我正在尝试构建一个命令行聊天室，其中服务器正在处理连接并重复从一个客户端返回到所有其他客户端的输入。 目前，服务器能够从多个客户端接收输入，但只能单独将信息发送回这些客户端。我认为我的问题是每个连接都是在一个单独的线程上处理的。我如何允许线程相互通信或能够将数据发送到每个线程？
服务器代码：
namespace ConsoleApplication
{
class TcpHelper
{
private static object _lock = new object();
private static List<Task> _connections = new List<Task>();
private static TcpListener listener { get; set; }
private static bool accept { get; set; } = false;
private static Task StartListener()
{
return Task.Run(async () =>
{
IPAddress address = IPAddress.Parse("127.0.0.1");
int port = 5678;
listener = new TcpListener(address, port);
listener.Start();
Console.WriteLine($"Server started. Listening to TCP clients at 127.0.0.1:{port}");
while (true)
{
var tcpClient = await listener.AcceptTcpClientAsync();
Console.WriteLine("Client has connected");
var task = StartHandleConnectionAsync(tcpClient);
if (task.IsFaulted)
task.Wait();
}
});
}
// Register and handle the connection
private static async Task StartHandleConnectionAsync(TcpClient tcpClient)
{
// start the new connection task
var connectionTask = HandleConnectionAsync(tcpClient);
// add it to the list of pending task
lock (_lock)
_connections.Add(connectionTask);
// catch all errors of HandleConnectionAsync
try
{
await connectionTask;
}
catch (Exception ex)
{
// log the error
Console.WriteLine(ex.ToString());
}
finally
{
// remove pending task
lock (_lock)
_connections.Remove(connectionTask);
}
}
private static async Task HandleConnectionAsync(TcpClient client)
{
await Task.Yield();
{
using (var networkStream = client.GetStream())
{
if (client != null)
{
Console.WriteLine("Client connected. Waiting for data.");
StreamReader streamreader = new StreamReader(networkStream);
StreamWriter streamwriter = new StreamWriter(networkStream);
string clientmessage = "";
string servermessage = "";
while (clientmessage != null && clientmessage != "quit")
{
clientmessage = await streamreader.ReadLineAsync();
Console.WriteLine(clientmessage);
servermessage = clientmessage;
streamwriter.WriteLine(servermessage);
streamwriter.Flush();
}
Console.WriteLine("Closing connection.");
networkStream.Dispose();
}
}
}
}
public static void Main(string[] args)
{
// Start the server
Console.WriteLine("Hit Ctrl-C to close the chat server");
TcpHelper.StartListener().Wait();
}
}
}
客户代码：
namespace Client2
{
public class Program
{
private static void clientConnect()
{
TcpClient socketForServer = new TcpClient();
bool status = true;
string userName;
Console.Write("Input Username: ");
userName = Console.ReadLine();
try
{
IPAddress address = IPAddress.Parse("127.0.0.1");
socketForServer.ConnectAsync(address, 5678);
Console.WriteLine("Connected to Server");
}
catch
{
Console.WriteLine("Failed to Connect to server{0}:999", "localhost");
return;
}
NetworkStream networkStream = socketForServer.GetStream();
StreamReader streamreader = new StreamReader(networkStream);
StreamWriter streamwriter = new StreamWriter(networkStream);
try
{
string clientmessage = "";
string servermessage = "";
while (status)
{
Console.Write(userName + ": ");
clientmessage = Console.ReadLine();
if ((clientmessage == "quit") || (clientmessage == "QUIT"))
{
status = false;
streamwriter.WriteLine("quit");
streamwriter.WriteLine(userName + " has left the conversation");
streamwriter.Flush();
}
if ((clientmessage != "quit") && (clientmessage != "quit"))
{
streamwriter.WriteLine(userName + ": " + clientmessage);
streamwriter.Flush();
servermessage = streamreader.ReadLine();
Console.WriteLine("Server:" + servermessage);
}
}
}
catch
{
Console.WriteLine("Exception reading from the server");
}
streamreader.Dispose();
networkStream.Dispose();
streamwriter.Dispose();
}
public static void Main(string[] args)
{
clientConnect();
}
}
}
答案 0 :(得分：2)
您的代码中的主要问题是您不会尝试将从一个客户端收到的数据发送到其他连接的客户端。您的服务器中有_connections列表，但列表中唯一存储的是连接的Task对象，您甚至不对它们执行任何操作。
相反，您应该自己维护一个连接列表，这样当您从一个客户端收到消息时，您就可以将该消息重新传输给其他客户端。
至少应该是List<TcpClient>，但由于您使用的是StreamReader和StreamWriter，因此您还需要在列表中初始化并存储这些对象。此外，您应该包含客户端标识符。一个明显的选择是客户端的名称（即用户输入的名称），但是您的示例没有在聊天协议中提供任何机制来传输该标识作为连接初始化的一部分，所以在我的示例（下面）我只使用一个简单的整数值。
您发布的代码中存在其他一些违规行为，例如：
Task.Run()部分，因为它不是必需的。IsFaulted的特定于连接的任务。由于在返回此Task对象时，实际上不太可能发生任何I / O，因此该逻辑几乎没有用处。对Wait()的调用将抛出异常，该异常将传播到主线程的Wait()调用，终止服务器。但是，如果出现任何其他错误，您不会终止服务器，因此不清楚为什么要在此处执行此操作。Task.Yield()进行了虚假的调用。我不知道你想在那里完成什么，但不管它是什么，这个说法都没用。我只是将其删除了。我的版本如下：
