C#完整的通信代码(点对点,点对多,同步,异步,UDP,TCP)

来源:互联网 发布:淘宝网页版 编辑:程序博客网 时间:2024/04/29 13:06

C# code
namespace UDPServer
{
    class Program
    {
        static void Main(string[] args)
        {
            int recv;
            byte[] data = new byte[1024];

            //构建TCP 服务器

            //得到本机IP,设置TCP端口号        
            IPEndPoint ipep = new IPEndPoint(IPAddress.Any , 8001);
            Socket newsock = new Socket(AddressFamily.InterNetwork, SocketType.Dgram , ProtocolType.Udp);

            //绑定网络地址
            newsock.Bind(ipep);

            Console.WriteLine("This is a Server, host name is {0}",Dns.GetHostName());

            //等待客户机连接
            Console.WriteLine("Waiting for a client...");

            //得到客户机IP
            IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0);
            EndPoint Remote = (EndPoint)(sender);
            recv = newsock.ReceiveFrom(data, ref Remote);
            Console .WriteLine ("Message received from {0}: ", Remote.ToString ());
            Console .WriteLine (Encoding .ASCII .GetString (data ,0,recv ));

            //客户机连接成功后,发送欢迎信息
            string welcome = "Welcome ! ";

            //字符串与字节数组相互转换
            data  = Encoding .ASCII .GetBytes (welcome );

            //发送信息
            newsock .SendTo (data ,data.Length ,SocketFlags .None ,Remote );
            while (true )
            {
                data =new byte [1024];
                //发送接受信息
                recv =newsock.ReceiveFrom(data ,ref Remote);
                Console .WriteLine (Encoding .ASCII .GetString (data ,0,recv));
                newsock .SendTo (data ,recv ,SocketFlags .None ,Remote );
            }
        }

        }
    }


--------------------------------------------------------------------------------

C# code
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Net.Sockets;

namespace UDPClient
{
    class Program
    {
        static void Main(string[] args)
        {
            byte[] data = new byte[1024];
            string input ,stringData;

            //构建TCP 服务器

            Console.WriteLine("This is a Client, host name is {0}", Dns.GetHostName());

            //设置服务IP,设置TCP端口号
            IPEndPoint ipep = new IPEndPoint(IPAddress .Parse ("127.0.0.1") , 8001);

            //定义网络类型,数据连接类型和网络协议UDP
            Socket server = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);

            string welcome = "Hello! ";
            data = Encoding.ASCII.GetBytes(welcome);
            server.SendTo(data, data.Length, SocketFlags.None, ipep);
            IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0);
            EndPoint Remote = (EndPoint)sender;

            data = new byte[1024];
            int recv = server.ReceiveFrom(data, ref Remote);
            Console.WriteLine("Message received from {0}: ", Remote.ToString());
            Console.WriteLine(Encoding .ASCII .GetString (data,0,recv));
            while (true)
            {
                input = Console .ReadLine ();
                if (input =="exit")
                    break ;
                server .SendTo (Encoding .ASCII .GetBytes (input ),Remote );
                data = new byte [1024];
                recv = server.ReceiveFrom(data, ref Remote);
                stringData = Encoding.ASCII.GetString(data, 0, recv);
                Console.WriteLine(stringData);
            }
            Console .WriteLine ("Stopping Client.");
            server .Close ();
        }

        }
    }

 

--------------------------------------------------------------------------------

C# code

//"开始"按钮事件

  private void button1_Click(object sender, System.EventArgs e) {

   //取得预保存的文件名

   string fileName=textBox3.Text.Trim();

   //远程主机

   string hostName=textBox1.Text.Trim();

   //端口

   int port=Int32.Parse(textBox2.Text.Trim());

   //得到主机信息

   IPHostEntry ipInfo=Dns.GetHostByName(hostName);

   //取得IPAddress[]

   IPAddress[] ipAddr=ipInfo.AddressList;

   //得到ip

   IPAddress ip=ipAddr[0];

   //组合出远程终结点

   IPEndPoint hostEP=new IPEndPoint(ip,port);

   //创建Socket 实例

   Socket socket=new Socket(AddressFamily.InterNetwork,SocketType.Stream,ProtocolType.Tcp);

   try

   {

   //尝试连接

   socket.Connect(hostEP);

   }

   catch(Exception se)

   {

   MessageBox.Show("连接错误"+se.Message,"提示信息

   ,MessageBoxButtons.RetryCancel,MessageBoxIcon.Information);

  }

  //发送给远程主机的请求内容串

  string sendStr="GET / HTTP/1.1/r/nHost: " + hostName +

  "/r/nConnection: Close/r/n/r/n";

   //创建bytes字节数组以转换发送串

   byte[] bytesSendStr=new byte[1024];

   //将发送内容字符串转换成字节byte数组

   bytesSendStr=Encoding.ASCII.GetBytes(sendStr);

  try

  {

  //向主机发送请求

  socket.Send(bytesSendStr,bytesSendStr.Length,0);

  }

  catch(Exception ce)

   {

   MessageBox.Show("发送错误:"+ce.Message,"提示信息

   ,MessageBoxButtons.RetryCancel,MessageBoxIcon.Information);

   }

   //声明接收返回内容的字符串

   string recvStr="";

   //声明字节数组,一次接收数据的长度为1024字节

   byte[] recvBytes=new byte[1024];

   //返回实际接收内容的字节数

   int bytes=0;

  //循环读取,直到接收完所有数据

  while(true)

  {

  bytes=socket.Receive(recvBytes,recvBytes.Length,0);

  //读取完成后退出循环

  if(bytes〈=0)

  break;

  //将读取的字节数转换为字符串

  recvStr+=Encoding.ASCII.GetString(recvBytes,0,bytes);

  }

  //将所读取的字符串转换为字节数组

  byte[] content=Encoding.ASCII.GetBytes(recvStr);

   try

   {

   //创建文件流对象实例

   FileStream fs=new FileStream(fileName,FileMode.OpenOrCreate,FileAccess.ReadWrite);

  //写入文件

  fs.Write(content,0,content.Length);

  }

  catch(Exception fe)

   {

   MessageBox.Show("文件创建/写入错误:"+fe.Message,"提示信息",MessageBoxButtons.RetryCancel,MessageBoxIcon.Information);

   }

   //禁用Socket

   socket.Shutdown(SocketShutdown.Both);

   //关闭Socket

   socket.Close();

   }

   }

 


--------------------------------------------------------------------------------

C# code

TCPClient
TCPClient 类提供了一种使用 TCP 协议连接到某个端点的简化方法。它还通过 NetworkStream 对象展现在连接过程中读取或写入的数据。请参见下面从 QuickStart 文档中摘录的日期/时间客户机示例。

使用 C# 编写
using System;
using System.Net;
using System.Net.Sockets;
using System.IO;
using System.Text;
class Client
{
public static void Main(String[] args)
{
TCPClient tcpc = new TCPClient();
Byte[] read = new Byte[32];
if (args.Length != 1)
{
Console.WriteLine(“请在命令行中指定服务器名称”);
return;
}
String server = args[0];
// 验证服务器是否存在
if (DNS.GetHostByName(server) == null)
{
Console.WriteLine(“找不到服务器:” + 服务器);
return;
}
// 尝试连接到服务器
if (tcpc.Connect(server, 13) == -1)
{
Console.WriteLine(“无法连接到服务器:” + 服务器);
return;
}
// 获取流
Stream s = tcpc.GetStream();
// 读取流并将它转换为 ASCII 码形式
int bytes = s.Read(read, 0, read.Length);
String Time = Encoding.ASCII.GetString(read);
// 显示数据
Console.WriteLine(“已接收到的” + 字节 + “字节”);
Console.WriteLine(“当前日期和时间是:” + 时间);
tcpc.Close();
}
}

TCPListener
TCPListener 类便于在来自某个客户机的 TCP 连接的特定套接字上进行侦听的工作。请参见下面包括在 QuickStart 文档中的日期/时间服务器示例。

使用 C# 编写
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
class Server
{
public static void Main()
{
DateTime now;
String strDateLine;
Encoding ASCII = Encoding.ASCII;
// 在端口 13 进行侦听
TCPListener tcpl = new TCPListener(13);
tcpl.Start();
Console.WriteLine(“正在等待客户进行连接”);
Console.WriteLine(“请按 Ctrl+c 退出...”);
while (true)
{
// 接收会阻塞,直到有人连接上
Socket s = tcpl.Accept();
// 获取当前的日期和时间并将它连接成一个字符串
now = DateTime.Now;
strDateLine = now.ToShortDateString() + " " +
now.ToLongTimeString();
// 将该字符串转换成一个字节数组并发送它
Byte[] byteDateLine =
ASCII.GetBytes(strDateLine.ToCharArray());
s.Send(byteDateLine, byteDateLine.Length, 0);
Console.WriteLine(“发送” + strDateLine);
}
}
}

 

--------------------------------------------------------------------------------

#region "Download: File transfer FROM ftp server"
  /// <summary>
  /// Copy a file from FTP server to local
  /// </summary>
  /// <param name="sourceFilename">Target filename, if required</param>
  /// <param name="localFilename">Full path of the local file</param>
  /// <returns></returns>
  /// <remarks>Target can be blank (use same filename), or just a filename
  /// (assumes current directory) or a full path and filename</remarks>
  public bool Download(string sourceFilename, string localFilename, bool PermitOverwrite)
  {
  //2. determine target file
  FileInfo fi = new FileInfo(localFilename);
  return this.Download(sourceFilename, fi, PermitOverwrite);
  }


