其实在服务端Remoting可以像读取一个变量一样来获取到连接过来的客户端的IP，不过这个IP不是太容易的取到。

网上有一个解决方案就是使用配置文件来吸取IP地址，但是这个方案需要我们使用配置文件来使用Remoting，如果我们是代码形式的程序，那么怎样获取客户端IP呢。

Remoting、WebService底层都是用Socket来实现，Socket本身很容易的可以获取到IP地址，所以理论上Remoting获取客户端IP是通过的。

我们可以从吸取器入手来获取，假如我们使用TCP通道来通信，在服务端使用TcpServerChannel类，该类其实已支持了吸取器，构造函数如下：

public TcpServerChannel(string name, int port, IServerChannelSinkProvider sinkProvider);

TcpServerChannel类默认的吸取器是BinaryServerFormatterSinkProvider，而吸取器可以设置链表上的下一个吸取器，然后依次执行每一个吸取器。

我们可以得到如下的代码：

IServerChannelSinkProvider serverSink = new ClientIPServerSinkProvider();BinaryServerFormatterSinkProvider firstSink = new BinaryServerFormatterSinkProvider();firstSink.Next = serverSink;TcpServerChannel channel = new TcpServerChannel("tcpserver", port, firstSink);ChannelServices.RegisterChannel(channel, true);RemotingConfiguration.RegisterWellKnownServiceType(typeof(RemotableClass), "RemotableClass", WellKnownObjectMode.Singleton);

到这里，如果定义好了RemotableClass类，那么就可以直接取IP地址了：

	public class RemotableClass : MarshalByRefObject 	{		protected string getIPAddress()		{			System.Net.IPAddress ip = System.Runtime.Remoting.Messaging.CallContext.GetData("ClientIPAddress") as System.Net.IPAddress;			if (ip != null)			{				return ip.ToString();			}			return null;		}	}

如果不知道吸取器的代码，可以参考如下：

	public class ClientIPServerSinkProvider : IServerChannelSinkProvider	{		private IServerChannelSinkProvider next = null;		public ClientIPServerSinkProvider()		{		}		public ClientIPServerSinkProvider(IDictionary properties, ICollection providerData)		{		}		public void GetChannelData(IChannelDataStore channelData)		{		}		public IServerChannelSink CreateSink(IChannelReceiver channel)		{			IServerChannelSink nextSink = null;			if (next != null)			{				nextSink = next.CreateSink(channel);			}			return new ClientIPServerSink(nextSink);		}		public IServerChannelSinkProvider Next		{			get { return next; }			set { next = value; }		}	}	public class ClientIPServerSink : BaseChannelObjectWithProperties, IServerChannelSink, IChannelSinkBase	{		private IServerChannelSink _next;		public ClientIPServerSink(IServerChannelSink next)		{			_next = next;		}		public void AsyncProcessResponse(IServerResponseChannelSinkStack sinkStack, Object state, IMessage msg, ITransportHeaders headers, Stream stream)		{		}		public Stream GetResponseStream(IServerResponseChannelSinkStack sinkStack, Object state, IMessage msg, ITransportHeaders headers)		{			return null;		}		public System.Runtime.Remoting.Channels.ServerProcessing ProcessMessage(IServerChannelSinkStack sinkStack, IMessage requestMsg, ITransportHeaders requestHeaders, Stream requestStream, out IMessage responseMsg, out ITransportHeaders responseHeaders, out Stream responseStream)		{			if (_next != null)			{				IPAddress ip = requestHeaders[CommonTransportKeys.IPAddress] as IPAddress;				CallContext.SetData("ClientIPAddress", ip);				return _next.ProcessMessage(sinkStack, requestMsg, requestHeaders, requestStream, out responseMsg, out responseHeaders, out responseStream);			}			else			{				responseMsg = null;				responseHeaders = null;				responseStream = null;				return ServerProcessing.Complete;			}		}		public IServerChannelSink NextChannelSink		{			get			{				return _next; 			}			set			{				_next = value;			}		}	}

到这里就完成了。

Remoting获取客户端的外网IP地址