkItem.EventTopics["RECEIVE_MESSAGE"];
 Receive.Fire(this, new EventArgs(), WorkItem, PublicationScope.Global);
}