  //Version taking an FtpFileInfo
  public bool Download(FtpFileInfo file, string localFilename, bool permitOverwrite)
  {
  return this.Download(file.FullName, localFilename, permitOverwrite);
  }

  //Another version taking FtpFileInfo and FileInfo
  public bool Download(FtpFileInfo file, FileInfo localFI, bool permitOverwrite)
  {
  return this.Download(file.FullName, localFI, permitOverwrite);
  }

  //Version taking string/FileInfo
  public bool Download(string sourceFilename, FileInfo targetFI, bool permitOverwrite)
  {
  //1. check target
  if (targetFI.Exists && !(permitOverwrite))
  {
  throw (new ApplicationException("Target file already exists"));
  }

  //2. check source
  string target;
  if (sourceFilename.Trim() == "")
  {
  throw (new ApplicationException("File not specified"));
  }
  else if (sourceFilename.Contains("/"))
  {
  //treat as a full path
  target = AdjustDir(sourceFilename);
  }
  else
  {
  //treat as filename only, use current directory
  target = CurrentDirectory + sourceFilename;
  }

  string URI = Hostname + target;

  //3. perform copy
  System.Net.FtpWebRequest ftp = GetRequest(URI);

  //Set request to download a file in binary mode
  ftp.Method = System.Net.WebRequestMethods.Ftp.DownloadFile;
  ftp.UseBinary = true;

  //open request and get response stream
  using (FtpWebResponse response = (FtpWebResponse)ftp.GetResponse())
  {
  using (Stream responseStream = response.GetResponseStream())
  {
  //loop to read & write to file
  using (FileStream fs = targetFI.OpenWrite())
  {
  try
  {
  byte[] buffer = new byte[2048];
  int read = 0;
  do
  {
  read = responseStream.Read(buffer, 0, buffer.Length);
  fs.Write(buffer, 0, read);
  } while (!(read == 0));
  responseStream.Close();
  fs.Flush();
  fs.Close();
  }
  catch (Exception)
  {
  //catch error and delete file only partially downloaded
  fs.Close();
  //delete target file as it’s incomplete
  targetFI.Delete();
  throw;
  }
  }

  responseStream.Close();
  }

  response.Close();
  }

  return true;
  }
  #endregion


--------------------------------------------------------------------------------

简单的UDP收发.


发送

C# code

                    try
                    {
                        Socket s = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);  //向此网段发广播包
                          int UDPListenerPort = 8082;
                        IPAddress broadcast = IPAddress.Parse("192.168.0.255"); //此处根据IP及子网掩码改为相应的广播IP
                        string ts = "This is UPD string for sending";
                        byte[] sendbuf = Encoding.ASCII.GetBytes(ts);
                        IPEndPoint ep = new IPEndPoint(broadcast, UDPListenerPort);
                        s.SendTo(sendbuf, ep);

                    }
                    catch (Exception e)
                    {}


接收

C# code

           UdpClient listener;
            int UDPListenerPort = 8082;
            IPEndPoint groupEP = new IPEndPoint(IPAddress.Any, UDPListenerPort);

            try
            {
                while (true)
                {
                    byte[] bytes = listener.Receive(ref groupEP);
                    string RecIP = groupEP.ToString().Substring(0, groupEP.ToString().IndexOf(":"));  //收到发送UPD端的IP
                    string RecStr = Encoding.ASCII.GetString(bytes, 0, bytes.Length);   //收到的UPD字符串
                }
            }
            catch
            {}

 

--------------------------------------------------------------------------------

C# code
TCPClient
TCPClient 类提供了一种使用 TCP 协议连接到某个端点的简化方法。它还通过 NetworkStream 对象展现在连接过程中读取或写入的数据。请参见下面从 QuickStart 文档中摘录的日期/时间客户机示例。


使用 C# 编写
using System;
using System.Net;
using System.Net.Sockets;
using System.IO;
using System.Text;
class Client
{
public static void Main(String[] args)
{
TCPClient tcpc = new T…
[/Quote]


--------------------------------------------------------------------------------

来一个Remoting的:


C# code

using System;

namespace Remotable
{

    public class RemotableType : MarshalByRefObject
    {
        private string _internalString = "This is the RemotableType.";
        public string StringMethod()
        {
            return _internalString;
        }
    }

}

using System;
using System.Runtime.Remoting;

namespace RemotingFirst
{

    public class Listener
    {
        public static void Main()
        {
            RemotingConfiguration.Configure("Listener.exe.config");
            Console.WriteLine("Listening for requests. Press Enter to exit");
            Console.ReadLine();
        }
    }

}

using System;
using System.Runtime.Remoting;

namespace Client
{

    public class Client
    {

        public static void Main()
        {
            RemotingConfiguration.Configure("Client.exe.config");
            Remotable.RemotableType remoteObject = new Remotable.RemotableType();
            Console.WriteLine(remoteObject.StringMethod());
        }
    }

}

Listener.exe.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <system.runtime.remoting>
      <application>
         <service>
            <wellknown
               mode="Singleton"
               type="Remotable.RemotableType, RemotableType"
               objectUri="RemotableType.rem"
            />
         </service>
         <channels>
            <channel ref="http" port="8989"/>
         </channels>
      </application>
    </system.runtime.remoting>
</configuration>

 

 

--------------------------------------------------------------------------------

实只要用到Socket联接,基本上就得使用Thread,是交叉使用的。
C#封装的Socket用法基本上不算很复杂,只是不知道托管之后的Socket有没有其他性能或者安全上的问题。
在C#里面能找到的最底层的操作也就是socket了,概念不做解释。
程序模型如下:
WinForm程序 : 启动端口侦听;监视Socket联接情况;定期关闭不活动的联接;
Listener:处理Socket的Accept函数,侦听新链接,建立新Thread来处理这些联接(Connection)。
Connection:处理具体的每一个联接的会话。


1:WinForm如何启动一个新的线程来启动Listener:
  //start the server
  private void btn_startServer_Click(object sender, EventArgs e)
  {
  //this.btn_startServer.Enabled = false;
  Thread _createServer = new Thread(new ThreadStart(WaitForConnect));
  _createServer.Start();
  }
  //wait all connections
  private void WaitForConnect()
  {
  SocketListener listener = new SocketListener(Convert.ToInt32(this.txt_port.Text));
  listener.StartListening();
  }
因为侦听联接是一个循环等待的函数,所以不可能在WinForm的线程里面直接执行,不然Winform也就是无法继续任何操作了,所以才指定一个新的线程来执行这个函数,启动侦听循环。
这一个新的线程是比较简单的,基本上没有启动的参数,直接指定处理函数就可以了。
2:Listener如何启动循环侦听,并且启动新的带有参数的线程来处理Socket联接会话。
先看如何建立侦听:(StartListening函数)
IPEndPoint localEndPoint = new IPEndPoint(_ipAddress, _port);
  // Create a TCP/IP socket.
  Socket listener = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
  // Bind the socket to the local endpoint and listen for incoming connections.
  try
  {
  listener.Bind(localEndPoint);
  listener.Listen(20);//20 trucks

  // Start listening for connections.
  while (true)
  {
  // here will be suspended while waiting for a new connection.
  Socket connection = listener.Accept();
  Logger.Log("Connect", connection.RemoteEndPoint.ToString());//log it, new connection
  ……
  }
  }……
基本步骤比较简单:
建立本机的IPEndPoint对象,表示以本机为服务器,在指定端口侦听;
然后绑定到一个侦听Socket上;
进入while循环,等待新的联接;
如果有新的联接,那么建立新的socket来对应这个联接的会话。
  值得注意的就是这一句联接代码:listener.Accept()。执行这一句的时候,程序就在这个地方等待,直到有新的联检请求的时候程序才会执行下一句。这是同步执行,当然也可以异步执行。
 
