WCF双工实现

WCF双工实现

• • 服务端步骤
  • 客户端步骤

1. Windows Communication Foundation(WCF)是由微软发展的一组数据通信的应用程序开发接口
2. WCF双工：客户端请求服务端，服务端处理完后再主动调用客户端；

服务端步骤

1. 服务端：新增2个接口（1个服务契约接口、1个回调接口），1个服务契约接口派生实现类、配置文件新增配置、启动服务监听端口，

    //1 服务契约接口， (CallbackContract = typeof(ICallback)) 要实现双工这个一定要加上，指定服务锲约为 ICallback
    [ServiceContract(CallbackContract = typeof(ICallback))]
    public interface ICalculateService
    {
        //操作契约， IsOneWay = true 要实现双工这个一定要加上
        [OperationContract(IsOneWay = true)]
        void Add(int x, int y);
    }

	//2 回调接口，接口名称自定义
    public interface ICallback
    {
        //回调契约
        [OperationContract(IsOneWay =true)]
        void Show(int n);
    }
    
    //3 服务契约的实现类
    public class CalculateService : ICalculateService
    {
        public void Add(int x, int y)
        {
            int result = x + y;
            Thread.Sleep(2000);
            //通过客户端实例通道
            ICallback callback = OperationContext.Current.GetCallbackChannel<ICallback>();
            //对客户端调用
            callback.Show(result);
        }
    }

2. 服务端：WCF配置文件，在web.config/app.config里

<system.serviceModel>
		<behaviors>
			<serviceBehaviors>
				<!--WCF-->
				<behavior name="CalculateServicebehavior">
					<serviceDebug httpHelpPageEnabled="false"/>
					<serviceMetadata httpGetEnabled="false"/>
					<serviceTimeouts transactionTimeout="00:10:00"/>
					<serviceThrottling maxConcurrentCalls="1000" maxConcurrentInstances="1000" maxConcurrentSessions="1000"/>
				</behavior>
			</serviceBehaviors>
		</behaviors>

		<!--WCF-->
		<bindings>
			<netTcpBinding>
				<binding name="tcpbinding">
					<security mode="None">
						<transport clientCredentialType="None" protectionLevel="None"/>
					</security>
				</binding>
			</netTcpBinding>
		</bindings>

		<!--WCF-->
		<services>
			<service name="MySOA.Service.CalculateService" behaviorConfiguration="CalculateServicebehavior">
				<host>
					<baseAddresses>
						<add baseAddress="net.tcp://localhost:11111/CalculatorService"/>
					</baseAddresses>
				</host>
				<endpoint address="" binding="netTcpBinding" bindingConfiguration="tcpbinding" contract="MySOA.Interface.ICalculateService"/>
				<endpoint address="mex" binding="mexTcpBinding" contract="IMetadataExchange"/>
			</service>
		</services>
		
	</system.serviceModel>

3. 启动WCF服务，比如用控制台程序

        static void InitService()
        {
            List<ServiceHost> serviceHosts = new List<ServiceHost>()
            {
                new ServiceHost(typeof(CalculateService))
            };

            foreach (var serviceHost in serviceHosts)
            {
                serviceHost.Opened += (s, e) => { Console.WriteLine(serviceHost.GetType().Name + "启动了..."); };
                serviceHost.Open();

            }
            Console.WriteLine("输入任何字符，中止服务");
            Console.ReadKey();
            foreach (var serviceHost in serviceHosts)
            {
                serviceHost.Close();
            }
        }

客户端步骤

1. 引用——添加服务引用，输入服务端配置文件里的地址；
   
2. 创建一个类，继承服务引用里的Callback接口(MySOAClient.ICalculateServiceCallback)，并实现方法，此方法届时为服务端主动调用的；

    public class MyCallback : MySOAClient.ICalculateServiceCallback
    {
        public void Show(int n)
        {
            Console.WriteLine($"n:{n}");
        }
    }

3. 在主函数里创建MyCallback实例并作为参数传入CalculateServiceClient对象，最后调用服务端的方法Add；

        static void Main(string[] args)
        {
            MySOAClient.CalculateServiceClient client = null;
            try
            {
                InstanceContext context = new InstanceContext(new MyCallback());
                client = new MySOAClient.CalculateServiceClient(context);
                client.Add(3, 9);
                client.Close();
            }
            catch (Exception ex)
            {
                if (client != null)
                    client.Abort();
                Console.WriteLine(ex.Message);
            }
            Console.Read();
        }

4. 客户端启动后，调用Add方法，服务端收到并执行Add方法，再执行Callback，再实现对对客户端的回调；