WCF心跳判断服务端及客户端是否掉线并实现重连接

本文主要是介绍WCF心跳判断服务端及客户端是否掉线并实现重连接，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

本篇文章将通过一个实例实现对WCF中针对服务端以及客户端是否掉线进行判断；若掉线时服务器或客户端又在线时将实现自动重连；将通过WCF的双工知识以及相应的心跳包来实现此功能；

首先了解一下本实例的一个分层架构图；相信了解WCF对这个分层法肯定都很了解；其中Client为客户端，Interface为契约层，Service则是实现契约的服务层；

接下来我们将对各层进行一个简单的讲解；方便大家理解实例的实现方式；

首先我们了解契约层Interface；因为我们利用WCF中的双工知识，所以此处我们定义的两个接口，其中ICallback为回调接口；IPushMessage上面定义的回调；我们发现回调接口上并没有定义ServiceContract; 其实是WCF当一个接口被定义成回调接口时已经默认了；

using System.ServiceModel;
namespace Interface
{[ServiceContract(SessionMode=SessionMode.Required,CallbackContract=typeof(ICallback))]public interface IPushMessage{[OperationContract(IsOneWay = true)]void Login(string UID);[OperationContract(IsOneWay = true)]void Update(string UID);[OperationContract(IsOneWay = true)]void Leave(string UID);}
}

using System.ServiceModel;
namespace Interface
{public interface ICallback{[OperationContract(IsOneWay = true)]void ShowMessage(string msg);}
}

接着我们了解一下实现契约的服务层Service;此处包括实现接口IPushMessage的服务内容，还定义一个类WcfCleint；在PushMessageServer服务内里我们定义的一个静态成员Dictionary<string,WcfCleint>用于记录我们客户端上下线的操作；定义的一个lockObje用来锁定每个操作,在最后我们还定义的一个定时器用来判断客户端用户是否脱机了；其中方法Update()我们就实现的双工中的回调；

using System.ServiceModel;
using Interface;
namespace Service
{public class PushMessageServer:IPushMessage{static Dictionary<string, WcfCleint> dit_callback = new Dictionary<string, WcfCleint>();private static Object lockObje = new Object();public void Login(string UID){Console.WriteLine("用户:" + UID + "上线");lock (lockObje){dit_callback.Add(UID, new WcfCleint(OperationContext.Current.GetCallbackChannel<ICallback>(), DateTime.Now));}}public void Update(string UID){ICallback callback = OperationContext.Current.GetCallbackChannel<ICallback>();Console.WriteLine("用户:" + UID + "心跳更新！");lock (lockObje){if (dit_callback.ContainsKey(UID)){dit_callback.Remove(UID);}dit_callback.Add(UID, new WcfCleint(OperationContext.Current.GetCallbackChannel<ICallback>(), DateTime.Now));callback.ShowMessage(UID);}}public void Leave(string UID){Console.WriteLine("用户:" + UID + "退出！");lock (lockObje){dit_callback.Remove(UID);}}static System.Timers.Timer timer1;public static void StartListenClients(){timer1 = new System.Timers.Timer();timer1.Interval = 500;timer1.Elapsed += new System.Timers.ElapsedEventHandler(time_EventArgs);timer1.Start();}static void time_EventArgs(object sender, System.Timers.ElapsedEventArgs e){lock (lockObje){foreach (string key in new List<string>(dit_callback.Keys)){if (dit_callback[key].NowdateTime.AddSeconds(5) < DateTime.Now){dit_callback.Remove(key);Console.WriteLine("脱机用户" + key);}}}}}
}

接着我们简单看一下WcfCleint的代码：

using Interface;
using System.ServiceModel;
namespace Service
{public class WcfCleint{public DateTime NowdateTime { get; set; }public ICallback callbackHandler { get; set; }public WcfCleint(ICallback callback, DateTime nowTime){this.callbackHandler = callback;this.NowdateTime = nowTime;}}
}

服务端的配置文件信息，此处我们采用net.tcp方式：

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

服务端的运行入口代码，通过一个线程不断的运行：

using System.Threading;
using System.ServiceModel.Description;
namespace Service
{class Program{static void Main(string[] args){using (ServiceHost host = new ServiceHost(typeof(PushMessageServer))){host.Open();Console.WriteLine("WCF心跳包实现开始监听");PushMessageServer.StartListenClients();int i = 0;while (true){System.Threading.Thread.Sleep(2000);i++;}Console.Read();host.Abort();host.Close();}}}
}

接着了解客户端层的情况；首先是一个实现的回调接口的内容类；

using Interface;
namespace Client
{public class CallServer:ICallback{public void ShowMessage(string msg){Console.WriteLine("服务器正在工作中；" + msg);}}
}

客户端的配置信息如下：

<?xml version="1.0" encoding="utf-8" ?>
<configuration><system.serviceModel><client><endpoint name="pushmessageserver"address="net.tcp://127.0.0.1:3721/PushMessageServer"binding="netTcpBinding"contract="Interface.IPushMessage"/></client></system.serviceModel>
</configuration>

客户端的运行入口代码如下，它会判断服务器是否掉线，若掉线会试着重连：

using System.ServiceModel;
using Interface;
using System.ServiceModel.Channels;
using System.Threading;
namespace Client
{class Program{static void Main(string[] args){InstanceContext callback = new InstanceContext(new CallServer());using (DuplexChannelFactory<IPushMessage> channelFactory = new DuplexChannelFactory<IPushMessage>(callback, "pushmessageserver")){IPushMessage proxy = channelFactory.CreateChannel();using (proxy as IDisposable){string UID = "踏浪帅";proxy.Login(UID);while (true){Thread.Sleep(3000);try{proxy.Update(UID);}catch{try{Console.WriteLine("正在重连");proxy = channelFactory.CreateChannel();proxy.Login(UID);}catch{Console.WriteLine("重连异常");}}}}}Console.Read();}}
}