  新的联接Socket建立了(Accept之后),对于这些新的socket该怎么办呢?他们依然是一个循环等待,所以依然需要建立新的Thread给这些Socket去处理会话(接收/发送消息),而这个Thread就要接收参数了。
  Thread本身是不能接收参数的,为了让它可以接收参数,可以采用定义新类,添加参数作为属性的方法来解决。
  因为每一个Socket是一个Connection周期,所以我定义了这么一个类public class Connection。这个类至少有这样一个构造函数public Connection(Socket socket); 之所以这么做,就是为了把Socket参数传给这个Connection对象,然后好让Listener启动这个Thread的时候,Thread可以知道他正在处理哪一个Socket。
  具体处理的方法:(在Listener的StartListening函数,ocket connection = listener.Accept();之后)
  Connection gpsCn = new Connection(connection);
  //each socket will be wait for data. keep the connection.
  Thread thread = new Thread(new ThreadStart(gpsCn.WaitForSendData));
  thread.Name = connection.RemoteEndPoint.ToString();
  thread.Start();
 如此一来,这个新的socket在Accept之后就在新的Thread中运行了。
  3:Connection的会话处理
  建立了新的Connection(也就是socket),远程就可以和这个socket进行会话了,无非就是send和receive。
  现在先看看怎么写的这个线程运行的Connection. WaitForSendData函数
  while (true)
  {
  bytes = new byte[1024];
  string data = "";
  //systm will be waiting the msg of receive envet. like Accept();
  //here will be suspended while waiting for socket income msg.
  int bytesRec = this._connection.Receive(bytes);
  _lastConnectTime = DateTime.Now;
  if (bytesRec == 0)//close envent
  {
  Logger.Log("Close Connection", _connection.RemoteEndPoint.ToString());
  break;
  }
  data += Encoding.ASCII.GetString(bytes, 0, bytesRec);
  //…….handle your data.
  }
可以看到这个处理的基本步骤如下:
  执行Receive函数,接收远程socket发送的信息;
  把信息从字节转换到string;
  处理该信息,然后进入下一个循环,继续等待socket发送新的信息。
值得注意的有几个:
  1:Receive函数。这个函数和Listener的Accept函数类似。在这个地方等待执行,如果没有新的消息,这个函数就不会执行下一句,一直等待。
  2:接收的是字节流,需要转化成字符串
  3:判断远程关闭联接的方式
  4:如果对方的消息非常大,还得循环接收这个data。
4:如何管理这些联接(thread)
通过上边的程序,基本上可以建立一个侦听,并且处理联接会话。但是如何管理这些thread呢?不然大量产生thread可是一个灾难。
管理的方法比较简单,在Listener里面我定义了一个静态的哈希表(static public Hashtable Connections=new Hashtable();),存储Connection实例和它对应的Thread实例。而connection中也加入了一个最后联接时间的定义(private DateTime _lastConnectTime;)。在新链接建立的时候(Listener的Accept()之后)就把Connection实例和Thread实例存到哈希表中;在Connection的Receive的时候修改最后联接时间。这样我们就可以知道该Connection在哪里,并且会话是否活跃。
然后在Winform程序里头可以管理这些会话了,设置设置超时。


--------------------------------------------------------------------------------

在网络环境下,我们最感兴趣的两个命名空间是System.Net和 System.Net.Sockets。System.Net命名空间通常与较高程的操作有关,例如download或upload,试用HTTP和其他协议进行Web请求等等,而System.Net.Sockets命名空间所包含的类通常与较低程的操作有关。如果要直接使用Sockets或者 TCP/IP之类的协议,这个命名空间的类是非常有用的。


  在.Net中,System.Net.Sockets 命名空间为需要严密控制网络访问的开发人员提供了 Windows Sockets (Winsock) 接口的托管实现。System.Net 命名空间中的所有其他网络访问类都建立在该套接字Socket实现之上,如TCPClient、TCPListener 和 UDPClient 类封装有关创建到 Internet 的 TCP 和 UDP 连接的详细信息;NetworkStream类则提供用于网络访问的基础数据流等,常见的许多Internet服务都可以见到Socket的踪影,如 Telnet、Http、Email、Echo等,这些服务尽管通讯协议Protocol的定义不同,但是其基础的传输都是采用的Socket。

  其实,Socket可以象流Stream一样被视为一个数据通道,这个通道架设在应用程序端(客户端)和远程服务器端之间,而后,数据的读取(接收)和写入(发送)均针对这个通道来进行。

  可见,在应用程序端或者服务器端创建了Socket对象之后,就可以使用Send/SentTo方法将数据发送到连接的Socket,或者使用Receive/ReceiveFrom方法接收来自连接Socket的数据。

  针对Socket编程,.NET 框架的 Socket 类是 Winsock32 API 提供的套接字服务的托管代码版本。其中为实现网络编程提供了大量的方法,大多数情况下,Socket 类方法只是将数据封送到它们的本机 Win32 副本中并处理任何必要的安全检查。如果你熟悉Winsock API函数,那么用Socket类编写网络程序会非常容易,当然,如果你不曾接触过,也不会太困难,跟随下面的解说,你会发觉使用Socket类开发 windows 网络应用程序原来有规可寻,它们在大多数情况下遵循大致相同的步骤。

  在使用之前,你需要首先创建Socket对象的实例,这可以通过Socket类的构造方法来实现:

public Socket(AddressFamily addressFamily,SocketType socketType,ProtocolType protocolType);

  其中,addressFamily 参数指定 Socket 使用的寻址方案,socketType 参数指定 Socket 的类型,protocolType 参数指定 Socket 使用的协议。

  下面的示例语句创建一个 Socket,它可用于在基于 TCP/IP 的网络(如 Internet)上通讯。

Socket temp = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

  若要使用 UDP 而不是 TCP,需要更改协议类型,如下面的示例所示:

Socket temp = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);

  一旦创建 Socket,在客户端,你将可以通过Connect方法连接到指定的服务器,并通过Send/SendTo方法向远程服务器发送数据,而后可以通过 Receive/ReceiveFrom从服务端接收数据;而在服务器端,你需要使用Bind方法绑定所指定的接口使Socket与一个本地终结点相联,并通过Listen方法侦听该接口上的请求,当侦听到用户端的连接时,调用Accept完成连接的操作,创建新的Socket以处理传入的连接请求。使用完 Socket 后,记住使用 Shutdown 方法禁用 Socket,并使用 Close 方法关闭 Socket。

  可以看出,以上许多方法包含EndPoint类型的参数,在Internet中,TCP/IP 使用一个网络地址和一个服务端口号来唯一标识设备。网络地址标识网络上的特定设备;端口号标识要连接到的该设备上的特定服务。网络地址和服务端口的组合称为终结点,在 .NET 框架中正是由 EndPoint 类表示这个终结点,它提供表示网络资源或服务的抽象,用以标志网络地址等信息。.Net同时也为每个受支持的地址族定义了 EndPoint 的子代;对于 IP 地址族,该类为 IPEndPoint。IPEndPoint 类包含应用程序连接到主机上的服务所需的主机和端口信息,通过组合服务的主机IP地址和端口号,IPEndPoint 类形成到服务的连接点。

  用到IPEndPoint类的时候就不可避免地涉及到计算机IP地址,System.Net命名空间中有两种类可以得到IP地址实例:

  IPAddress类:IPAddress 类包含计算机在 IP 网络上的地址。其Parse方法可将 IP 地址字符串转换为 IPAddress 实例。下面的语句创建一个 IPAddress 实例:

IPAddress myIP = IPAddress.Parse("192.168.0.1");

  Dns 类:向使用 TCP/IP Internet 服务的应用程序提供域名服务。其Resolve 方法查询 DNS 服务器以将用户友好的域名(如"host.mydomain.com")映射到数字形式的 Internet 地址(如 192.168.0.1)。Resolve方法 返回一个 IPHostEnty 实例,该实例包含所请求名称的地址和别名的列表。大多数情况下,可以使用 AddressList 数组中返回的第一个地址。下面的代码获取一个 IPAddress 实例,该实例包含服务器 host.mydomain.com 的 IP 地址。

IPHostEntry ipHostInfo = Dns.Resolve("host.mydomain.com ");
IPAddress ipAddress = ipHostInfo.AddressList[0];

  你也可以使用GetHostName方法得到IPHostEntry实例:

IPHosntEntry hostInfo=Dns.GetHostByName("host.mydomain.com ")

  在使用以上方法时,你将可能需要处理以下几种异常:

  SocketException异常:访问Socket时操作系统发生错误引发

  ArgumentNullException异常:参数为空引用引发

  ObjectDisposedException异常:Socket已经关闭引发

  在掌握上面得知识后,下面的代码将该服务器主机( host.mydomain.com的 IP 地址与端口号组合,以便为连接创建远程终结点:

IPEndPoint ipe = new IPEndPoint(ipAddress,11000);

  确定了远程设备的地址并选择了用于连接的端口后,应用程序可以尝试建立与远程设备的连接。下面的示例使用现有的 IPEndPoint 实例与远程设备连接,并捕获可能引发的异常:

try
{
temp.Connect(ipe);//尝试连接
}
//处理参数为空引用异常
catch(ArgumentNullException ae)
{
Console.WriteLine("ArgumentNullException : {0}", ae.ToString());
}
//处理操作系统异常
catch(SocketException se)
{
Console.WriteLine("SocketException : {0}", se.ToString());
}

  需要知道的是:Socket 类支持两种基本模式:同步和异步。其区别在于:在同步模式中,对执行网络操作的函数(如 Send 和 Receive)的调用一直等到操作完成后才将控制返回给调用程序。在异步模式中,这些调用立即返回。

综合运用以上阐述的使用Visual C#进行Socket网络程序开发的知识,下面的程序是一个简单的Socket通讯实例,client向server发送一段测试字符串,server接收并显示出来,给予client成功相应。

