.NET 3.x Clients-Server Socket - C#

Узнай цену своей работы

Формулировка задачи:

Доброго времени суток. Сижу пишу дипломную работу по роботе с Socket, но проблема в том то я не когда с ними не работал, у меня на данный момент реализовано полною работу со стороны клиента к серверу, то есть передача сообщений и приём их на сервере. Но сейчас у меня возникли кое-какие вопросы: 1) Мне надо реализовать передачу данных от сервера до клиента вот весь мой код: 
using System;
using System.IO;
using System.Net;
using System.Net.Sockets;
 
namespace MachineEmulatorServer
{
    internal enum Commands
    {
        Command = 0,
        DbDataRecord = 1
    }
 
    struct ReceiveBuffer
    {
        private const int bufferSize = 1024;
        public byte[] buffer;
        public int toReceive;
        public readonly MemoryStream bufStream;
 
        public ReceiveBuffer(int toRec)
        {
            buffer = new byte[bufferSize];
            toReceive = toRec;
            bufStream = new MemoryStream(toRec);
        }
 
        public void Dispose()
        {
            buffer = null;
            toReceive = 0;
            Close();
            if (bufStream != null)
                bufStream.Dispose();
        }
 
        private void Close()
        {
            if (bufStream != null && bufStream.CanWrite)
                bufStream.Close();
        }
    }
 
    class Client
    {
        private byte[] lenBuffer;
        private ReceiveBuffer buffer;
        private Socket socket;
 
        public IPEndPoint EndPoint
        {
            get
            {
                if (socket != null && socket.Connected)
                    return (IPEndPoint)socket.RemoteEndPoint;
                return new IPEndPoint(IPAddress.None, 0);
            }
        }
 
        public delegate void DisconectedEventHandler(Client sender);
 
        public delegate void DataReceivedHandler(Client sender, ReceiveBuffer e);
 
        public delegate void DataSendHandler(Client sender, int send);
 
        public event DisconectedEventHandler Discotected;
        public event DataReceivedHandler DataReceived;
        public event DataSendHandler OnSend;
 
        public Client(Socket s)
        {
            socket = s;
            lenBuffer = new byte[4];
        }
 
        public void Send(byte[] data, int index, int length)
        {
            socket.BeginSend(BitConverter.GetBytes(length), 0, 4, SocketFlags.None, SendCallBack, null);
            socket.BeginSend(data, index, length, SocketFlags.None, SendCallBack, null);
        }
 
        private void SendCallBack(IAsyncResult ar)
        {
            try
            {
                var send = socket.EndSend(ar);
 
                if (OnSend != null)
                {
                    OnSend(this, send);
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine("Send error\n {0}", ex.Message);
            }
        }
 
        public void Close()
        {
            if (socket != null)
            {
                socket.Disconnect(false);
                socket.Close();
            }
 
            buffer.Dispose();
            socket = null;
            lenBuffer = null;
            Discotected = null;
            DataReceived = null;
        }
 
        public void ReceiveAsync()
        {
            socket.BeginReceive(lenBuffer, 0, lenBuffer.Length, SocketFlags.None, ReceiveCallBack, null);
        }
 
        private void ReceiveCallBack(IAsyncResult ar)
        {
            try
            {
                var rec = socket.EndReceive(ar);
 
                if (rec == 0)
                {
                    if (Discotected != null)
                    {
                        Discotected(this);
                        return;
                    }
                    if (rec != 4)
                    {
                        throw new Exception();
                    }
                }
            }
            catch (SocketException se)
            {
                switch (se.SocketErrorCode)
                {
                    case SocketError.ConnectionAborted:
                    case SocketError.ConnectionReset:
                        if (Discotected != null)
                        {
                            Discotected(this);
                            return;
                        }
                        break;
                }
            }
            catch (ObjectDisposedException)
            {
                return;
            }
            catch (NullReferenceException)
            {
                return;
            }
            catch (Exception ex)
            {
                Console.Write(ex.Message);
                return;
            }
 
