WCF 聊天室程序代码详细讲解教程

<xml version="1.0" encoding="utf-8" >
<configuration>
<appSettings>
<!--提供服务的通信协议、地址、端口、目录-->
<!--通信协议：net.tcp 、http 、-->
<add key="addr" value="net.tcp://localhost:22222/chatservice" />
</appSettings>
<system.serviceModel>
<services>
<!--服务名 = <命名空间>.<程序集名称>-->
<!--behaviorConfiguration 性能配置自定一个名称，<serviceBehaviors> 下的项对应此名称-->
<service name="NikeSoftChat.ChatService" behaviorConfiguration="MyBehavior">
<!--终节点-->
<!--binding 绑定类型,NetTcpBinding、WSDualHttpBinding、WSHttpBindingBase、BasicHttpBinding、NetNamedPipeBinding、NetPeerTcpBinding、MsmqBindingBase、NetPeerTcpBinding、WebHttpBinding、MailBindingBase、CustomBinding-->
<!--DuplexBinding 双工-->
<!--使用契约：<命名空间>.<接口名称>-->
<endpoint address=""
binding="netTcpBinding"
bindingConfiguration="DuplexBinding"
contract="NikeSoftChat.IChat" />
</service>
</services>
<behaviors>
<serviceBehaviors>
<behavior  name="MyBehavior">
<!--会话最大数量-->
<serviceThrottling maxConcurrentSessions="10000" />
</behavior>
</serviceBehaviors>
</behaviors>
<bindings>
<netTcpBinding>
<!--双工，超时设置-->
<binding name="DuplexBinding" sendTimeout="00:00:01">
<!--可靠会话-->
<reliableSession enabled="true" />
<!--安全模式-->
<security mode="None" />
</binding>
</netTcpBinding>
</bindings>
</system.serviceModel>
</configuration>

// Copyright (C) 2006 by Nikola Paljetak
using System;
using System.Collections;
using System.Collections.Generic;
using System.ServiceModel;
namespace NikeSoftChat
{
//服务契约
// SessionMode.Required  允许Session会话
// 双工协定时的回调协定类型为IChatCallback接口）
[ServiceContract(SessionMode = SessionMode.Required, CallbackContract = typeof(IChatCallback))]
interface IChat
{
//服务操作
// IsOneWay = false      等待服务器完成对方法处理
// IsInitiating = true   启动Session会话
// IsTerminating = false 设置服务器发送回复后不关闭会话
[OperationContract(IsOneWay = false, IsInitiating = true, IsTerminating = false)]
string[] Join(string name);
[OperationContract(IsOneWay = true, IsInitiating = false, IsTerminating = false)]
void Say(string msg);
[OperationContract(IsOneWay = true, IsInitiating = false, IsTerminating = false)]
void Whisper(string to, string msg);
//服务操作
// IsOneWay = true       不等待服务器完成对方法处理
// IsInitiating = false  不启动Session会话
// IsTerminating = true  关闭会话，在服务器发送回复后
[OperationContract(IsOneWay = true, IsInitiating = false, IsTerminating = true)]
void Leave();
}
interface IChatCallback
{
[OperationContract(IsOneWay = true)]
void Receive(string senderName, string message);
[OperationContract(IsOneWay = true)]
void ReceiveWhisper(string senderName, string message);
[OperationContract(IsOneWay = true)]
void UserEnter(string name);
[OperationContract(IsOneWay = true)]
void UserLeave(string name);
}
//定义一个客户端动作的枚举
public enum MessageType { Receive, UserEnter, UserLeave, ReceiveWhisper };
//定义一个本例的事件消息类
public class ChatEventArgs : EventArgs
{
public MessageType msgType;
public string name;
public string message;
}

