三、程序的实现
服务器端核心代码：
// 启动服务器
// 根据博客中协议的设计部分
// 客户端先向服务器发送登录请求，然后通过服务器返回的端口号
// 再与服务器建立连接
// 所以启动服务按钮事件中有两个套接字：一个是接收客户端信息套接字和
// 监听客户端连接套接字
private void btnStart_Click(object sender, EventArgs e)
{
// 创建接收套接字
serverIp = IPAddress.Parse(txbServerIP.Text);
serverIPEndPoint = new IPEndPoint(serverIp, int.Parse(txbServerport.Text));
receiveUdpClient = new UdpClient(serverIPEndPoint);
// 启动接收线程
Thread receiveThread = new Thread(ReceiveMessage);
receiveThread.Start();
btnStart.Enabled = false;
btnStop.Enabled = true;
// 随机指定监听端口
Random random = new Random();
tcpPort = random.Next(port + 1, 65536);
// 创建监听套接字
tcpListener = new TcpListener(serverIp, tcpPort);
tcpListener.Start();
// 启动监听线程
Thread listenThread = new Thread(ListenClientConnect);
listenThread.Start();
AddItemToListBox(string.Format("服务器线程{0}启动，监听端口{1}",serverIPEndPoint,tcpPort));
}
// 接收客户端发来的信息
private void ReceiveMessage()
{
IPEndPoint remoteIPEndPoint = new IPEndPoint(IPAddress.Any, 0);
while (true)
{
try
{
// 关闭receiveUdpClient时下面一行代码会产生异常
byte[] receiveBytes = receiveUdpClient.Receive(ref remoteIPEndPoint);
string message = Encoding.Unicode.GetString(receiveBytes, 0, receiveBytes.Length);
// 显示消息内容
AddItemToListBox(string.Format("{0}:{1}",remoteIPEndPoint,message));
// 处理消息数据
// 根据协议的设计部分，从客户端发送来的消息是具有一定格式的
// 服务器接收消息后要对消息做处理
string[] splitstring = message.Split(',');
// 解析用户端地址
string[] splitsubstring = splitstring[2].Split(':');
IPEndPoint clientIPEndPoint = new IPEndPoint(IPAddress.Parse(splitsubstring[0]), int.Parse(splitsubstring[1]));
switch (splitstring[0])
{
// 如果是登录信息，向客户端发送应答消息和广播有新用户登录消息
case "login":
User user = new User(splitstring[1], clientIPEndPoint);
// 往在线的用户列表添加新成员
userList.Add(user);
AddItemToListBox(string.Format("用户{0}({1})加入", user.GetName(), user.GetIPEndPoint()));
string sendString = "Accept," + tcpPort.ToString();
// 向客户端发送应答消息
SendtoClient(user, sendString);
AddItemToListBox(string.Format("向{0}({1})发出：[{2}]", user.GetName(), user.GetIPEndPoint(), sendString));
for (int i = 0; i < userList.Count; i++)
{
if (userList[i].GetName() != user.GetName())
{
// 给在线的其他用户发送广播消息
// 通知有新用户加入
SendtoClient(userList[i], message);
}
}
AddItemToListBox(string.Format("广播：[{0}]", message));
break;
case "logout":
for (int i = 0; i < userList.Count; i++)
{
if (userList[i].GetName() == splitstring[1])
{
AddItemToListBox(string.Format("用户{0}({1})退出",userList[i].GetName(),userList[i].GetIPEndPoint()));
userList.RemoveAt(i); // 移除用户
}
}
for (int i = 0; i < userList.Count; i++)
{
// 广播注销消息
SendtoClient(userList[i], message);
}
AddItemToListBox(string.Format("广播:[{0}]", message));
break;
}
}
catch
{
// 发送异常退出循环
break;
}
}
AddItemToListBox(string.Format("服务线程{0}终止", serverIPEndPoint));
}
// 向客户端发送消息
private void SendtoClient(User user, string message)
{
// 匿名方式发送
sendUdpClient = new UdpClient(0);
byte[] sendBytes = Encoding.Unicode.GetBytes(message);
IPEndPoint remoteIPEndPoint =user.GetIPEndPoint();
sendUdpClient.Send(sendBytes,sendBytes.Length,remoteIPEndPoint);
sendUdpClient.Close();
}
// 接受客户端的连接
private void ListenClientConnect()
{
TcpClient newClient = null;
while (true)
{
try
{
newClient = tcpListener.AcceptTcpClient();
AddItemToListBox(string.Format("接受客户端{0}的TCP请求",newClient.Client.RemoteEndPoint));
}
catch
{
AddItemToListBox(string.Format("监听线程({0}:{1})", serverIp, tcpPort));
break;
}
Thread sendThread = new Thread(SendData);
sendThread.Start(newClient);
}
}
// 向客户端发送在线用户列表信息
// 服务器通过TCP连接把在线用户列表信息发送给客户端
private void SendData(object userClient)
{
TcpClient newUserClient = (TcpClient)userClient;
userListstring = null;
for (int i = 0; i < userList.Count; i++)
{
userListstring += userList[i].GetName() + ","
+ userList[i].GetIPEndPoint().ToString() + ";";
}
userListstring += "end";
networkStream = newUserClient.GetStream();
binaryWriter = new BinaryWriter(networkStream);
binaryWriter.Write(userListstring);
binaryWriter.Flush();
AddItemToListBox(string.Format("向{0}发送[{1}]", newUserClient.Client.RemoteEndPoint, userListstring));
binaryWriter.Close();
newUserClient.Close();
}
