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WCF心跳判断服务端及客户端是否掉线并实现重连接

2013-11-13 11:47 405 查看

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

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();
}
}
}