// 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 : IChat //继承IChat接口或者说IChat的实现类
{
//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
private static Object syncObj = new Object();
//创建一个IChatCallback 回调接口实例,接口成员始终是公共的，所有没有访问修饰符
IChatCallback callback = null;
//定义一个委托
public delegate void ChatEventHandler(object sender, ChatEventArgs e);
//定义一个静态的委托事件
public static event ChatEventHandler ChatEvent;
//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
static Dictionary<string, ChatEventHandler> chatters = new Dictionary<string, ChatEventHandler>();
//当用客户的昵称
private string name;
//创建委托（ChatEventHandler）的一个空实例
private ChatEventHandler myEventHandler = null;
//成员进入聊天室
public string[] Join(string name)
{
bool userAdded = false;
//用MyEventHandler方法，实例化委托（ChatEventHandler）
myEventHandler = new ChatEventHandler(MyEventHandler);
//锁定，保持lock块中的代码段始终只有一个线程在调用，原因是ConcurrencyMode.Multiple 为异步的多线程实例，存在并发竞争问题
//如果不锁定，则静态成员字典chatters.ContainsKey(name) 的结果将会不确定，原因是每个线程都可以访问到它。以下凡是chatters 的操作匀加锁
//使用lock多个线程同时请示时，没有操作权的将会在线程池中等待至有操作权的线程执完成。lock 方法存在影响吞吐量的问题
lock (syncObj)
{
//如果请求的昵称在成员字典中不存在并不空
if (!chatters.ContainsKey(name) && name != "" && name != null)
{
this.name = name; //记录当前线程昵称
chatters.Add(name, MyEventHandler);//加入到成员字典key 为当前昵称，MyEventHandler 当前的委托调用
userAdded = true;
}
}
if (userAdded)
{
//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（见IChat前的ServiceContract）
callback = OperationContext.Current.GetCallbackChannel<IChatCallback>();
//实例化事件消息类ChatEventArgs，并对其赋值
ChatEventArgs e = new ChatEventArgs();
e.msgType = MessageType.UserEnter;
e.name = name;
//发送广播信息
BroadcastMessage(e);
//加入到多路广播委托的调用列表中,下面这条如果和上面一条位置互换，那么会收到自己进入聊天室的广播信息。
ChatEvent += myEventHandler;
//以下代码返回当前进入聊天室成员的称列表
string[] list = new string[chatters.Count];
lock (syncObj)
{
chatters.Keys.CopyTo(list, 0);//从成员字典索引0 开始复制chatters成员字典的key 值到list 字符串数组
}
return list;
}
else
{
//当昵称重复或为空是，如果客户端做了为空检测，则可直接认为是名称重复，当前要在没有异常的情况下。
return null;
}
}
//聊天室通信
public void Say(string msg)
{
ChatEventArgs e = new ChatEventArgs();
e.msgType = MessageType.Receive;
e.name = this.name;
e.message = msg;
BroadcastMessage(e);
}
//私有对话
public void Whisper(string to, string msg)
{
ChatEventArgs e = new ChatEventArgs();
e.msgType = MessageType.ReceiveWhisper;
e.name = this.name;
e.message = msg;
try
{
//创建一个临时委托实例
ChatEventHandler chatterTo;
lock (syncObj)
{
//查找成员字典中，找到要接收者的委托调用
chatterTo = chatters[to];
}
//异步方式调用接收者的委托调用
chatterTo.BeginInvoke(this, e, new AsyncCallback(EndAsync), null);
}
catch (KeyNotFoundException)
{
//访问集合中元素的键与集合中的任何键都不匹配时所引发的异常
}
}
//成员离开聊天室
public void Leave()
{
if (this.name == null)
return;
//删除成员字典中的当前会话的成员，及删除多路广播委托的调用列表中的当前调用
//name 和myEventHandler 的生存周期是在当前会话中一直存在的，参考Session 周期
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 //异常退出，或超时，或session过期
{
Leave();
}
}
//发送广播信息
//要点：根据上下文理解: 1 广播什么(what),2 为谁广播(who),3“谁”从哪来(where),4 如何来的(how)
private void BroadcastMessage(ChatEventArgs e)
{
//创建回调委托事件实例ChatEvent的一个副本，之所以用副本是因为ChatEvent处于多线程并状态(？此处不知理解是否正确,因为我理解后面的handler 是一个引用，自相矛盾了)
ChatEventHandler temp = ChatEvent;
if (temp != null)
{
//GetInvocationList方法，按照调用顺序返回“多路广播委托(MulticastDelegate)”的调用列表
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
//BeginInvoke方法异步调用，即不等等执行，详细说明则是：公共语言运行库(CLR) 将对请求进行排队并立即返回到调用方。将对来自线程池的线程调用该目标方法。
//EndAsync 为线程异步调用完成的回调方法，EndAsync 接收并操持着线程异步调用的操作状态,可通过此结果找到调用者，如此例handler，handler是一个委托实例的引用
//         此状态为调用者（委托）的事件声明类型此例为public event ChatEventHandler ChatEvent; 中的ChatEventHandler
//最后一个参数:包含的对象的状态信息，传递给委托;
handler.BeginInvoke(this, e,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;
//asres.AsyncDelegate 获取在异步调用asres 的委托对象，asres 来自对ar 的AsyncResult 封装，ar 来自线程异步调用的操作状态
d = ((ChatEventHandler)asres.AsyncDelegate);
//EndInvoke 返回由异步操作ar 生成的结果Object
d.EndInvoke(ar);
}
catch
{
ChatEvent -= d;
}
}
}
}