//client端
using System;
using System.Text;
using System.IO;
using System.Net;
using System.Net.Sockets;
namespace socketsample
{
 class Class1
 {
  static void Main()
  {
   try
   {
    int port = 2000;
    string host = "127.0.0.1";
    IPAddress ip = IPAddress.Parse(host);
    IPEndPoint ipe = new IPEndPoint(ip, port);
    Socket c = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
    c.Connect(ipe);
    string sendStr = "hello!This is a socket test";
    byte[] bs = Encoding.ASCII.GetBytes(sendStr);
    c.Send(bs, bs.Length, 0);
    string recvStr = "";
    byte[] recvBytes = new byte[1024];
    int bytes;
    bytes = c.Receive(recvBytes, recvBytes.Length, 0);
    recvStr += Encoding.ASCII.GetString(recvBytes, 0, bytes);
    Console.WriteLine(recvStr);
    c.Close();
   }
   catch (ArgumentNullException e)
   {
    Console.WriteLine("ArgumentNullException: {0}", e);
   }
   catch (SocketException e)
   {
    Console.WriteLine("SocketException: {0}", e);
   }
   Console.ReadLine();
  }
 }
}
//server端
using System;
using System.Text;
using System.IO;
using System.Net;
using System.Net.Sockets;
namespace Project1
{
 class Class2
 {
  static void Main()
  {
   try
   {
    int port = 2000;
    string host = "127.0.0.1";
    IPAddress ip = IPAddress.Parse(host);
    IPEndPoint ipe = new IPEndPoint(ip, port);
    Socket s = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
    s.Bind(ipe);
    s.Listen(0);
    Socket temp = s.Accept();
    string recvStr = "";
    byte[] recvBytes = new byte[1024];
    int bytes;
    bytes = temp.Receive(recvBytes, recvBytes.Length, 0);
    recvStr += Encoding.ASCII.GetString(recvBytes, 0, bytes);
    Console.WriteLine(recvStr);
    string sendStr = "Ok!Sucess!";
    byte[] bs = Encoding.ASCII.GetBytes(sendStr);
    temp.Send(bs, bs.Length, 0);
    temp.Shutdown(SocketShutdown.Both);
    temp.Close();
    s.Shutdown(SocketShutdown.Both);
    s.Close();
   }
   catch (ArgumentNullException e)
   {
    Console.WriteLine("ArgumentNullException: {0}", e);
   }
   catch (SocketException e)
   {
    Console.WriteLine("SocketException: {0}", e);
   }
   Console.ReadLine();
  }
 }
}

  以上程序在VS Express 2005 .Net2.0环境下测试通过。


--------------------------------------------------------------------------------

C#UDP的多路广播组的发送和接收 
 
下列范例使用 UdpClient,在通讯端口11000传送UDP 资料包至多点传送位址群组 224.268.100.2。它传送命令列上指定的信息字串。  

C# code

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

public class UDPMulticastSender { 

private static IPAddress GroupAddress =
IPAddress.Parse("224.168.100.2");
private static int GroupPort = 11000; 

private static void Send( String message) {
UdpClient sender = new UdpClient();
IPEndPoint groupEP = new IPEndPoint(GroupAddress,GroupPort); 

try {
Console.WriteLine("Sending datagram : {0}", message);
byte[] bytes = Encoding.ASCII.GetBytes(message); 

sender.Send(bytes, bytes.Length, groupEP); 

sender.Close(); 

} catch (Exception e) {
Console.WriteLine(e.ToString());

public static int Main(String[] args) {
Send(args[0]); 

return 0;
}
}
 

下列范例使用 UdpClient,在通讯端口 11000 监听广播到多点传送位址群组 224.168.100.2 的 UDP 资料包。它接收信息字串,并將信息写入主控台 (Console)。  

C# code

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

public class UDPMulticastListener { 

private static readonly IPAddress GroupAddress =
IPAddress.Parse("224.168.100.2");
private const int GroupPort = 11000; 

private static void StartListener() {
bool done = false; 

UdpClient listener = new UdpClient();
IPEndPoint groupEP = new IPEndPoint(GroupAddress,GroupPort); 

try {
listener.JoinMulticastGroup(GroupAddress);
listener.Connect(groupEP); 

while (!done) {
Console.WriteLine("Waiting for broadcast");
byte[] bytes = listener.Receive( ref groupEP); 

Console.WriteLine("Received broadcast from {0} :/n {1}/n",
groupEP.ToString(),
Encoding.ASCII.GetString(bytes,0,bytes.Length));

listener.Close(); 

} catch (Exception e) {
Console.WriteLine(e.ToString());

public static int Main(String[] args) {
StartListener(); 

return 0;
}
}  


--------------------------------------------------------------------------------

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


public class UDPMulticastSender {  

private static IPAddress GroupAddress =  
IPAddress.Parse("224.168.100.2");  
private static int GroupPort = 11000;  

private static void Send( String message) {  
UdpClient sender = new UdpClient();  
IPEndPoint groupEP = new IPEndPoint(GroupAddress,GroupPort);  

try {  
Console.WriteLine("Sending datagram : {0}", message);  
byte[] bytes = Encoding.ASCII.GetBytes(message);  

sender.Send(bytes, bytes.Length, groupEP);  

sender.Close();  

} catch (Exception e) {  
Console.WriteLine(e.ToString());  
}  

}  

public static int Main(String[] args) {  
Send(args[0]);  

return 0;  
}  
}  


--------------------------------------------------------------------------------

C# code

 try
                {
                    UdpClient udp=new UdpClient(new IPEndPoint(ipAddress,startPort+i));
                    udp.Close();
                    unUsedPort=startPort+i;
                    break;
                }
                catch
                {
                }

 

--------------------------------------------------------------------------------

[code=C#][/code]using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Collections;
using System.Collections.Specialized;
using System.Threading;
using System.Net.Sockets;
using System.Net;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;
using System.IO;
namespace 聊天工具服务器
{
  public partial class FormMain : Form
  {
  public FormMain()
  {
  InitializeComponent();
  }


  #region 字段定义

  /// <summary>
  /// 服务器程序使用的端口,默认为8888
  /// </summary>
  private int _port = 8888;

  /// <summary>
  /// 接收数据缓冲区大小2K 
  /// </summary>
  private const int _maxPacket =2 * 1024;
  /// <summary>
  /// 服务器端的监听器
  /// </summary>
  private TcpListener _tcpl = null;

  Thread _receiveThread;

  /// <summary>
  /// 保存所有客户端会话的哈希表
  /// </summary>
  private Hashtable _transmit_tb = new Hashtable();

  /// <summary>
  /// 当前文件路径
  /// </summary>
  string MyPath = null;
  /// <summary>
  /// 用户基本信息表,包括UserName,UserPwd,UserNich,UserImg,ZX,UserIp
  /// </summary>
  DataTable TabUser = new DataTable();
  /// <summary>
  /// 用户消息表,保存用户不在线时的消息
  /// </summary>
  DataTable TabUserMessage = new DataTable();
  #endregion

  /// <summary>
  /// 序列化在线列表,向客户端返回序列化后的字节数组
  /// </summary>
  /// <returns>序列化后的字节数组</returns>
  private byte[] SerializeOnlineList()
  {

  StringCollection onlineList = new StringCollection();
  foreach (object o in _transmit_tb.Keys)
  {
  onlineList.Add(o as string);
  }
  IFormatter format = new BinaryFormatter();
  MemoryStream stream = new MemoryStream();
  format.Serialize(stream, onlineList);
  byte[] ret = stream.ToArray();
  stream.Close();
  return ret;
  }

  /// <summary>
  /// 序列化好友列表,向客户端返回序列化后的datatable
  /// </summary>
  /// <returns>序列化后的字节数组</returns>
  private bool SerializeFriendList(object obj, Socket clientSkt)
  {

  DataTable TabmyFriend = new DataTable();
  TabmyFriend.TableName = obj as string;
  try {
  TabmyFriend.ReadXml(MyPath + "//UserFriend//" + TabmyFriend.TableName + ".xml");
  TabmyFriend.Columns.Add("UserImg", typeof(String));
  TabmyFriend.Columns.Add("UserNich", typeof(String));
  TabmyFriend.Columns.Add("ZX", typeof(Boolean));
  TabmyFriend.Columns.Add("UserIp", typeof(String));
  foreach (DataRow myrow in TabmyFriend.Rows)
  {
  DataRow[] DataRows = TabUser.Select(" UserName = ‘" + myrow["UserName"].ToString() + "’");
  if (DataRows.Length > 0)
  {
  myrow["UserImg"] = DataRows[0]["UserImg"].ToString();
  myrow["UserNich"] = DataRows[0]["UserNich"].ToString();
  try
  {
  myrow["ZX"] = (bool)DataRows[0]["ZX"];
  myrow["UserIp"] = DataRows[0]["UserIp"].ToString();
  }  
  catch
  {
  myrow["ZX"] = false;
  myrow["UserIp"] = "";
  }
   
  }
  }
  }
  catch
  {
  TabmyFriend.Columns.Add("UserName", typeof(String));
  TabmyFriend.Columns.Add("UserImg", typeof(String));
  TabmyFriend.Columns.Add("ZX", typeof(Boolean));
  TabmyFriend.Columns.Add("UserIp", typeof(String));
  }
  IFormatter format = new BinaryFormatter();
  MemoryStream stream = new MemoryStream();
  format.Serialize(stream, TabmyFriend);
  stream.Position = 0;
  byte[] ret = new byte[_maxPacket];
  int count = 0;
  count = stream.Read(ret, 0, _maxPacket);
  //先发送响应信号,用户客户机的判断
  clientSkt.Send(Encoding.Unicode.GetBytes("cmd::RequestFriendList"));
  while (count >0)
  {
  clientSkt.Send(ret);
  count = stream.Read(ret, 0, _maxPacket);
  }
  //发送结束信号
  clientSkt.Send(Encoding.Unicode.GetBytes("Find::RequestFriendListEnd"));  
  stream.Close();
  return true ;
  }

  private void FormMain_Load(object sender, EventArgs e)
  {
  MyPath = Application.StartupPath;
  Read_User();
  ReadTabUserMessage();
  _receiveThread = new Thread(new ThreadStart(StartUp));
  _receiveThread.Start();
  }

