接收多个不同的消息TcpListener C＃

Question

大家好，我一直在尝试学习如何使用TcpListener和套接字在客户端服务器之间发送一些简单的文本消息。 我已经阅读了许多线程，这些线程似乎在显示如何读取_Buffer，让我们说一个循环以确保读取整个消息。 但是，我似乎无法弄清楚在收到第一个消息后如何获取第二个消息。 我可以很好地连接到服务器，并且可以得到第一条消息。 但是，如果我再次点击客户端上的发送按钮，则不会有任何消息发送到服务器。 这是我的代码：

// SERVER APPLICATION: -----------------------------------------------


namespace TCP_Server
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

    private void btnStartServer_Click(object sender, EventArgs e)
    {
        // Define the TCP Listner:
        TcpListener _listner = new TcpListener(IPAddress.Parse("127.0.0.1"), 7777);

        // Start The Listner:
        _listner.Start();

        //Show the server is now listening:
        listStatus.Items.Add("Server started - Listening on port 7777");

        //Create a socket to accept - This is a Blocking Call:
        Socket _sock = _listner.AcceptSocket();

        //When Client Connects show server has accepted the socket:
        listStatus.Items.Add("User from IP " + _sock.RemoteEndPoint);

        while (_sock.Connected)
        {

            // Create Byte to Receive Data:
            byte[] _Buffer = new byte[1024];

            // Create integer to hold how large the Data Received is:
            int _DataReceived = _sock.Receive(_Buffer);

            // Lets Server Know Message is Received:
            listStatus.Items.Add("Message Received...");

            // Convert Buffer to a String:
            string _Message = Encoding.ASCII.GetString(_Buffer);

            // Post Message to the Server Window:
            listStatus.Items.Add(_Message);

            _sock.Close();
        }
    }
}


}


 // CLIENT APPLICATION: ----------------------------------------------------

namespace TCP__Client { public partial class Form1 : Form { public Form1() { InitializeComponent(); }

    // Defind the TCP Client:
    TcpClient _Client = new TcpClient();

    private void btnConnect_Click(object sender, EventArgs e)
    {
        // Connect the TCP Client:
        _Client.Connect("127.0.0.1", 7777);

        // Show the Client has Connected:
        listStatus.Items.Add("Connected to Server 127.0.0.1");
    }

    private void btnSend_Click(object sender, EventArgs e)
    {
        while (_Client.Connected)
        {
            // Create a Stream:                
            Stream _Stream = _Client.GetStream();

            // Create Instance of an Encoder:
            ASCIIEncoding _Asc = new ASCIIEncoding();

            byte[] _Buffer = new byte[1024];

            // Create Buffer to Send Message:
            _Buffer = _Asc.GetBytes(txtMessage.Text);

            // Show Client is Sending Message:
            listStatus.Items.Add("Tranmitting Message...");

            // Write Message to the Stream:
            _Stream.Write(_Buffer, 0, _Buffer.Length);

            // Close Stream
            _Stream.Close();
            _Stream.Dispose();
        }
    }
}

}

如果有人可以解释如何做到这一点，我将不胜感激，我将不胜感激。 我在使用任务和线程方面确实有一点经验，这是我需要做的事情吗？ 我只是想对此有所了解，所以我可以开始学习它。 如果有人有任何建议或示例对您有帮助，请分享。

Answer 1

当客户端仍连接到服务器时，请不要故意关闭服务器应用程序上的套接字。 由于您必须保持活动状态才能接收其他消息，因此请重复接收函数调用。 如果没有从客户端发送的数据，则Receive（）函数调用将自动阻止当前线程等待可用数据。 如果再次单击客户端应用程序上的“发送消息”，则数据将可用于服务器，并将取消阻止服务器应用程序上的该阻止部分。

您的服务器应用程序可能会在AcceptSocket（）和Receive（）部分上阻止UI线程。 单击StartServer按钮时，由于没有可用的传入连接，您的服务器窗口（UI）可能没有响应，并且您在listStatus控件上看不到消息。 因此，最好将这些Socket代码片段放在单独的线程上运行，以免阻塞UI线程。 要从单独的线程处理UI组件，需要执行线程安全的UI操作。

这是我所做的更改：

服务器

namespace Tcp_Server
{
    public partial class Form1 : Form
    {
        delegate void AddTextCallback(string text);

        public Form1()
        {
            InitializeComponent();
        }

        private void btnStartServer_Click(object sender, EventArgs e)
        {
            ThreadPool.QueueUserWorkItem(new WaitCallback(ServerHandler));
        }

        private void ServerHandler(object args)
        {
            TcpListener _listner = new TcpListener(IPAddress.Parse("127.0.0.1"), 7777);

            // Start The Listner:
            _listner.Start();

            //Show the server is now listening (Note: UI Thread-Safe is required):
            AddText("Server started - Listening on port 7777");

            //Create a socket to accept - This is a Blocking Call:
            Socket _sock = _listner.AcceptSocket();

            //When Client Connects show server has accepted the socket:
            AddText("User from IP " + _sock.RemoteEndPoint);

            while (_sock.Connected)
            {

                // Create Byte to Receive Data:
                byte[] _Buffer = new byte[1024];

                // Create integer to hold how large the Data Received is:
                int _DataReceived = _sock.Receive(_Buffer);

                if (_DataReceived == 0)
                {
                    // Socket has been shutdown by the client.
                    break;
                }

                // Lets Server Know Message is Received:
                AddText("Message Received...");

                // Convert Buffer to a String:
                string _Message = Encoding.ASCII.GetString(_Buffer);

                // Post Message to the Server Window:
                AddText(_Message);
            }

            _sock.Close();
            //When Client disconnect from the server:
            AddText("Client Disconnected.");

            _listner.Stop();
            AddText("Server Stop.");
        }


        private void AddText(string text)
        {
            // InvokeRequired required compares the thread ID of the 
            // calling thread to the thread ID of the creating thread. 
            // If these threads are different, it returns true. 
            if (this.listStatus.InvokeRequired)
            {
                AddTextCallback d = new AddTextCallback(AddText);
                this.Invoke(d, new object[] { text });
            }
            else
            {
                this.listStatus.Items.Add(text);
            }
        }
    }
}

客户

namespace Tcp_Client
{
    public partial class Form1 : Form
    {
        // Defind the TCP Client:
        TcpClient _Client = null;
        Stream _Stream = null;

        public Form1()
        {
            InitializeComponent();
        }

        private void btnConnect_Click(object sender, EventArgs e)
        {
            _Client = new TcpClient();

            // Connect the TCP Client:
            _Client.Connect("127.0.0.1", 7777);

            // Show the Client has Connected:
            listStatus.Items.Add("Connected to Server 127.0.0.1");

            // Create a Stream:                
            _Stream = _Client.GetStream();
        }

        private void btnSend_Click(object sender, EventArgs e)
        {
            if (_Client.Connected)
            {
                // Create Instance of an Encoder:
                ASCIIEncoding _Asc = new ASCIIEncoding();

                byte[] _Buffer = new byte[1024];

                // Create Buffer to Send Message:
                _Buffer = _Asc.GetBytes(txtMessage.Text);

                // Show Client is Sending Message:
                listStatus.Items.Add("Tranmitting Message...");

                // Write Message to the Stream:
                _Stream.Write(_Buffer, 0, _Buffer.Length);
            }
        }

        private void btnDisconnect_Click(object sender, EventArgs e)
        {
            _Stream.Close();
            _Stream.Dispose();
            _Client.Close();
            listStatus.Items.Add("Disconnected from server.");
        }
    }
}