// Copyright (C) 2006 by Nikola Paljetak
using System;
using System.Collections.Generic;
using System.Text;
using System.ServiceModel;
using System.Configuration;
namespace NikeSoftChat
{
class Program
{
static void Main(string[] args)
{
Uri uri = new Uri(ConfigurationManager.AppSettings["addr"]);//获取配置
ServiceHost host = new ServiceHost(typeof(NikeSoftChat.ChatService), uri);
host.Open();
Console.WriteLine("Chat service listen on endpoint {0}", uri.ToString());
Console.WriteLine("Press ENTER to stop chat service...");
Console.ReadLine();
host.Abort();
host.Close();
}

}
}

<xml version="1.0" encoding="utf-8">
<!--这里的说明可以完全参考 service 的 app.config -->
<configuration>
<system.serviceModel>
<client>
<endpoint name=""
address="net.tcp://localhost:22222/chatservice"
binding="netTcpBinding"
bindingConfiguration="DuplexBinding"
contract="IChat" />
</client>
<bindings>
<netTcpBinding>
<!--这里的sendTimeout比服务端的要多出4秒，因为服务端不参入具体通信，它只是提供服务-->
<binding name="DuplexBinding" sendTimeout="00:00:05" >
<reliableSession enabled="true" />
<security mode="None" />
</binding>
</netTcpBinding>
</bindings>
</system.serviceModel>
</configuration>

// Copyright (C) 2006 by Nikola Paljetak
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.ServiceModel;

namespace NikeSoftChat
{
public partial class ChatForm : Form, IChatCallback
{
[DllImport("user32.dll")]
private static extern int SendMessage(IntPtr hWnd, int msg, int wParam, IntPtr lParam);
private const int WM_VSCROLL = 0x115;
private const int SB_BOTTOM = 7;
private int lastSelectedIndex = -1;
private ChatProxy proxy;//代理
private string myNick;  //当前我的昵称
private PleaseWaitDialog pwDlg; //状态窗口（显示等待与错误提示）
private delegate void HandleDelegate(string[] list);//委托
private delegate void HandleErrorDelegate();//委托
public ChatForm()
{
InitializeComponent();
ShowConnectMenuItem(true);
}
private void connectToolStripMenuItem_Click(object sender, EventArgs e)
{
lstChatters.Items.Clear();
NickDialog nickDlg = new NickDialog();
if (nickDlg.ShowDialog() == DialogResult.OK)
{
myNick = nickDlg.txtNick.Text;// 得到键入的当前昵称
nickDlg.Close();
}
txtMessage.Focus();
Application.DoEvents(); //强制处理当前队列的所有windows 消息，以名影响后面的通信，winForm程序要注意一下UI 线程的问题
//获取服务实例的上下文，为指定主机承载的服务初始化
InstanceContext site = new InstanceContext(this);
proxy = new ChatProxy(site); //初始服务实例
//BeginJoin 是svcutil工具自动生成的(如果你用工具的话，当然你也可以自己写)，还有一个EndJoin 也是。
//为什么会生成这两个我们并没有在服务契约中定义的接口呢？原因是服务契约中Join 接口定义了IsOneWay = false
//IsOneWay = false 则我们在配置中绑定的是duplex 双工(双通道)，指操作返回应答信息。
//duplex 双工并不会等待调用服务方法完成，而是立即返回。单工方式则为Request/Reply 本例中没有涉及
//自动生成BeginJoin 会比我们的Join 多两个参数，一个用来当BeginJoin请求在服务方完成后本地回调的方法，另一个获取作为BeginInvoke 方法调用的最后一个参数而提供的对象。
//BeginJoin 会请求服务方执行Join 方法。当Join代码执行完毕，触发回调方法OnEndJoin
IAsyncResult iar = proxy.BeginJoin(myNick, new AsyncCallback(OnEndJoin),null);
pwDlg = new PleaseWaitDialog();
pwDlg.ShowDialog();
}
private void OnEndJoin(IAsyncResult iar)
{
try
{
//EndJoin 请求服务方返回Join 执行后的返回值
//iar 异步调用的操作状态
//返回聊天室当前在线成员列表
string[] list = proxy.EndJoin(iar);
HandleEndJoin(list);
}
catch (Exception e)
{
HandleEndJoinError();
}
}
private void HandleEndJoinError()
{
//判断状态提示窗口是否在同一个线程内
if (pwDlg.InvokeRequired)
//对当前线程调用目标方法,此例调用本身
pwDlg.Invoke(new HandleErrorDelegate(HandleEndJoinError));
else
{
pwDlg.ShowError("Error: Cannot connect to chat!");
ExitChatSession();
}
}

