WCF 学习笔记之双工实现

 

其中 Client 和Service为控制台程序 Service.Interface为类库

首先了解契约Interface两个接口

using System.ServiceModel;using System.ServiceModel.Channels;namespace Artech.WcfServices.Service.Interface{    [ServiceContract(Namespace = "http://www.artech.com/", CallbackContract = typeof(ICalculatorCallback))]    public interface ICalculator    {        [OperationContract(IsOneWay = true)]        void Add(double x, double y);    }}

这边要注意两个地方：一个是明确回调查的接口，和设置让它为单向模式[CallbackContract = typeof(ICalculatorCallback)]；IsOneWay = true

回调接口的代码如下：     

using System.ServiceModel;namespace Artech.WcfServices.Service.Interface{    public interface ICalculatorCallback    {        [OperationContract(IsOneWay = true)]        void DisplayResult(double result, double x, double y);    }}

此处也有两个地方要注意：回调契约没有定义[ServiceContact]的特性是因为在指定CallbackContract属性时就隐含对应的接口是个服务契约；此外同样也要设置为单向IsOneWay = true

接下来是服务实现层的代码：

using System.ServiceModel;using Artech.WcfServices.Service.Interface;using System.Threading;namespace Artech.WcfServices.Service{    public class CalculatorService : ICalculator    {        public void Add(double x, double y)        {            double result = x + y;            ICalculatorCallback callback = OperationContext.Current.GetCallbackChannel<ICalculatorCallback>();            callback.DisplayResult(result, x, y);        }    }}

相对应的App.config配置

<?xml version="1.0" encoding="utf-8" ?><configuration>  <system.serviceModel>        <behaviors>      <serviceBehaviors>        <behavior name="exposeExceptionDetail">          <serviceDebug includeExceptionDetailInFaults="true"/>        </behavior>      </serviceBehaviors>    </behaviors>    <services>      <service name="Artech.WcfServices.Service.CalculatorService"               behaviorConfiguration="exposeExceptionDetail">        <endpoint address="net.tcp://127.0.0.1:3721/calculatorservice"                  binding="netTcpBinding"                  contract="Artech.WcfServices.Service.Interface.ICalculator"/>      </service>    </services>  </system.serviceModel></configuration>

关于绑定类型的选择必须明确是支持双向通信的类型才可以；比如NetTcpBinding,WSDualHttpBinding ;这边应该注意在采用WSDualHttpBinding时要把可靠会话打开，因为它是通过可靠会话维护两个HTTP通道之间的匹配；
例如：<reliableSession enabled="true"/>

<?xml version="1.0" encoding="utf-8" ?><configuration>  <system.serviceModel>    <bindings>      <netTcpBinding>        <binding name="reliableSessionBinding">          <reliableSession enabled="true"/>        </binding>      </netTcpBinding>    </bindings>    <behaviors>      <serviceBehaviors>        <behavior name="exposeExceptionDetail">          <serviceDebug includeExceptionDetailInFaults="true"/>        </behavior>      </serviceBehaviors>    </behaviors>    <services>      <service name="Artech.WcfServices.Service.CalculatorService"               behaviorConfiguration="exposeExceptionDetail">        <endpoint address="net.tcp://127.0.0.1:3721/calculatorservice"                  binding="netTcpBinding"                  bindingConfiguration="reliableSessionBinding"                  contract="Artech.WcfServices.Service.Interface.ICalculator"/>      </service>    </services>  </system.serviceModel></configuration>

服务层还有一个代码就是宿主打开

using System.ServiceModel;using Artech.WcfServices.Service.Interface;using System.Threading;using System.ServiceModel.Description;namespace Artech.WcfServices.Service{    class Program    {        static void Main(string[] args)        {            using (ServiceHost host = new ServiceHost(typeof(CalculatorService)))            {                host.Open();                Console.Read();            }        }    }}

接下来是客户端的实现，要实现回调接口的

using Artech.WcfServices.Service.Interface;namespace Artech.WcfServices.Client{    public class CalculatorCallbackService : ICalculatorCallback    {        public void DisplayResult(double result, double x, double y)        {            Console.WriteLine("x + y = {2} when x = {0}  and y = {1}", x, y, result);        }    }}

以及相对应的配置文件内容：

<?xml version="1.0" encoding="utf-8" ?><configuration>  <system.serviceModel>        <client>      <endpoint name ="calculatorservice"                address="net.tcp://127.0.0.1:3721/calculatorservice"                binding="netTcpBinding"                contract="Artech.WcfServices.Service.Interface.ICalculator"/>    </client>  </system.serviceModel></configuration>

以及运行的代码：

using System.ServiceModel;using Artech.WcfServices.Service.Interface;using System.ServiceModel.Channels;using System.Threading;namespace Artech.WcfServices.Client{    class Program    {        static void Main(string[] args)        {            InstanceContext callback = new InstanceContext(new CalculatorCallbackService());            using (DuplexChannelFactory<ICalculator> channelFactory = new DuplexChannelFactory<ICalculator>(callback, "calculatorservice"))            {                ICalculator calculator = channelFactory.CreateChannel();                calculator.Add(1, 2);            }            Console.Read();        }    }}

针对TCP协议要把服务器的相对应服务打开；或者可能会报错；

错误一：TransportManager 无法使用 NetTcpPortSharing 服务侦听提供的 URI: 无法启动服务，因为该服务已禁用。管理员运行 "sc.exe config NetTcpPortSharing start= demand" 可以将其启用 [NetTcpPortSharing 服务没有启动]

错误二：TransportManager 无法使用 NetTcpPortSharing 服务侦听提供的 URI: 服务侦听失败 [端口被占用，换个端口]