            buffer = new ReceiveBuffer(BitConverter.ToInt32(lenBuffer, 0));
 
            socket.BeginReceive(buffer.buffer, 0, buffer.buffer.Length, SocketFlags.None, ReceivePacketCallBack, null);
        }
 
        void ReceivePacketCallBack(IAsyncResult ar)
        {
            var rec = socket.EndReceive(ar);
 
            if (rec <= 0)
                return;
 
            buffer.bufStream.Write(buffer.buffer, 0, rec);
 
            buffer.toReceive -= rec;
 
            if (buffer.toReceive > 0)
            {
                Array.Clear(buffer.buffer, 0, buffer.buffer.Length);
 
                socket.BeginReceive(buffer.buffer, 0, buffer.buffer.Length, SocketFlags.None, ReceivePacketCallBack,
                                    null);
                return;
            }
 
            if (DataReceived != null)
            {
                buffer.bufStream.Position = 0;
                DataReceived(this, buffer);
            }
 
            buffer.Dispose();
 
            ReceiveAsync();
        }
    }
}
using System;
using System.Net;
using System.Net.Sockets;
 
namespace MachineEmulatorServer
{
    class Listener
    {
        public delegate void SocketAcceptedHandler(Socket e);
 
        public event SocketAcceptedHandler Accepted;
 
        private Socket listener;
 
        public bool Running { get; private set; }
 
        public void Start(int port)
        {
            if (Running)
                return;
            listener = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            listener.Bind(new IPEndPoint(0, port));
            listener.Listen(0);
 
            listener.BeginAccept(AcceptedCallBack, null);
            Running = true;
        }
 
        public void Stop()
        {
            if (!Running)
                return;
            listener.Close();
            Running = false;
        }
 
        private void AcceptedCallBack(IAsyncResult ar)
        {
            try
            {
                var s = listener.EndAccept(ar);
 
                if (Accepted != null)
                {
                    Accepted(s);
                }
            }
            catch (Exception e)
            {
            }
 
            if (!Running)
                return;
            try
            {
                listener.BeginAccept(AcceptedCallBack, null);
            }
            catch (Exception)
            {
            }
        }
    }
}
using System.Collections.Generic;
using System.IO;
using System.Windows.Forms;
 
namespace MachineEmulatorServer
{
    public partial class Form1 : Form
    {
        private Listener listener;
        private readonly List<Client> clients;
 
        public Form1()
        {
            InitializeComponent();
            FormClosing += Form1_FormClosing;
            clients = new List<Client>();
        }
 
        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            while (clients.Count != 0)
            {
                clients[0].Close();
                clients.Remove(clients[0]);
            }
 
            if (listener != null && listener.Running)
                listener.Stop();
        }
 
        private void Form1_Load(object sender, System.EventArgs e)
        {
            listener = new Listener();
            listener.Accepted += listener_Accepted;
            listener.Start(5053);
        }
 
        private void listener_Accepted(System.Net.Sockets.Socket e)
        {
            var newClient = new Client(e);
            newClient.DataReceived += client_DataReceived;
            newClient.Discotected += client_Discotected;
            newClient.OnSend += newClient_OnSend;
            newClient.ReceiveAsync();
            SendText("You connected", newClient);
            if (clients == null)
                return;
            clients.Add(newClient);
 