   
  /// <summary>
  /// 读取所有用户信息
  /// </summary>
  private void Read_User()
  {
  try
  {
  TabUser.ReadXml(MyPath + "//User.xml");
  }
  catch
  {
  TabUser.TableName = "User";
  TabUser.Columns.Add("UserName", typeof(String));
  TabUser.Columns.Add("UserPwd", typeof(String));
  TabUser.Columns.Add("UserNich", typeof(String));
  TabUser.Columns.Add("UserImg", typeof(String));
  }
  TabUser.Columns.Add("ZX", typeof(Boolean));
  TabUser.Columns.Add("UserIp", typeof(String));
  }

   
  /// <summary>
  /// 新用户上/下线后,更新其好友的(好友列表)
  /// </summary>
  /// <param name="UserName"></param>
  /// <param name="OnLine"></param>
  /// <param name="IpAddress"></param>
  private void UpdateFriendList(string UserName, bool OnLine, string IpAddress)
  { 
  DataTable TabmyFriend = new DataTable();
  TabmyFriend.TableName = UserName;
  string svrlog = null;
  string []UserInformation = new string[2];//UserName + "$" + IpAddress;
  UserInformation[0] = UserName;
  UserInformation[1] = IpAddress;
  IFormatter format = new BinaryFormatter();
  MemoryStream stream = new MemoryStream();
  format.Serialize(stream, UserInformation);
  byte[] ret = stream.ToArray();
  stream.Close();

  if (OnLine)
  {
  svrlog = "cmd::RequestAddFriendList";
  }
  else
  {
  svrlog = "cmd::RequestRemoveFriendList";
  DataRow[] DataRows = TabUser.Select(" UserName = ‘" + UserName + "’");
  if (DataRows.Length > 0)
  {
  DataRows[0]["ZX"] = false;
  DataRows[0]["UserIp"] = "";
  }
  }
  try
  {
  TabmyFriend.ReadXml(MyPath + "//UserFriend//" + TabmyFriend.TableName + ".xml");
  foreach (DataRow myrow in TabmyFriend.Rows)
  {
  if(_transmit_tb.ContainsKey(myrow["UserName"].ToString()))
  {
  Socket _clientSkt = _transmit_tb[myrow["UserName"].ToString()] as Socket;
  _clientSkt.Send(Encoding.Unicode.GetBytes(svrlog));
  _clientSkt.Send(ret);
  }
  }
  }
  catch
  { }
  }


--------------------------------------------------------------------------------


[code=C#][/code /// <summary>
  /// 线程执行体,转发消息
  /// </summary>
  /// <param name="obj">传递给线程执行体的用户名,用以与用户通信</param>
  private void ThreadFunc(object obj)
  {
  //通过转发表得到当前用户套接字
  Socket clientSkt = _transmit_tb[obj] as Socket;


  //主循环 
  while (true)
  {
  try
  {
  //接受第一个数据包。
  //由于程序逻辑结构简单,所以在这里对客户机发送的第一个包内容作逐一判断,
  //这里的实现不够优雅,但不失为此简单模型的一个解决之道。
  byte[] packetBuff = new byte[_maxPacket];
  clientSkt.Receive(packetBuff);
  string _str = Encoding.Unicode.GetString(packetBuff).TrimEnd('/0');
  //如果是发给不在线好友的信息
  if (_str.StartsWith("cmd::FriendMessage"))
  {
  string UserName = _str.Substring("cmd::FriendMessage".Length, 20).Trim();
  string MessageS = _str.Substring("cmd::FriendMessage".Length + 20, _str.Length - "cmd::FriendMessage".Length - 20);
  SaveMessage(obj as string, UserName, MessageS);
  continue;
  }
  //如果是离线请求
  if (_str.StartsWith("cmd::RequestLogout"))
  {
  _transmit_tb.Remove(obj);
  UpdateFriendList((string)obj, false, "");
  // string svrlog = string.Format("[系统消息]用户 {0} 在 {1} 已断开... 当前在线人数: {2}/r/n/r/n", obj, DateTime.Now, _transmit_tb.Count);
  // Console.WriteLine(svrlog);
  //向所有客户机发送系统消息
   
  //foreach (DictionaryEntry de in _transmit_tb)
  //{
  // string _clientName = de.Key as string;
  // Socket _clientSkt = de.Value as Socket;
  // _clientSkt.Send(Encoding.Unicode.GetBytes(svrlog));
  //}
  Thread.CurrentThread.Abort();
  }
  //如果是请求好友列表
  if (_str.StartsWith("cmd::RequestFriendList"))
  {
  SerializeFriendList(obj, clientSkt);  
  // 将该用户不在线时的信息发送给用户
  DataTable TabMessage = ReadMessage(obj as string);
  if (TabMessage != null)
  {
  foreach (DataRow myrow in TabMessage.Rows)
  {
  if (myrow["SendUserName"].ToString() == "System::Message")
  {
  clientSkt.Send(Encoding.Unicode.GetBytes(myrow["Message"].ToString()));
  }
  else
  {
  clientSkt.Send(Encoding.Unicode.GetBytes("cmd::FriendMessage" + myrow["SendUserName"].ToString().PadRight(20, ' ') + myrow["Message"].ToString()));
  }
  }
  }
  //这里不需要再继续接受后继数据包了,跳出当前循环体。
  continue;
  }
  ////如果是请求好友列表
  //if (_str.StartsWith("cmd::RequestOnLineList"))
  //{
  // byte[] onlineBuff = SerializeOnlineList();
  // //先发送响应信号,用户客户机的判断
  // clientSkt.Send(Encoding.Unicode.GetBytes("cmd::RequestOnLineList"));
  // clientSkt.Send(onlineBuff);
  // //这里不需要再继续接受后继数据包了,跳出当前循环体。
  // continue;
  //}
  //查找用户
  if (_str.StartsWith("Find::FindFriend"))
  {
  DataTable TabFind = TabUser.Clone();
  DataRow [] FindRow =null ;
  string UserName = _str.Substring("Find::FindFriend".Length, _str.Length - "Find::FindFriend".Length);
  if (UserName.Equals("Find::WhoOnLine"))
  { //看谁在线
  FindRow = TabUser.Select(" ZX = 1");
  }
  else//精确查找
  {
  FindRow = TabUser.Select("UserName = '" + UserName + "'");
  }
  foreach (DataRow myrow in FindRow)
  {
  TabFind.ImportRow(myrow);
  }
   
  clientSkt.Send(Encoding.Unicode.GetBytes("Find::FindFriend"));
  IFormatter format = new BinaryFormatter();
  MemoryStream stream = new MemoryStream();
  format.Serialize(stream, TabFind);
  stream.Position = 0;
  byte[] ret = new byte[_maxPacket];
  int count = 0;
  count = stream.Read(ret, 0, _maxPacket);
  while (count >0)
  {
  clientSkt.Send(ret);
  count = stream.Read(ret, 0, _maxPacket);
  }
  clientSkt.Send(Encoding.Unicode.GetBytes("Find::FindFriendEnd"));  
  stream.Close();
  TabFind = null;
  FindRow = null;
//这里不需要再继续接受后继数据包了,跳出当前循环体。
  continue;
  }
  //请求添加好友
  if (_str.StartsWith("Find::AddFriendAsk"))
  {
  string UserName = _str.Substring("Find::AddFriendAsk".Length, _str.Length - "Find::AddFriendAsk".Length);
  //通过转发表查找接收方的套接字
  if (_transmit_tb.Count != 0 && _transmit_tb.ContainsKey(UserName))
  {
  Socket receiverSkt = _transmit_tb[UserName] as Socket;
  receiverSkt.Send(Encoding.Unicode.GetBytes("Find::AddFriendAsk" + obj as string));
  }
  //这里不需要再继续接受后继数据包了,跳出当前循环体。
  continue;
  }
  //回复答应添加好友
  if (_str.StartsWith("Find::AddFriendYes"))
  {
  string UserName = _str.Substring("Find::AddFriendYes".Length, _str.Length - "Find::AddFriendYes".Length);
  //// 保存数据 
  DataTable TabmyFriend = new DataTable() ;
  //保存该用户
  TabmyFriend.ReadXml(MyPath + "//UserFriend//" + obj as string + ".xml");
  DataRow newRow = TabmyFriend.NewRow();
  newRow["UserName"] = UserName;
  TabmyFriend.Rows.Add(newRow);
  TabmyFriend.WriteXml(MyPath + "//UserFriend//" + obj as string + ".xml", XmlWriteMode.WriteSchema, false);
  //保存其好友
  TabmyFriend = new DataTable();
  TabmyFriend.ReadXml(MyPath + "//UserFriend//" + UserName + ".xml");
  DataRow newRow1 = TabmyFriend.NewRow();
  newRow1["UserName"] = obj as string;
  TabmyFriend.Rows.Add(newRow1);
  TabmyFriend.WriteXml(MyPath + "//UserFriend//" + UserName + ".xml", XmlWriteMode.WriteSchema, false);
  TabmyFriend = null;
  //更新好友列表
  SerializeFriendList(obj, clientSkt);


