using System.Net.Sockets;
using System.Net;
using System.Text;

namespace WinFormsApp3
{
    public partial class Form1 : Form
    {
        private TcpListener server;
        private List<TcpClient> clients = new List<TcpClient>();

        public Form1()
        {
            InitializeComponent();
        }

        // 啟動服務(wù)端監(jiān)聽
        private async void btnStart_Click(object sender, EventArgs e)
        {
            server = new TcpListener(IPAddress.Any, int.Parse(tbServerIP.Text));
            server.Start();
            UpdateUI("服務(wù)端已啟動...");
            _ = AcceptClientsAsync(); // 啟動異步接受連接

            // 打開客戶端測試窗體（僅用于演示）
            Form2 form2 = new Form2();
            form2.ShowDialog();
        }

        // 異步接受客戶端連接
        private async Task AcceptClientsAsync()
        {
            while (true)
            {
                TcpClient client = await server.AcceptTcpClientAsync();
                clients.Add(client);
                UpdateUI($"客戶端已連接：{client.Client.RemoteEndPoint}");
                _ = HandleClientAsync(client); // 為每個客戶端啟動獨(dú)立處理任務(wù)
            }
        }

        // 處理單個客戶端通信
        private async Task HandleClientAsync(TcpClient client)
        {
            NetworkStream stream = client.GetStream();
            byte[] buffer = new byte[1024];

            try
            {
                while (true)
                {
                    int bytesRead = await stream.ReadAsync(buffer, 0, buffer.Length);
                    if (bytesRead == 0) break; // 客戶端斷開

                    string message = Encoding.UTF8.GetString(buffer, 0, bytesRead);
                    UpdateUI($"接收：{message}");

                    // 廣播消息給所有已連接客戶端
                    foreach (var c in clients.Where(c => c.Connected))
                    {
                        await c.GetStream().WriteAsync(buffer, 0, bytesRead);
                    }
                }
            }
            catch (Exception ex)
            {
                UpdateUI($"客戶端異常斷開：{ex.Message}");
            }
            finally
            {
                clients.Remove(client);
                client.Close();
                UpdateUI("客戶端已斷開連接");
            }
        }

        // 線程安全地更新UI
        private void UpdateUI(string message)
        {
            if (InvokeRequired)
            {
                Invoke(new Action(() => UpdateUI(message)));
                return;
            }
            txtLog.AppendText($"{DateTime.Now:yyyy-MM-dd HH:mm:ss}: {message}\r\n");
        }

        // 窗體關(guān)閉時釋放資源
        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            server?.Stop();
            foreach (var client in clients)
            {
                client?.Close();
            }
            clients.Clear();
        }
    }
}

using System.Net.Sockets;
using System.Text;

namespace WinFormsApp3
{
    public partial class Form2 : Form
    {
        private TcpClient client;
        private NetworkStream stream;

        public Form2()
        {
            InitializeComponent();
        }

        // 連接服務(wù)端
        private async void btnConnect_Click(object sender, EventArgs e)
        {
            try
            {
                client = new TcpClient();
                await client.ConnectAsync(tbServerIP.Text, int.Parse(tbServerPor.Text));
                stream = client.GetStream();
                UpdateUI("已成功連接到服務(wù)端");
                _ = ReceiveDataAsync(); // 啟動異步接收
            }
            catch (Exception ex)
            {
                UpdateUI($"連接失?。簕ex.Message}");
            }
        }

        // 異步接收數(shù)據(jù)
        private async Task ReceiveDataAsync()
        {
            byte[] buffer = new byte[1024];
            try
            {
                while (true)
                {
                    int bytesRead = await stream.ReadAsync(buffer, 0, buffer.Length);
                    if (bytesRead == 0) break;

                    string message = Encoding.UTF8.GetString(buffer, 0, bytesRead);
                    UpdateUI($"接收：{message}");
                }
            }
            catch
            {
                UpdateUI("與服務(wù)端斷開連接");
            }
            finally
            {
                client?.Close();
            }
        }

        // 發(fā)送消息
        private async void btnSend_Click(object sender, EventArgs e)
        {
            if (stream == null || !client.Connected)
            {
                UpdateUI("尚未連接到服務(wù)端");
                return;
            }

            string message = txtMessage.Text;
            byte[] data = Encoding.UTF8.GetBytes(message);
            await stream.WriteAsync(data, 0, data.Length);
            UpdateUI($"發(fā)送：{message}");
            txtMessage.Clear();
        }

        // 線程安全更新UI
        private void UpdateUI(string message)
        {
            if (InvokeRequired)
            {
                Invoke(new Action(() => UpdateUI(message)));
                return;
            }
            txtLog.AppendText($"{DateTime.Now:yyyy-MM-dd HH:mm:ss}: {message}\r\n");
        }

        // 關(guān)閉窗體時清理資源
        private void Form2_FormClosing(object sender, FormClosingEventArgs e)
        {
            client?.Close();
        }
    }
}

private void UpdateUI(string message)
{
    if (InvokeRequired)
    {
        Invoke(new Action(() => UpdateUI(message)));
        return;
    }
    // 安全更新UI
}