            Invoke((MethodInvoker) delegate
                {
                    TextLogger.Text += "Connected:" + newClient.EndPoint + "\n";
                });
        }
 
        private static void SendText(string text, Client client)
        {
            var bw = new BinaryWriter(new MemoryStream());
            bw.Write((int)Commands.Command);
            bw.Write(text);
            bw.Close();
            var data = ((MemoryStream)bw.BaseStream).ToArray();
            bw.BaseStream.Dispose();
            client.Send(data, 0, data.Length);
        }
 
        void newClient_OnSend(Client sender, int send)
        {
            TextLogger.Text += "Send to: " + sender.EndPoint + "\n";
        }
 
        private void client_Discotected(Client sender)
        {
            for (var i = 0; i < clients.Count; i++)
            {
                if (!Equals(clients[i].EndPoint, sender.EndPoint))
                    continue;
                Invoke((MethodInvoker) delegate
                    {
                        TextLogger.Text += "Disconnected: " + clients[i].EndPoint + "\n";
                    });
                clients[i].Close();
                clients.Remove(clients[i]);
                break;
            }
        }
 
        private void client_DataReceived(Client sender, ReceiveBuffer e)
        {
            var r = new BinaryReader(e.bufStream);
 
            var header = (Commands) r.ReadInt32();
 
            switch (header)
            {
                case Commands.Command:
                    {
                        var s = r.ReadString();
                        Invoke((MethodInvoker) (() => TextLogger.Text += s + "\n"));
                    }
                    break;
                case Commands.DbDataRecord:
                    {
                        var imageBytesLen = r.ReadInt32();
 
                        r.ReadBytes(imageBytesLen);
                        r.ReadString();
                        Invoke((MethodInvoker) delegate
                            {
                                //pbImage.Image = Image.FromStream(new MemoryStream(iBytes));
                            });
                    }
                    break;
            }
        }
    }
}
using System;
using System.IO;
using System.Net.Sockets;
 
namespace MachineEmulatorUsers
{
    internal enum Commands
    {
        Command = 0,
        DbDataRecord = 1
    }
 
    struct ReceiveBuffer
    {
        private const int bufferSize = 1024;
        public byte[] buffer;
        public int toReceive;
        public readonly MemoryStream bufStream;
 
        public ReceiveBuffer(int toRec)
        {
            buffer = new byte[bufferSize];
            toReceive = toRec;
            bufStream = new MemoryStream(toRec);
        }
 
        public void Dispose()
        {
            buffer = null;
            toReceive = 0;
            Close();
            if (bufStream != null)
                bufStream.Dispose();
        }
 
        private void Close()
        {
            if (bufStream != null && bufStream.CanWrite)
                bufStream.Close();
        }
    }
 
    internal class Client
    {
        private byte[] lenBuffer;
        private ReceiveBuffer buffer;
        private Socket socket;
 
        public delegate void OnConnectEventHandler(Client sender, bool connected);
 
        public delegate void OnSendEventHandler(Client sender, int send);
 
        public delegate void DataReceivedHandler(Client sender, ReceiveBuffer e);
 
        public delegate void OnDisconnectEventHandler(Client sender);
 
        public event OnConnectEventHandler OnConnect;
        public event OnSendEventHandler OnSend;
        public event OnDisconnectEventHandler OnDisconnect;
        public event DataReceivedHandler DataReceived;
 
        private bool Connected
        {
            get { return socket != null && socket.Connected; }
        }
 
        public Client()
        {
            socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
        }
 
        public void Connect(string ipAddress, int port)
        {
            if (socket == null)
                socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            socket.BeginConnect(ipAddress, port, ConnectCallBack, null);
        }
 
        private void ConnectCallBack(IAsyncResult ar)
        {
            try
            {
                socket.EndConnect(ar);
                if (OnConnect != null)
                {
                    OnConnect(this, Connected);
                }
            }
            catch (Exception)
            {
            }
        }
 
        public void Send(byte[] data, int index, int length)
        {
            if (!Connected)
                return;
            socket.BeginSend(BitConverter.GetBytes(length), 0, 4, SocketFlags.None, SendCallBack, null);
            socket.BeginSend(data, index, length, SocketFlags.None, SendCallBack, null);
        }
 
        private void SendCallBack(IAsyncResult ar)
        {
            try
            {
                var send = socket.EndSend(ar);
 
