多客户端服务器 - 客户端断开连接后接收事件变得疯狂异步错误

时间:2012-10-28 13:42:51

标签: c# sockets asynchronous connection client

修改

40多个观点,只有一个能够提供帮助,这个问题不值得投票吗? ;)

/编辑

我再次提到c#中的套接字编程问题。

我已经设置了一个带有自制控制台(richTextBox)的小服务器,它正在监听多个连接。

一切正常,但如果我关闭其中一个连接的客户端,程序将给我一个异步错误,并在控制台上不断从客户端写入一条空白消息(事件:ClientReceivedHandler)

所以有人可以帮我找到问题吗?

我的代码:

SERVER - Form1.cs:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Net.Sockets;


namespace GameServer {
public partial class Form1 : Form {

    // ### MAIN
    public bool serverRunning = false;
    public int serverListenPort = 6666;

    static Listener l;

    public Form1() {
        InitializeComponent();

        l = new Listener( serverListenPort );
        l.SocketAccepted += new Listener.SocketAcceptedHandler( l_SocketAccepted );
    }

    void l_SocketAccepted( Socket e ) {
        Client client = new Client( e );
        client.Received += new Client.ClientReceivedHandler( client_Received );
        client.Disconnected += new Client.ClientDisconnectedHandler( client_Disconnected );

        Invoke( ( MethodInvoker )delegate {
            dataGridViewConnections.Rows.Add( client.ID, client.EndPoint.ToString() );
            consoleWrite( DateTime.Now + " - " + client.EndPoint + " connected to server.\n\n", Color.Lime );
        } );
    }

    void client_Received( Client sender, byte[] data ) {
        Invoke( ( MethodInvoker )delegate {
            consoleWrite( DateTime.Now + "-" + sender.EndPoint + " :\n" + Encoding.Default.GetString( data ) + "\n\n", Color.White );;
        } );
    }

    void client_Disconnected( Client sender ) {
        Invoke( ( MethodInvoker )delegate {
            for( int i = 0; i < dataGridViewConnections.Rows.Count; i++ ) {
                if( dataGridViewConnections.Rows[i].Cells[0].Value.ToString() == sender.ID.ToString() ) {
                    dataGridViewConnections.Rows.RemoveAt( i );
                    consoleWrite( DateTime.Now + " - " + sender.EndPoint + " disconnected from server.\n\n", Color.OrangeRed );
                    break;
                }
            }
        } );
    }

    private void checkBox1_Click(object sender, EventArgs e) {
        checkBox1.Enabled = false;
        if( !serverRunning ) {
            consoleWrite( DateTime.Now + " " + markerSystem + "start\n", Color.White );
            ServerStart();
            checkBox1.Text = "Stop";
        } else {
            consoleWrite( DateTime.Now + " " + markerSystem + "stop\n", Color.White );
            ServerStop();
            checkBox1.Text = "Start";
        }
        checkBox1.Enabled = true;
    }

    private void ServerStart() {
        if( !serverRunning ) {
            consoleWrite( "* Starting server . . .\n", Color.Orange );
            // Start Server
            l.Start();
            serverRunning = true;
            consoleWrite( "* Server started !\n", Color.Lime );
            consoleWrite("Listening on port " + serverListenPort + ".\n\n", Color.White );
        } else {
            consoleWrite( "* ERROR: Server already started !\n\n", Color.Red );
        }
    }

    private void ServerStop() {
        if( serverRunning ) {
            consoleWrite( "* Stopping server . . .\n", Color.Orange );
            // Stop Server
            l.Stop();
            serverRunning = false;
            consoleWrite( "* Server stopped !\n\n", Color.Lime );
        } else {
            consoleWrite( "* ERROR: Server already stopped !\n\n", Color.Red );
        }
    }

    private string markerSystem = "@System -> ";
    private string marker = "-> ";

    private void consoleWrite( string text, Color color ) {
        consoleText.SelectionStart = consoleText.Text.Length;
        consoleText.SelectionLength = 0;
        consoleText.SelectionColor = color;
        consoleText.AppendText( text );
    }
}
}

