Remoting CallContext 实现客户端识别

最近整理一个Remoting项目， 需要识别客户端。最先想到的是WCF的MessageHeader，WebService的SoapHeader，抑或是通过消息拦截能够加入额外的信息。 调查了下发现 Remoting 实现消息拦截还比较麻烦（需要实现RealProxy等，详细看这里：http://www.cnblogs.com/idior/articles/872380.html)。 好在 Remoting 里还有个小编叫 CallContext 的小编可以封送额外的信息，调用上下文在应用程序域边界被克隆，其数据槽不在其他逻辑线程上的调用上下文之间共享。 当然放入 CallContext 的数据需要实现 ILogicalThreadAffinative 接口。

Identity.cs
using Sy<a href="/tag/stem/" target="_blank" class="keywords">stem</a>; using Sy<a href="/tag/stem/" target="_blank" class="keywords">stem</a>.Runtime.Remoting.Messaging; namespace RemotingCommLib { [Serializable] public class Identity : ILogicalThreadAffinative { // 客户端标识 public string ClientID { get; set; } public string ExtensionData { get; set; } } }

服务端实现
using Sy<a href="/tag/stem/" target="_blank" class="keywords">stem</a>; using RemotingCommLib; using Sy<a href="/tag/stem/" target="_blank" class="keywords">stem</a>.Runtime.Remoting.Messaging; namespace RemotingServiceHost { public class Service : MarshalByRefObject,IService { public string GetServerTime() { Identity identity = CallContext.GetData("identity") as Identity; Console.WriteLine("Client[{0}] access.",identity.ClientID); return string.Format("Get message from server at {0:HH:mm:ss}",DateTime.<a href="/tag/Now/" target="_blank" class="keywords">Now</a>); } } }

客户端调用
 using Sy<a href="/tag/stem/" target="_blank" class="keywords">stem</a>; using Sy<a href="/tag/stem/" target="_blank" class="keywords">stem</a>.Runtime.Remoting; using RemotingCommLib; using Sy<a href="/tag/stem/" target="_blank" class="keywords">stem</a>.Runtime.Remoting.Messaging; using Sy<a href="/tag/stem/" target="_blank" class="keywords">stem</a>.Threading; namespace RemotingClient { class Program { static void Main(string[] args) { string con<a href="/tag/fig/" target="_blank" class="keywords">fig</a> = AppDomain.CurrentDomain.Setup@R_501_<a href="/tag/404/" target="_blank" class="keywords">404</a>[e-mail]<a href="/tag/fig/" target="_blank" class="keywords">fig</a>urationFile; RemotingCon<a href="/tag/fig/" target="_blank" class="keywords">fig</a>uration.Con<a href="/tag/fig/" target="_blank" class="keywords">fig</a>ure(con<a href="/tag/fig/" target="_blank" class="keywords">fig</a>,false); string url = RemotingCon<a href="/tag/fig/" target="_blank" class="keywords">fig</a>uration.GetRegisteredWellK<a href="/tag/Now/" target="_blank" class="keywords">Now</a>nClientTypes()[0].ObjectUrl; IService client = (IService)Activator.G<a href="/tag/eto/" target="_blank" class="keywords">eto</a>bject(typeof(IService),url); Identity identity = new Identity(); identity.ClientID = Guid.NewGuid().ToString(); CallContext.SetData("identity",identity); string reply = client.GetServerTime(); Console.WriteLine("Client {0}:{1}",identity.ClientID,reply); Thread.Sleep(1000); IService client1 = (IService)Activator.G<a href="/tag/eto/" target="_blank" class="keywords">eto</a>bject(typeof(IService),url); string reply1 = client1.GetServerTime(); Console.WriteLine("Client {0}:{1}",reply1); Console.Read(); } } }

启动两个客户端调用：

服务端通过 CallContext.GetData 取到了客户端的标识ID。通过这种方法，还可以实现用户名密码的验证。