                if (OnSend != null)
                {
                    OnSend(this, send);
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine("Send error\n {0}", ex.Message);
            }
        }
 
        public void Disconnect()
        {
            try
            {
                if (!socket.Connected) return;
                socket.Close();
                socket = null;
                if (OnDisconnect != null)
                {
                    OnDisconnect(this);
                }
            }
            catch (Exception)
            {
            }
        }
 
        public void ReceiveAsync()
        {
            socket.BeginReceive(lenBuffer, 0, lenBuffer.Length, SocketFlags.None, ReceiveCallBack, null);
        }
 
        private void ReceiveCallBack(IAsyncResult ar)
        {
            try
            {
                var rec = socket.EndReceive(ar);
 
                if (rec == 0)
                {
                    if (rec != 4)
                    {
                        throw new Exception();
                    }
                }
            }
            catch (SocketException se)
            {
                switch (se.SocketErrorCode)
                {
                    case SocketError.ConnectionAborted:
                    case SocketError.ConnectionReset:
                        Disconnect();
                        break;
                }
            }
            catch (ObjectDisposedException)
            {
                return;
            }
            catch (NullReferenceException)
            {
                return;
            }
            catch (Exception ex)
            {
                Console.Write(ex.Message);
                return;
            }
 
            buffer = new ReceiveBuffer(BitConverter.ToInt32(lenBuffer, 0));
 
            socket.BeginReceive(buffer.buffer, 0, buffer.buffer.Length, SocketFlags.None, ReceivePacketCallBack, null);
        }
 
        void ReceivePacketCallBack(IAsyncResult ar)
        {
            var rec = socket.EndReceive(ar);
 
            if (rec <= 0)
                return;
 
            buffer.bufStream.Write(buffer.buffer, 0, rec);
 
            buffer.toReceive -= rec;
 
            if (buffer.toReceive > 0)
            {
                Array.Clear(buffer.buffer, 0, buffer.buffer.Length);
 
                socket.BeginReceive(buffer.buffer, 0, buffer.buffer.Length, SocketFlags.None, ReceivePacketCallBack,
                                    null);
                return;
            }
 
            if (DataReceived != null)
            {
                buffer.bufStream.Position = 0;
                DataReceived(this, buffer);
            }
 
            buffer.Dispose();
 
            ReceiveAsync();
        }
    }
}
using System;
using System.ComponentModel;
using System.Data.Common;
using System.Drawing;
using System.IO;
using System.Threading;
using System.Windows.Forms;
 
namespace MachineEmulatorUsers
{
    public partial class Form1 : Form
    {
        private readonly Client client;
        private bool connect;
        private DbDataRecord dataRecords;
        private BackgroundWorker background;
        private string errorMessage;
 
        public Form1()
        {
            InitializeComponent();
            client = new Client();
            client.OnConnect += client_onConnect;
            client.OnDisconnect += client_onDisconnect;
            client.OnSend += client_onSend;
            FormClosing += Form1_FormClosing;
        }
 
        private void Form1_Load(object sender, EventArgs e)
        {
            client.Connect("127.0.0.1", 5053);
            Thread.Sleep(1500);
            background = new BackgroundWorker
            {
                WorkerReportsProgress = true,
                WorkerSupportsCancellation = true
            };
            background.DoWork += bw_DoWork;
            background.ProgressChanged += bw_ProgressChanged;
            background.RunWorkerCompleted += bw_RunWorkerCompleted;
            if (connect)
            {
                LoadGroupBox.Visible = true;
                client.DataReceived+=Server_DataReceived;
                client.ReceiveAsync();
                return;
            }
            ErrorLabel.Visible = true;
            errorMessage = "Кліент не знайшов з'єднання з Сервером...\nКлієн буде завершено через ";
            background.RunWorkerAsync();
        }
 
        void bw_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            Close();
        }
 
        void bw_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            ErrorLabel.Text = errorMessage + e.ProgressPercentage;
        }

