wcf客户间通信

悄悄话的功能其实是不难实现的， 看完下面的代码你就知道怎么做。

// InstanceContextMode.PerSession 服务器为每个客户会话创建一个新的上下文对象。ConcurrencyMode.Multiple 异步的多线程实例

[ServiceBehavior(InstanceContextMode = InstanceContextMode.PerSession, ConcurrencyMode = ConcurrencyMode.Multiple)]

public class ChatService : IChatService

{

private static Object syncObj = new Object();////定义一个静态对象用于线程部份代码块的锁定，用于lock操作

IChatCallback callback = null;

public delegate void ChatEventHandler(object sender, ChatEventArgs e);//定义用于把处理程序赋予给事件的委托。

public static event ChatEventHandler ChatEvent;//定义事件

static Dictionary<string, ChatEventHandler> chatters = new Dictionary<string, ChatEventHandler>();//创建一个静态Dictionary（表示键和值）集合(字典)，用于记录在线成员，Dictionary<(Of <(TKey, TValue>)>) 泛型类

private string name;

private ChatEventHandler myEventHandler = null;

public string[] Join(string name)

{

bool userAdded = false;

myEventHandler = new ChatEventHandler(MyEventHandler);//将MyEventHandler方法作为参数传递给委托

lock (syncObj)//线程的同步性，同步访问多个线程的任何变量，利用lock(独占锁)，确保数据访问的唯一性。

{

if (!chatters.ContainsKey(name) && name != "" && name != null)

{

this.name = name;

chatters.Add(name, MyEventHandler);

userAdded = true;

}

}

if (userAdded)

{

callback = OperationContext.Current.GetCallbackChannel<IChatCallback>();//获取当前操作客户端实例的通道给IChatCallback接口的实例callback,此通道是一个定义为IChatCallback类型的泛类型,通道的类型是事先服务契约协定好的双工机制。

ChatEventArgs e = new ChatEventArgs();//实例化事件消息类ChatEventArgs

e.msgType = MessageType.UserEnter;

e.name = name;

BroadcastMessage(e);

ChatEvent += myEventHandler;

string[] list = new string[chatters.Count]; //以下代码返回当前进入聊天室成员的称列表

lock (syncObj)

{

chatters.Keys.CopyTo(list, 0);//将字典中记录的用户信息复制到数组中返回。

}

return list;

}

else

{

return null;

}

}

public void Say(string msg)

{

ChatEventArgs e = new ChatEventArgs();

e.msgType = MessageType.Receive;

e.name = this.name;

e.message = msg;

BroadcastMessage(e);

}

public void Whisper(string to, string msg)

{

ChatEventArgs e = new ChatEventArgs();

e.msgType = MessageType.ReceiveWhisper;

e.name = this.name;

e.message = msg;

try

{

ChatEventHandler chatterTo;//创建一个临时委托实例

lock (syncObj)

{

chatterTo = chatters[to]; //查找成员字典中，找到要接收者的委托调用

}

chatterTo.BeginInvoke(this, e, new AsyncCallback(EndAsync), null);//异步方式调用接收者的委托调用

}

catch (KeyNotFoundException)

{

}

}

public void Leave()

{

if (this.name == null)

return;

lock (syncObj)

{

chatters.Remove(this.name);

}

ChatEvent -= myEventHandler;

ChatEventArgs e = new ChatEventArgs();

e.msgType = MessageType.UserLeave;

e.name = this.name;

this.name = null;

BroadcastMessage(e);

}

//回调，根据客户端动作通知对应客户端执行对应的操作

private void MyEventHandler(object sender, ChatEventArgs e)

{

try

{

switch (e.msgType)

{

case MessageType.Receive:

callback.Receive(e.name, e.message);

break;

case MessageType.ReceiveWhisper:

callback.ReceiveWhisper(e.name, e.message);

break;

case MessageType.UserEnter:

callback.UserEnter(e.name);

break;

case MessageType.UserLeave:

callback.UserLeave(e.name);

break;

}

}

catch

{

Leave();

}

}

private void BroadcastMessage(ChatEventArgs e)

{

ChatEventHandler temp = ChatEvent;

if (temp != null)

{

//循环将在线的用户广播信息

foreach (ChatEventHandler handler in temp.GetInvocationList())

{

//异步方式调用多路广播委托的调用列表中的ChatEventHandler

handler.BeginInvoke(this, e, new AsyncCallback(EndAsync), null);

}

}

}

//广播中线程调用完成的回调方法功能：清除异常多路广播委托的调用列表中异常对象（空对象）

private void EndAsync(IAsyncResult ar)

{

ChatEventHandler d = null;

try

{

//封装异步委托上的异步操作结果

System.Runtime.Remoting.Messaging.AsyncResult asres = (System.Runtime.Remoting.Messaging.AsyncResult)ar;

d = ((ChatEventHandler)asres.AsyncDelegate);

d.EndInvoke(ar);

}

catch

{

ChatEvent -= d;

}

}

}