SERVER - Listener.cs:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Net;
using System.Net.Sockets;

namespace GameServer {
    class Listener {
        Socket s;

        public bool Listening {
            get;
            private set;
        }

        public int Port {
            get;
            private set;
        }

        public  Listener( int port ) {
            Port = port;
            s = new Socket( AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp );
        }

        public void Start() {
            if( Listening ) {
                return;
            }

            s.Bind( new IPEndPoint( 0, Port ) );
            s.Listen(0);

            s.BeginAccept( callback, null );
            Listening = true;
        }

        public void Stop() {
            if( !Listening ) {
                return;
            }

            s.Close();
            s.Dispose();
            s = new Socket( AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp );
        }

        void callback( IAsyncResult ar ) {
            try {
                Socket s = this.s.EndAccept( ar );

                if( SocketAccepted != null ) {
                    SocketAccepted( s );
                }

                this.s.BeginAccept( callback, null );
            } catch( Exception ex ) {
                MessageBox.Show( ex.Message );
            }
        }

        public delegate void SocketAcceptedHandler( Socket e );
        public event SocketAcceptedHandler SocketAccepted;
    }
}

SERVER - Client.cs:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Net;
using System.Net.Sockets;

namespace GameServer {
    class Client {
        public string ID {
            get;
            private set;
        }

        public IPEndPoint EndPoint {
            get;
            private set;
        }

        Socket sck;

        public Client( Socket accepted ) {
            sck = accepted;
            ID = Guid.NewGuid().ToString();
            EndPoint = ( IPEndPoint )sck.RemoteEndPoint;
            sck.BeginReceive( new byte[] { 0 }, 0, 0, 0, callback, null );
        }

        void callback( IAsyncResult ar ) {
            try {
                sck.EndReceive( ar );

                byte[] buf = new byte[8192];
                int rec = sck.Receive( buf, buf.Length, 0 );

                if( rec < buf.Length ) {
                    Array.Resize<byte>( ref buf, rec );
                }

                if( Received != null ) {
                    Received( this, buf );
                }

                sck.BeginReceive( new byte[] { 0 }, 0, 0, 0, callback, null );
            } catch( Exception ex ) {
                MessageBox.Show( ex.Message );
                Close();

                if( Disconnected != null ) {
                    Disconnected( this );
                }
            }
        }

        public void Close() {
            sck.Close();
            sck.Dispose();
        }

        public delegate void ClientReceivedHandler( Client sender, byte[] data );
        public delegate void ClientDisconnectedHandler( Client sender );

        public event ClientReceivedHandler Received;
        public event ClientDisconnectedHandler Disconnected;
    }
}

客户 - Form1.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Net;
using System.Net.Sockets;

namespace GameClient {
    public partial class Form1:Form {
        Socket sck;

        public Form1() {
            InitializeComponent();

            sck = new Socket( AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp );
            sck.Connect( "127.0.0.1", 6666 );
        }

        private void button1_Click( object sender, EventArgs e ) {
            int s = sck.Send( Encoding.Default.GetBytes( textBox1.Text ) );

            if( s > 0 ) {
                textBox1.Text = "";
            }
        }

        private void button2_Click( object sender, EventArgs e ) {
            sck.Close();
            sck.Dispose();
        }
    }
}

我真的很高兴让这台服务器稳定,所以我可以开始实现多人游戏服务器逻辑:D

感谢所有能帮助我的人。

P.S。如果有人需要查看问题,我可以上传VS项目文件或服务器和客户端的.exe文件。

更新:

第一个问题(异步错误)出现在try-catch的Listener.cs文件中。 catch部分中的messagebox给出了这个文本:

“IAsyncResult对象未从相应的异步方法返回。参数:asyncResult”

