如何在使用简单TCP时为WCF启用压缩

Question

我使用WCF在不同计算机上的程序的两个相同副本之间传输信息，下面的代码在一台计算机上演示了这种方法。我知道.NET 4.5支持开箱即用的压缩，在这个问题中我看到了一个XML实现，但我不知道在这种情况下如何启用它。如何修改下面的程序以使用最少/最简单的更改进行压缩？

// Reference to System.ServiceModel
class Program
{
    static void Main(string[] args)
    {
        var server = new DemoWcfServer();
        var handler = new DemoWcfHandler();
        Uri serviceUri = new Uri("net.tcp://localhost/SimpleWcfDemo");
        var binding = new NetTcpBinding();
        binding.MaxBufferSize = 100000000;
        binding.MaxReceivedMessageSize = 100000000;
        var host = new ServiceHost(server, serviceUri);
        host.AddServiceEndpoint(typeof(IDemoWcfServer), binding, "");
        host.Open();
        var cf = new DuplexChannelFactory<IDemoWcfServer>(handler, binding, new EndpointAddress(serviceUri));
        IDemoWcfServer serviceProxy = cf.CreateChannel();
        serviceProxy.DoStuff(BigString('T', 1000000));
        Console.ReadKey();
    }
    static string BigString(char c, int n)
    {
        var sb = new StringBuilder();
        for (int i = 0; i < n; i++)
            sb.Append(c);
        return sb.ToString();
    }
    [ServiceContract(CallbackContract = typeof(IDemoWcfCallback))]
    public interface IDemoWcfServer
    {
        [OperationContract]
        void DoStuff(string content);
    }
    [ServiceBehavior(InstanceContextMode = InstanceContextMode.Single)]
    public class DemoWcfServer : IDemoWcfServer
    {
        public void DoStuff(string content)
        {
            Console.WriteLine("Content of " + content.Length + " length received remotely; processing...");
            IDemoWcfCallback callback = OperationContext.Current.GetCallbackChannel<IDemoWcfCallback>();
            Task.Run(async () =>
            {
                await Task.Delay(TimeSpan.FromSeconds(3));
                callback.NotifyStuffComplete(BigString('R', 1000000));
            });
        }
    }
    public interface IDemoWcfCallback
    {
        [OperationContract]
        void NotifyStuffComplete(string content);
    }
    public class DemoWcfHandler : IDemoWcfCallback
    {
        public void NotifyStuffComplete(string content)
        {
            Console.WriteLine("Response of " + content.Length + " length received");
        }
    }
}

Answer 1

要创建包含压缩（.NET 4.5+）的自定义绑定，请替换为：

var binding = new NetTcpBinding();
binding.MaxBufferSize = 100000000;
binding.MaxReceivedMessageSize = 100000000;

这个：

var binding = new CustomBinding();
var be1 = new BinaryMessageEncodingBindingElement();
be1.CompressionFormat = CompressionFormat.GZip;
binding.Elements.Add(be1);
var be2 = new TcpTransportBindingElement();
be2.MaxBufferSize = 100000000;
be2.MaxReceivedMessageSize = 100000000;
binding.Elements.Add(be2);
binding = new CustomBinding(binding);

通过监听到端口808的本地环回，可以使用Microsoft Message Analyzer（或者Wireshark）来验证所需的行为。在压缩的情况下，只交换了14个数据包，没有一个有效载荷大于1200字节。在没有压缩的情况下，有238个数据包，其中许多数据包大于64k。

Answer 2

问题的答案您的报价通过使用自定义绑定来解决它。你可以自己做这件事，正如MSDN文章中所解释的那样。