服务器：
class TcpHelper
{
class ClientData : IDisposable
{
private static int _nextId;
public int ID { get; private set; }
public TcpClient Client { get; private set; }
public TextReader Reader { get; private set; }
public TextWriter Writer { get; private set; }
public ClientData(TcpClient client)
{
ID = _nextId++;
Client = client;
NetworkStream stream = client.GetStream();
Reader = new StreamReader(stream);
Writer = new StreamWriter(stream);
}
public void Dispose()
{
Writer.Close();
Reader.Close();
Client.Close();
}
}
private static readonly object _lock = new object();
private static readonly List<ClientData> _connections = new List<ClientData>();
private static TcpListener listener { get; set; }
private static bool accept { get; set; }
public static async Task StartListener()
{
IPAddress address = IPAddress.Any;
int port = 5678;
listener = new TcpListener(address, port);
listener.Start();
Console.WriteLine("Server started. Listening to TCP clients on port {0}", port);
while (true)
{
var tcpClient = await listener.AcceptTcpClientAsync();
Console.WriteLine("Client has connected");
var task = StartHandleConnectionAsync(tcpClient);
if (task.IsFaulted)
task.Wait();
}
}
// Register and handle the connection
private static async Task StartHandleConnectionAsync(TcpClient tcpClient)
{
ClientData clientData = new ClientData(tcpClient);
lock (_lock) _connections.Add(clientData);
// catch all errors of HandleConnectionAsync
try
{
await HandleConnectionAsync(clientData);
}
catch (Exception ex)
{
// log the error
Console.WriteLine(ex.ToString());
}
finally
{
lock (_lock) _connections.Remove(clientData);
clientData.Dispose();
}
}
private static async Task HandleConnectionAsync(ClientData clientData)
{
Console.WriteLine("Client connected. Waiting for data.");
string clientmessage;
while ((clientmessage = await clientData.Reader.ReadLineAsync()) != null && clientmessage != "quit")
{
string message = "From " + clientData.ID + ": " + clientmessage;
Console.WriteLine(message);
lock (_lock)
{
// Locking the entire operation ensures that a) none of the client objects
// are disposed before we can write to them, and b) all of the chat messages
// are received in the same order by all clients.
foreach (ClientData recipient in _connections.Where(r => r.ID != clientData.ID))
{
recipient.Writer.WriteLine(message);
recipient.Writer.Flush();
}
}
}
Console.WriteLine("Closing connection.");
}
}
客户端：
class Program
{
private const int _kport = 5678;
private static async Task clientConnect()
{
IPAddress address = IPAddress.Loopback;
TcpClient socketForServer = new TcpClient();
string userName;
Console.Write("Input Username: ");
userName = Console.ReadLine();
try
{
await socketForServer.ConnectAsync(address, _kport);
Console.WriteLine("Connected to Server");
}
catch (Exception e)
{
Console.WriteLine("Failed to Connect to server {0}:{1}", address, _kport);
return;
}
using (NetworkStream networkStream = socketForServer.GetStream())
{
var readTask = ((Func<Task>)(async () =>
{
using (StreamReader reader = new StreamReader(networkStream))
{
string receivedText;
while ((receivedText = await reader.ReadLineAsync()) != null)
{
Console.WriteLine("Server:" + receivedText);
}
}
}))();
using (StreamWriter streamwriter = new StreamWriter(networkStream))
{
try
{
while (true)
{
Console.Write(userName + ": ");
string clientmessage = Console.ReadLine();
if ((clientmessage == "quit") || (clientmessage == "QUIT"))
{
streamwriter.WriteLine(userName + " has left the conversation");
streamwriter.WriteLine("quit");
streamwriter.Flush();
break;
}
else
{
streamwriter.WriteLine(userName + ": " + clientmessage);
streamwriter.Flush();
}
}
await readTask;
}
catch (Exception e)
{
Console.WriteLine("Exception writing to server: " + e);
throw;
}
}
}
}
public static void Main(string[] args)
{
clientConnect().Wait();
}
}
你还需要做很多工作。您可能希望在服务器端实现正确的聊天用户名初始化。至少，对于真实世界的代码，您需要进行更多的错误检查，并确保可靠地生成客户端ID（如果您只想要正ID值，则不能超过2 ^ 31-1连接回滚到0之前的连接。
我还做了一些其他非必要的小改动，例如使用IPAddress.Any和IPAddress.Loopback值而不是解析字符串，并且通常只是在这里和那里简化和清理代码。此外，我目前还没有使用C＃6编译器，因此我更改了使用C＃6功能的代码，以便使用C＃5进行编译。
要做一个完整的聊天服务器，你仍然可以为你做好工作。但我希望上述内容能让你重回正轨。