        private static void bw_DoWork(object sender, DoWorkEventArgs e)
        {
            var worker = sender as BackgroundWorker;
 
            for (var i = 10; i > 0; i--)
            {
                if (worker != null && worker.CancellationPending)
                {
                    e.Cancel = true;
                    break;
                }
                Thread.Sleep(500);
                if (worker != null)
                    worker.ReportProgress(i);
            }
        }
 
        void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            if (client != null)
                client.Disconnect();
        }
 
        void client_onSend(Client sender, int send)
        {
            Invoke((MethodInvoker) delegate
                {
                    Text = string.Format("Data sent: {0}", send);
                });
        }
 
        private void client_onConnect(Client sender, bool connected)
        {
            connect = connected;
        }
 
        private void client_onDisconnect(Client sender)
        {
            connect = false;
        }
 
        private void InsertText(object sender, EventArgs e)
        {
            var s = sender as PictureBox;
            if (s != null)
                textBox1.Text += ((PictureBox) sender).Tag;
        }
 
        private void StartButtonClick(object sender, EventArgs e)
        {
            LoadContent();
            LoadGroupBox.Visible = false;
            KeyBoard.Visible = true;
            button1.Visible = true;
            textBox1.Visible = true;
        }
 
        private void button1_Click(object sender, EventArgs e)
        {
            SendText(textBox1.Text);
        }
 
        void SendText(string text)
        {
            var bw = new BinaryWriter(new MemoryStream());
            bw.Write((int)Commands.Command);
            bw.Write(text);
            bw.Close();
            var data = ((MemoryStream) bw.BaseStream).ToArray();
            bw.BaseStream.Dispose();
            client.Send(data, 0, data.Length);
        }
 
        private void Server_DataReceived(Client sender, ReceiveBuffer e)
        {
            var r = new BinaryReader(e.bufStream);
 
            var header = (Commands) r.ReadInt32();
 
            switch (header)
            {
                case Commands.Command:
                    {
                        var s = r.ReadString();
                        Invoke((MethodInvoker) (() => ExecuteCommand(s)));
                    }
                    break;
                case Commands.DbDataRecord:
                    {
                        var s = r.ReadString();
                        Invoke((MethodInvoker)(() => MessageBox.Show(s)));
                    }
                    break;
            }
        }
 
        private void ExecuteCommand(String com)
        {
            if (com != "Disconnected")
                return;
            errorMessage = "Клієнт був відключений сервером...\nКлієн буде завершено через ";
            background.RunWorkerAsync();
        }
    }
}
Вроде-бы все отлично работает, но когда я начинаю писать DataReceived на стороне клиента и Send на стороне сервера, то в клиенте вылетает ошибка со стороны клиента в Client.cs: 
public void ReceiveAsync()
        {
            socket.BeginReceive(lenBuffer, 0, lenBuffer.Length, SocketFlags.None, ReceiveCallBack, null);
            //Exception: NullReferenceException - в экземпляре объекта не указана ссылка на объект.
        }
2 ) Как по сете можно передать записи из базы данных, что-то типа DbDataRecord. Заранее спасибо.
Тема все еще актуальна.

Решение задачи: «.NET 3.x Clients-Server Socket»

textual
Листинг программы 
private void BackgroundReconnectDoWork(object sender, DoWorkEventArgs e)
        {
            var worker = sender as BackgroundWorker;
            var flag = false;
            while (flag != true)
            {
                Invoke((MethodInvoker) (delegate
                    {
                        client = new Client();
                        client.Connect(adress, port);
                        Thread.Sleep(375);
                        flag = connect;
                    }));
                for (var i = 9; i >= 0; i--)
                {
                    if (worker != null && worker.CancellationPending)
                    {
                        e.Cancel = true;
                        break;
                    }
                    Thread.Sleep(500);
                    if (worker != null)
                        worker.ReportProgress(i);
                }
            }
        }

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Оцени полезность:

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