--------------------------------------------------------------------------------


<table cellspacing="0" cellpadding="0" border="1" style="border: medium none ; border-collapse: collapse;" class="MsoTableGrid">
  <tbody>
  <tr style="">
  <td width="73" valign="top" style="border: 1pt solid windowtext; padding: 0cm 5.4pt; width: 54.55pt; background-color: transparent;">
  <p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><font size="3"><span style="font-family: 宋体;">企业名称</span><span lang="EN-US"><o:p/></span></font></p>
  </td>
  <td width="162" valign="top" style="border-style: solid solid solid none; border-color: windowtext windowtext windowtext rgb(236, 233, 216); border-width: 1pt 1pt 1pt medium; padding: 0cm 5.4pt; width: 121.85pt; background-color: transparent;">
  <p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><font size="3"><span style="font-family: 宋体;">连锁经营品牌</span><span lang="EN-US"><o:p/></span></font></p>
  </td>
  <td width="96" valign="top" style="border-style: solid solid solid none; border-color: windowtext windowtext windowtext rgb(236, 233, 216); border-width: 1pt 1pt 1pt medium; padding: 0cm 5.4pt; width: 72.3pt; background-color: transparent;">
  <p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><font size="3"><span style="font-family: 宋体;">总部所在地</span><span lang="EN-US"><o:p/></span></font></p>
  </td>
  <td width="82" valign="top" style="border-style: solid solid solid none; border-color: windowtext windowtext windowtext rgb(236, 233, 216); border-width: 1pt 1pt 1pt medium; padding: 0cm 5.4pt; width: 61.8pt; background-color: transparent;">
  <p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><font size="3"><span style="font-family: 宋体;">加盟条件</span><span lang="EN-US"><o:p/></span></font></p>
  </td>
  <td width="141" valign="top" style="border-style: solid solid solid none; border-color: windowtext windowtext windowtext rgb(236, 233, 216); border-width: 1pt 1pt 1pt medium; padding: 0cm 5.4pt; width: 105.7pt; background-color: transparent;">
  <p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><font size="3"><span style="font-family: 宋体;">加盟热线</span><span lang="EN-US"><o:p/></span></font></p>
  </td>
  </tr>


  </tbody>
</table>


--------------------------------------------------------------------------------
   
using System;
using System.Collections.Generic;
using System.Text;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.Windows.Forms;
using System.IO;
using System.Data.SqlClient;


namespace SERVERsocket
{
  class SERVER
  {
  private Thread serverThread;
  private Thread recvThread;
  private TcpListener tcpListener;
  private NetworkStream networkStream;
  private StreamReader streamReader;
  private StreamWriter streamWriter;
  private Socket socketForClient;
  private string message;
  private int operatorNO;
  private bool[] isOperated;

  private void Listen()
  {
  try
  {
  Int32 port = Int32.Parse("2020");
  IPAddress ipAddress = Dns.Resolve("localhost").AddressList[0];
  tcpListener = new TcpListener(IPAddress.Any, port);
  //开始侦听
  tcpListener.Start();
  //返回可以用以处理连接的Socket实例
  socketForClient = tcpListener.AcceptSocket();
  if (socketForClient.Connected)
  {  
  networkStream = new NetworkStream(socketForClient);
  streamReader = new StreamReader(networkStream);
  streamWriter = new StreamWriter(networkStream);
  recvThread = new Thread(new ThreadStart(RecvData));
  recvThread.Start();
  }
  MessageBox.Show("客户端成功连接上服务器!");
  }

  catch (Exception exc)
  {
  MessageBox.Show(exc.Message, "Server提示");
  }
  }

  //接收数据
  private void RecvData()
  {
  string msg = streamReader.ReadLine();
  string[] tokens = msg.Split(new char[] { '#' });
  //MessageBox.Show(tokens[0]);
  //MessageBox.Show(tokens[1]);
  //MessageBox.Show(tokens[2]);

  while (!msg.Equals("clientExit"))
  {
  switch (tokens[0])
  {
  case "c01":
  {
  //MessageBox.Show("开始登陆!");
  //下面写SQL语句,查询对应的帐户密码是否正确,并返回信息
  SqlConnection thisConnection = new SqlConnection("server = localhost;Integrated Security =true;database = security");
  SqlCommand comn = new SqlCommand("select 密码 from 帐户表 where 账号=" + tokens[1], thisConnection);
  thisConnection.Open();
  SqlDataAdapter thisAdapt = new SqlDataAdapter("select * from 帐户表", thisConnection);
  DataSet thisDataSet = new DataSet();
  thisAdapt.Fill(thisDataSet, "帐户表");
  string s = comn.ExecuteScalar().ToString();

  // MessageBox.Show(s);
  // MessageBox.Show(tokens[2]);

  if (s.CompareTo(tokens[2]) == 0)
  {
  streamWriter.Write("1");
  streamWriter.Flush();
  tokens[0].Remove(0);
  // MessageBox.Show("登陆消息已发送");
  }
  else
  {
  streamWriter.Write("1");
  streamWriter.Flush();
  tokens[0].Remove(0);
  // MessageBox.Show("登陆");
  }

  }
  break;

  case "c02":
  {
  //下面写SQL语句,查询对应账户的余额,并返回信息
  SqlConnection thisConnection = new SqlConnection("server = localhost;Integrated Security =true;database = security;");
  SqlDataAdapter thisAdapt = new SqlDataAdapter("select * from 帐户表", thisConnection);
  SqlCommandBuilder thisbuider = new SqlCommandBuilder(thisAdapt);
  SqlCommand thisCommand = thisConnection.CreateCommand();
  thisConnection.Open();
  DataSet thisDataSet = new DataSet();
  thisAdapt.Fill(thisDataSet, "帐户表");
  string s1 = "select 金额 from 帐户表 where 账号=" + tokens[1];
  setMessage("c002#" + s1); //填写账户余额
  SendData();
  tokens[0].Remove(0);
  }
  break;
  case "c03":
  {
  //更改帐户密码的sql语句,完成后返回数据003成功
  SqlConnection thisConnection = new SqlConnection("server = localhost;Integrated Security =true;database = security;");
  SqlDataAdapter thisAdapt = new SqlDataAdapter("select * from 帐户表", thisConnection);
  SqlCommandBuilder thisbuider = new SqlCommandBuilder(thisAdapt);
  SqlCommand thisCommand = thisConnection.CreateCommand();
  thisConnection.Open();
  DataSet thisDataSet = new DataSet();
  thisAdapt.Fill(thisDataSet, "帐户表");
  foreach (DataRow rows in thisDataSet.Tables["帐户表"].Rows)
  {

  string s1 = "select 密码 from 帐户表 where 账号=" + tokens[1];
  if (s1.CompareTo(tokens[1]) == 0)
  {
  thisCommand.CommandText = "update 帐户表 set 密码 = " + tokens[3] + "where 账号=" + tokens[1];
  setMessage("c003#1"); //修改密码成功
  SendData();
  tokens[0].Remove(0);
  }
  else
  {
  setMessage("c003#2"); //修改密码失败
  SendData();
  tokens[0].Remove(0);
  }
  }
  }
  break;


--------------------------------------------------------------------------------

case "c04":
  {
  operatorNO = Int32.Parse(tokens[1]);
  if (isOperated[operatorNO]) //这句要查下,c#中的bool初始值是什么?true还是false
  {


  SendData();
  isOperated[operatorNO] = true; //将“已操作”标记设置为true
  }
  else
  {
  //执行转账操作的SQL语句,完成后并返回信息
  SqlConnection thisConnection = new SqlConnection("server = localhost;Integrated Security =true;database = security;");
  SqlDataAdapter thisAdapt = new SqlDataAdapter("select * from 帐户表", thisConnection);
  thisConnection.Open();
  SqlCommand thisCommand = thisConnection.CreateCommand();
  DataSet thisDataSet = new DataSet();
  thisAdapt.Fill(thisDataSet, "帐户表");

  string s2 = "select 金额 from 帐户表 where 账号=" + tokens[1];
  string s3 = "select 金额 from 帐户表 where 账号=" + tokens[1];

  if (s2.CompareTo(tokens[3]) < 0)
  setMessage("c004#1");
  else if (s3 == null)
  setMessage("c004#2");
  else
  {
  foreach (DataRow rows in thisDataSet.Tables["帐户表"].Rows)
  {
  if (rows["账号"].ToString() == tokens[1])
  thisCommand.CommandText = "update 帐户表 set 金额 = 金额 -" + tokens[3] + "where 账号=" + tokens[1];
  if (rows["账号"].ToString() == tokens[2])
  thisCommand.CommandText = "update 帐户表 set 金额 = 金额 +" + tokens[3] + "where 账号=" + tokens[2];
  }

  setMessage("c004#3");
  }
  SendData();
  tokens[0].Remove(0);

  isOperated[operatorNO] = true; //将“已操作”标记设置为true

  }

  }
  break;
  case "c05":
  {
  operatorNO = Int32.Parse(tokens[1]);
  if (isOperated[operatorNO]) //这句要查下,c#中的bool初始值是什么?true还是false
  {
  SendData();
  isOperated[operatorNO] = true; //将“已操作”标记设置为true
  }
  else
  {
  //执行转账操作的SQL语句,完成后并返回信息
   
