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);
}
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);
}
}
}
//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();
}
}