这是在调用“ServerStop()”方法时出现的。

第二个问题是SERVER-Form1.cs中client_Received()方法中的任何位置。

它似乎不断接收空白数据,因此它在console / richTextBox中输出一条空白消息

我不熟悉c#中的socket-logic,所以我无法弄清楚locig-error发生在代码中的哪个位置。

希望有人找到它。

编辑:

zip文件中的项目文件 http://ace-acid.no-ip.org/GameServer/

(c)中

1 个答案:

答案 0 :(得分:1)

  

第一个问题(异步错误)出现在try-catch的Listener.cs文件中。 catch部分中的messagebox给出了这个文本:

     
    

“未从相应的对象返回IAsyncResult对象     异步方法。参数:asyncResult“

  

Listener.cs - GameServer 中,可以安全地忽略此错误。我相信忽略错误不会在启动/停止套接字期间引起问题。问题是您忘记在Listening = false;的末尾添加Stop(),以便应用程序可以再次调用Start()来启动套接字。否则,如果停止,套接字将永远不会启动。

示例

public void Stop()
{
     if (!Listening)
     {
          return;
     }

     s.Close();
     s = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
     Listening = false; //Set Listening to False to start the socket again
}

虽然设置Listening = false;将解决重新启动套接字的问题,但它不会阻止您获得上面提到的异常,因为该异常不依赖于Listening

我已经尝试修复此问题,但它总是告诉我无法访问已处置的对象s(socket),因此我认为异常基于此行s = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

无论如何都可以安全地忽略异常,我忽略了它并且它完美地工作了。要忽略它,只需创建一个获取异常的try/catch块,如果异常消息包含asyncResult,则忽略弹出带有异常的框。

示例

void callback(IAsyncResult ar)
{

      try
      {

           Socket s = this.s.EndAccept(ar);
           if (SocketAccepted != null)
           {
                SocketAccepted(s);
           }
           this.s.BeginAccept(callback, null);
      }
      catch (Exception ex)
      {
           if (!ex.Message.Contains("asyncResult")) //Proceed only if the exception does not contain asyncResult
           {
                MessageBox.Show(ex.Message);
           }
      }
}
  

它似乎不断接收空白数据,因此它在console / richTextBox中输出一条空白消息

是的,由于存在连接,它将始终收到空白数据。您可以在以下屏幕截图中看到这一点

Blank data sent from Picrofo Console

要解决此问题,您首先需要检查Encoding中使用byte[] data的返回字符串是否为空。然后,您可以在console / richtextbox中编写一个新行

示例

Form1.cs - GameServer

使用以下代码替换client_Received(Client sender, byte[] data)

void client_Received(Client sender, byte[] data)
{
     if (Encoding.Default.GetString(data) != "") //Proceed only if data is not blank
     {
          Invoke((MethodInvoker)delegate
          {
               consoleWrite(DateTime.Now + "-" + sender.EndPoint + " :\n" + Encoding.Default.GetString(data) + "\n\n", Color.White); ;
            });
          }
     }
}

应用修复后,这是输出

No more blank data!

还有一个问题,您可能忘记提及,在Connections选项卡下,即使服务器断开连接,列表也永远不会被清除。只需拨打dataGridViewConnections.Rows.Clear();即可在调用ServerStop()时清除连接列表。

示例

在Form1.cs中 - GameServer

使用以下代码替换ServerStop()

private void ServerStop()
{
     if (serverRunning)
     {
          consoleWrite("* Stopping server . . .\n", Color.Orange);
          l.Stop();
          serverRunning = false;
          consoleWrite("* Server stopped !\n\n", Color.Lime);
          dataGridViewConnections.Rows.Clear(); // Clear connections

     }
     else
     {
          consoleWrite("* ERROR: Server already stopped !\n\n", Color.Red);
     }
 }

这就是我现在所能发现的全部内容,如果我发现任何相关内容,我会及时通知你。

或者,您可以找到属于命名空间的项目文件GameServer here

谢谢, 我希望你觉得这很有帮助:)