  }
  SendData();
  tokens[0].Remove(0);

  isOperated[operatorNO] = true; //将“已操作”标记设置为true
  }
  break;  
  }
  msg = streamReader.ReadLine();  
   
  }  
  MessageBox.Show("一名客户退出");
  ReleaseResource();
  startServer();  
  }

  public void setMessage(string message)
  {
  this.message = message;
  }

  private void SendData()
  {
  streamWriter.Write(message);
  streamWriter.Flush();
   
  //streamWriter.Close();
  }

  private void ReleaseResource()
  {
  if (networkStream != null)
  {
  networkStream.Close();
  streamReader.Close();
  streamWriter.Close();
  socketForClient.Shutdown(SocketShutdown.Both);
  socketForClient.Close();
  tcpListener.Stop();
  }
   
  }

  public void startServer()
  {
  serverThread = new Thread(new ThreadStart(Listen));
  serverThread.Start();
  }

  public void serverExit()
  {
  string exitMsg = "serverExit"; //要退出时,发送exit信息给服务器
  setMessage(exitMsg);
  SendData();
  ReleaseResource();
  }
  }

--------------------------------------------------------------------------------

public partial class BankClient
  {


  private NetworkStream networkStream;
  private StreamReader streamReader;
  private StreamWriter streamWriter;
  private TcpClient myclient;
  private Thread recvThread;
  private Thread sendThread;
  private Thread serverThread;
  private bool flag = true;

  private void Connection()
  {
  try
  {
  Int32 port = 8888;
  myclient = new TcpClient("10.1.1.10", port);
  }
  catch
  {
  MessageBox.Show("没有连接到银行服务器!");
  }

  networkStream = myclient.GetStream();
  streamReader = new StreamReader(networkStream);
  streamWriter = new StreamWriter(networkStream);

  // recvThread = new Thread(new ThreadStart(RecvData));
  // recvThread.Start();
  MessageBox.Show("连接到银行服务器!");
   
  }

  private void RecvData()
  {
   
  string s = streamReader.ReadLine();
  string[] tokens = s.Split(new char[] { '#' });
   

  while (!s.Equals("severExit"))
  {
  if (tokens[0] == "1")
  {
  SqlConnection thisConnection = new SqlConnection("server = localhost;Integrated Security = true;database = security;");
  SqlDataAdapter thisAdapt = new SqlDataAdapter("select * from 转账接口表", thisConnection);
  SqlCommandBuilder thisbuider = new SqlCommandBuilder(thisAdapt);
  SqlCommand thisCommand = thisConnection.CreateCommand();
  DataSet thisSet = new DataSet();
  thisAdapt.Fill(thisSet, "转账接口表");
  thisConnection.Open();
  // thisCommand.CommandText = "update 转账接口表 set 标志位 = 3" + "where 转账序号=" + tokens[1];
  thisCommand.CommandText = "delete from 转账接口表 where 转账序号=" + tokens[1];
  thisCommand.ExecuteNonQuery();
  flag = true;
   
  }
  else flag = false;
  s = streamReader.ReadLine();
  }

  ReleaseResouce();
  }

  private void SendData()
  {
  SqlConnection thisConnection = new SqlConnection("server = localhost;Integrated Security = true;database = security;");
  SqlDataAdapter thisAdapt = new SqlDataAdapter("select * from 转账接口表", thisConnection);
  SqlCommandBuilder thisbuider = new SqlCommandBuilder(thisAdapt);
  SqlCommand thisCommand = thisConnection.CreateCommand();
  DataSet thisSet = new DataSet();
  thisAdapt.Fill(thisSet, "转账接口表");
  thisConnection.Open();
  foreach (DataRow rows in thisSet.Tables["转账接口表"].Rows)
  {
  if (rows["标志位"].ToString() == "1")
  {
  string s;
  s = rows["转账序号"].ToString() + '#' + rows["发起端账号"].ToString() + '#' + rows["接收端账号"].ToString() + '#' + rows["发生金额"] + '#' + rows["标志位"].ToString();

  if (flag)
  {
  streamWriter = new StreamWriter(networkStream);
  streamWriter.WriteLine(s);
  streamWriter.Flush();
  System.Threading.Thread.Sleep(5000);
   
  }
  else
  {
  //将数据读入资金变更表
  thisCommand.CommandText = "delete from 转账接口表 where 标志位= '3'";
  }
  }
  }

  }

  private void ReleaseResouce()
  {
  networkStream.Close();
  streamReader.Close();
  streamWriter.Close();
  sendThread.Abort();
  //serverThread.Abort();
  myclient.Close();
  }

  public void startBankClient( )
  {
  serverThread = new Thread(new ThreadStart(Connection));
  serverThread.Start();
  int row = 0;
  SqlConnection thisConnection = new SqlConnection("server = localhost;Integrated Security = true;database = security;");
  SqlDataAdapter thisAdapt = new SqlDataAdapter("select * from 转账接口表", thisConnection);
  SqlCommandBuilder thisbuider = new SqlCommandBuilder(thisAdapt);
  DataSet thisSet = new DataSet();
  thisAdapt.Fill(thisSet, "转账接口表");
  while (true)
  {
  foreach (DataRow rows in thisSet.Tables["转账接口表"].Rows)
  {
  row++;
  }

  if (row > 0)
  {
  SendData();
  RecvData();
  }
  System.Threading.Thread.Sleep(5000);

  }
  }

  public void exitBankClient( )
  {
  streamWriter.Flush();
  ReleaseResouce();

  }
  } 
}

--------------------------------------------------------------------------------
 


case "c02":
  {
  //下面写SQL语句,查询对应账户的余额,并返回信息
  SqlConnection thisConnection = new SqlConnection("server = localhost;Integrated Security =true;database = security;");
  SqlDataAdapter thisAdapt = new SqlDataAdapter("select * from 帐户表", thisConnection);
  SqlCommandBuilder thisbuider = new SqlCommandBuilder(thisAdapt);
  SqlCommand thisCommand = thisConnection.CreateCommand();
  thisConnection.Open();
  DataSet thisDataSet = new DataSet();
  thisAdapt.Fill(thisDataSet, "帐户表");
  string s1 = "select 金额 from 帐户表 where 账号=" + tokens[1];
  setMessage("c002#" + s1); //填写账户余额
  SendData();
  tokens[0].Remove(0);
  }
  break;
  case "c03":
  {
  //更改帐户密码的sql语句,完成后返回数据003成功
  SqlConnection thisConnection = new SqlConnection("server = localhost;Integrated Security =true;database = security;");
  SqlDataAdapter thisAdapt = new SqlDataAdapter("select * from 帐户表", thisConnection);
  SqlCommandBuilder thisbuider = new SqlCommandBuilder(thisAdapt);
  SqlCommand thisCommand = thisConnection.CreateCommand();
  thisConnection.Open();
  DataSet thisDataSet = new DataSet();
  thisAdapt.Fill(thisDataSet, "帐户表");
  foreach (DataRow rows in thisDataSet.Tables["帐户表"].Rows)
  {


  string s1 = "select 密码 from 帐户表 where 账号=" + tokens[1];
  if (s1.CompareTo(tokens[1]) == 0)
  {
  thisCommand.CommandText = "update 帐户表 set 密码 = " + tokens[3] + "where 账号=" + tokens[1];
  setMessage("c003#1"); //修改密码成功
  SendData();
  tokens[0].Remove(0);
  }
  else
  {
  setMessage("c003#2"); //修改密码失败
  SendData();
  tokens[0].Remove(0);
  }
  }
  } 

--------------------------------------------------------------------------------


C# code
using System;

using System.Collections.Generic;

using System.Text;

using System.Net.Mail;

using System.Diagnostics;

namespace MailTest

{

     class Program

     {

         static void Main(string[] args)

         {

              Encoding encoding = Encoding.GetEncoding("GB2312");

              MailAddress from = new MailAddress("youmailname@163.com", "19850101", encoding);

              MailAddress to = new MailAddress("youmailname@163.com");

              MailMessage mail = new MailMessage(from, to);

              mail.Subject = "test";

              mail.Body = "hello world";

              mail.SubjectEncoding = encoding;

              mail.BodyEncoding = encoding;

              SmtpClient smtp = new SmtpClient("smtp.163.com");

              smtp.DeliveryMethod = SmtpDeliveryMethod.Network;

              smtp.UseDefaultCredentials = true;

            smtp.Credentials = new System.Net.NetworkCredential("rjgcwwdz@163.com", "19850101");

              smtp.Send(mail);

         }

     }

}

 


--------------------------------------------------------------------------------

using System;
using System.Collections.Generic;
using System.Text;
using System.Net;
using System.IO;
using System.Net.Sockets;
using System.Threading;


namespace MyQQSer
{
  class Serv
  {
  private TcpListener listenr;
  private Thread thread;
  private bool isClose = false; //结束程序是退出循环
  private Socket[] sock = new Socket[50];

  public Serv()
  {
  Listener();
  }

  ~Serv()
  {
  isClose = true;
  for (int i = 0; i < sock.Length; i++)
  {
  if (sock[i] != null)
  sock[i].Close();
  listenr.Stop();
  }
  }