//生成在线成员列表，当参数list为空时则表示当前昵称在在线成员列表中已存在
private void HandleEndJoin(string[] list)
{
//状态提示窗口是否运行在同一个线程
if (pwDlg.InvokeRequired)
pwDlg.Invoke(new HandleDelegate(HandleEndJoin), new object[] { list });
else
{
if (list == null)
{
pwDlg.ShowError("Error: Username already exist!");
ExitChatSession();
}
else
{
pwDlg.Close();
ShowConnectMenuItem(false);
foreach (string name in list)
{
lstChatters.Items.Add(name);
}
AppendText("Connected at " + DateTime.Now.ToString() + " with user name " + myNick + Environment.NewLine);
}
}
}
//发送信息
private void SayAndClear(string to, string msg, bool pvt)
{
if (msg != "")
{
try
{
CommunicationState cs = proxy.State;
//pvt 公聊还是私聊
if (!pvt)
proxy.Say(msg); //发送信息
else
proxy.Whisper(to, msg);//对指定者发送信息
txtMessage.Text = "";
}
catch
{
AbortProxyAndUpdateUI();
AppendText("Disconnected at " + DateTime.Now.ToString() + Environment.NewLine);
Error("Error: Connection to chat server lost!");
}
}
}

private void Error(string errMessage)
{
MessageBox.Show(errMessage, "Connection error", MessageBoxButtons.OK, MessageBoxIcon.Error);
ExitChatSession();
}
private void btnSay_Click(object sender, EventArgs e)
{
SayAndClear("", txtMessage.Text, false);
txtMessage.Focus();
}
private void btnWhisper_Click(object sender, EventArgs e)
{
if (txtMessage.Text == "")
return;
object to = lstChatters.SelectedItem;
if (to != null)
{
string receiverName = (string)to;
AppendText("Whisper to " + receiverName + ": " + txtMessage.Text + Environment.NewLine);
SayAndClear(receiverName, txtMessage.Text, true);
txtMessage.Focus();
}
}
private void disconnectToolStripMenuItem_Click(object sender, EventArgs e)
{
ExitChatSession();
btnWhisper.Enabled = false;
AppendText("Disconnected at " + DateTime.Now.ToString() + Environment.NewLine);
}
#region IChatCallback 实现接口成员
//接收公聊时
public void Receive(string senderName, string message)
{
AppendText(senderName + ": " + message + Environment.NewLine);
}
//接收私聊时
public void ReceiveWhisper(string senderName, string message)
{
AppendText(senderName + " whisper: " + message + Environment.NewLine);
}
//其他人进入聊天室时
public void UserEnter(string name)
{
AppendText("User " + name + " enter at " + DateTime.Now.ToString() + Environment.NewLine);
lstChatters.Items.Add(name);
}
//其他人退出聊天室时
public void UserLeave(string name)
{
AppendText("User " + name + " leave at " + DateTime.Now.ToString() + Environment.NewLine);
lstChatters.Items.Remove(name);
AdjustWhisperButton();
}
#endregion
private void AppendText(string text)
{
txtChatText.Text += text;
//txtChatText 滚动条始终定位于最下面
SendMessage(txtChatText.Handle, WM_VSCROLL, SB_BOTTOM, new IntPtr(0));
}
//菜单项"连接"与"断开"的显/隐控制（）
private void ShowConnectMenuItem(bool show)
{
connectToolStripMenuItem.Enabled = show;
disconnectToolStripMenuItem.Enabled = btnSay.Enabled = !show;
}
private void txtMessage_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyData == Keys.Enter && btnSay.Enabled)
{
SayAndClear("", txtMessage.Text, false);
}
}
private void exitToolStripMenuItem_Click(object sender, EventArgs e)
{
ExitChatSession();
ExitApplication();
}
private void ChatForm_FormClosed(object sender, FormClosedEventArgs e)
{
ExitChatSession();
ExitApplication();
}
//退出聊天室会话
private void ExitChatSession()
{
try
{
//离开通知
proxy.Leave();
}
catch { }
finally
{
AbortProxyAndUpdateUI();
}
}
//中断代理并更新UI
private void AbortProxyAndUpdateUI()
{
if (proxy != null)
{
proxy.Abort();
proxy.Close();
proxy = null;
}
ShowConnectMenuItem(true);
}

private void ExitApplication()
{
Application.Exit();
}
private void txtMessage_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == 13)
{
e.Handled = true;
btnSay.PerformClick();
}
}
private void lstChatters_SelectedIndexChanged(object sender, EventArgs e)
{
AdjustWhisperButton();
}
private void AdjustWhisperButton()
{
if (lstChatters.SelectedIndex == lastSelectedIndex)
{
lstChatters.SelectedIndex = -1;
lastSelectedIndex = -1;
btnWhisper.Enabled = false;
}
else
{
btnWhisper.Enabled = true;
lastSelectedIndex = lstChatters.SelectedIndex;
}
txtMessage.Focus();
}
private void ChatForm_Resize(object sender, EventArgs e)
{
//txtChatText 滚动条始终定位于最下面
SendMessage(txtChatText.Handle, WM_VSCROLL, SB_BOTTOM, new IntPtr(0));
}

}
}