  /// <summary>
  /// 开始监听端口
  /// </summary>
  public void Listener()
  {
  if (listenr == null)
  listenr = new TcpListener(IPAddress.Parse("127.0.0.1"), 5000);
  listenr.Start();
  if (thread == null)
  thread = new Thread(new ThreadStart(ReciverMessage));
  thread.IsBackground = true;
  thread.Start();
  }

  /// <summary>
  /// 接收数据
  /// </summary>
  private void ReciverMessage()
  {
  int count; //可用套结字索引
  count = GetCount();
  bool loop = true;
  if (count == -1) 
  loop = false;
  if (loop)
  {
  while (true)
  {
  // 判断是否退出循环
  if (isClose)
  break;  
  sock[count] = listenr.AcceptSocket();
  Thread t = new Thread(new ThreadStart(ReciverMessage));
  t.IsBackground = true;
  t.Start();
  // 接受客户端数据
  while (true)
  {
  byte[] buffs = new byte[100];
  if (sock[count].Connected)
  {
  try
  {
  sock[count].Receive(buffs);
  string message = Encoding.Default.GetString(buffs);
  Console.WriteLine(message);
  SendToAll(buffs);
  }
  catch (Exception ex)
  {

  }
  }
  }
  }
  }
  Thread.CurrentThread.Abort();
  }

  // 得到可用套结字索引
  private int GetCount()
  {
  for (int i = 0; i < sock.Length; i++)
  if (sock[i] == null)
  return i;
  return -1;
  }

  // 发送消息给所有人
  private void SendToAll(byte[] buff)
  {
  for (int i = 0; i < sock.Length; i++)
  {
  if (sock[i] != null)
  {
  if (sock[i].Connected)
  {
  sock[i].Send(buff);
  }
  }
  }
  }
  }
}


--------------------------------------------------------------------------------

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


namespace TestClient
{
  public partial class Form1 : Form
  {
  private TcpClient client;
  private Thread t;
  private Socket sock;
  private bool close = false;

  public Form1()
  {
  InitializeComponent();
  }

  // 连接
  private void btnConnect_Click(object sender, EventArgs e)
  {
  if(client == null)
  client = new TcpClient(new IPEndPoint(IPAddress.Parse("127.0.0.1"), int.Parse(txtLoalPort.Text)));

  if (t == null)
  t = new Thread(new ThreadStart(ReciverMessage));
  t.IsBackground = true;
  t.Start();
  btnSend.Enabled = true;
  btnConnect.Enabled = false;
  }
   
  // 接收消息
  private void ReciverMessage()
  {
  client.Connect(IPAddress.Parse(txtSerIP.Text), int.Parse(txtSerPort.Text));
  while (true)
  {
  if (close)
  break;
  //NetworkStream nws = client.GetStream();
  //StreamReader sr = new StreamReader(nws);
  //string message = sr.ReadToEnd();
  //sr.Close();
  if(sock == null)
  sock = client.Client;
  byte[] buff = new byte[100];
  sock.Receive(buff);
  string message = Encoding.Default.GetString(buff);
  this.lstMessage.Items.Add(message);  
  }
  Thread.CurrentThread.Abort();
  }

  // 发送消息
  private void btnSend_Click(object sender, EventArgs e)
  {
  string message = this.txtInput.Text;
  byte[] buff = Encoding.Default.GetBytes(message);
  sock.Send(buff);
  txtInput.Text = "";
  }

  private void Form1_FormClosing(object sender, FormClosingEventArgs e)
  {
  close = true;
  sock.Close();
  }
  }
}


--------------------------------------------------------------------------------

 

贴一个服务器端异步接受SOKCET请求的代码:


 

C# code
public class XmlSocket
    {

        //异步socket诊听
        // Incoming data from client.从客户端传来的数据
        public static string data = null;

        // Thread signal.线程 用一个指示是否将初始状态设置为终止的布尔值初始化 ManualResetEvent 类的新实例。
        public static ManualResetEvent allDone = new ManualResetEvent(false);
        //static void Main(string[] args)
        //{
        //    StartListening();
        //}

        public static void StartListening()
        {
            // Data buffer for incoming data. 传入数据缓冲
            byte[] bytes = new Byte[1024];
            // Establish the local endpoint for the socket. 建立本地端口
            // The DNS name of the computer
            // running the listener is "host.contoso.com".

            IPAddress ipAddress;
            String ipString = ConfigurationManager.AppSettings.Get("SocketIP");
            if (ipString==null || ipString ==String.Empty)
            {
                IPHostEntry ipHostInfo = Dns.GetHostEntry(Dns.GetHostName());
                ipAddress = ipHostInfo.AddressList[0];
            }
            else
            {
                ipAddress = IPAddress.Parse(ipString);
            }

            int port;
            String portString = ConfigurationManager.AppSettings.Get("SocketPort");
            if (portString==null || portString==String.Empty)
            {
                port = 11001;
            }
            else
            {
                port = int.Parse(portString);
            }
            IPEndPoint localEndPoint = new IPEndPoint(ipAddress, port);

            // Create a TCP/IP socket.
            Socket listener = new Socket(AddressFamily.InterNetwork,
             SocketType.Stream, ProtocolType.Tcp);

            // Bind the socket to the local endpoint and listen for incoming connections.绑定端口和数据
            try
            {
                listener.Bind(localEndPoint);
                listener.Listen(100);

                while (true)
                {
                    // Set the event to nonsignaled state.设置无信号状态的事件
                    allDone.Reset();
                    // Start an asynchronous socket to listen for connections.重新 启动异步连接
                    listener.BeginAccept(new AsyncCallback(AcceptCallback), listener);
                    // Wait until a connection is made before continuing.等待连接创建后继续
                    allDone.WaitOne();
                }
            }
            catch (Exception e)
            {
                //
            }
        }

        public static void AcceptCallback(IAsyncResult ar)
        {
            try
            {
                // Signal the main thread to continue.接受回调方法 该方法的此节向主应用程序线程发出信号,
                //让它继续处理并建立与客户端的连接
                allDone.Set();
                // Get the socket that handles the client request.获取客户端请求句柄
                Socket listener = (Socket)ar.AsyncState;
                Socket handler = listener.EndAccept(ar);
                // Create the state object.
                StateObject state = new StateObject();
                state.workSocket = handler;
                handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                 new AsyncCallback(ReadCallback), state);
            }
            catch (Exception e)
            {
                //
            }
        }

        /// <summary>
        /// 与接受回调方法一样,读取回调方法也是一个 AsyncCallback 委托。
        /// 该方法将来自客户端套接字的一个或多个字节读入数据缓冲区,然后再次调用 BeginReceive 方法,直到客户端发送的数据完成为止。
        /// 从客户端读取整个消息后,在控制台上显示字符串,并关闭处理与客户端的连接的服务器套接字。
        /// </summary>
        /// <param name="ar">IAsyncResult 委托</param>
        public static void ReadCallback(IAsyncResult ar)
        {
            try
            {
                String content = String.Empty;
                // Retrieve the state object and the handler socket创建自定义的状态对象 from the asynchronous state object.
                StateObject state = (StateObject)ar.AsyncState;
                Socket handler = state.workSocket;//处理的句柄
                // Read data from the client socket. 读出
                int bytesRead = handler.EndReceive(ar);
                if (bytesRead > 0)
                {
                    //业务代码
                    string result = DoSomeThing(...);
                    String len = Encoding.UTF8.GetBytes(result).Length.ToString().PadLeft(8, '0');
                    log.writeLine(len);
                    Send(len + result, handler);
                }
            }
            catch (Exception e)
            {
                //
            }

        }
        private static void Send(String data, Socket handler)
        {
            try
            {
                // Convert the string data to byte data using UTF8 encoding.
                byte[] byteData = Encoding.UTF8.GetBytes(data);
                // Begin sending the data to the remote device.
                handler.BeginSend(byteData, 0, byteData.Length, 0,
                 new AsyncCallback(SendCallback), handler);
            }
            catch (Exception e)
            {
                //
            }
        }
        /// <summary>
        /// 发送
        /// </summary>
        /// <param name="ar"></param>
        private static void SendCallback(IAsyncResult ar)
        {
            try
            {
                // Retrieve the socket from the state object.
                Socket handler = (Socket)ar.AsyncState;

                // Complete sending the data to the remote device.向远端发送数据
                int bytesSent = handler.EndSend(ar);
                StateObject state = new StateObject();
                state.workSocket = handler;

                handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,new AsyncCallback(ReadCallback), state);
                handler.Shutdown(SocketShutdown.Both);
                handler.Close();
            }
            catch (Exception e)
            {
//
            }
        }

        public static void StopListening()
        {
            allDone.Close();
            log.close();
        }

        /// <summary>
        /// 具体处理业务的方法
        /// </summary>
        /// <returns></returns>
        private static string DoSomething(int i)
        {
            //具体业务代码,返回需要返回的字符串信息
        }
        /// <summary>
        /// 写日志方法
        /// </summary>
        /// <param name="strLog">写入内容</param>
        public static void WriteLog(string strLog)
        {
             //写入日志代码
        }
    }


--------------------------------------------------------------------------------

http://www.lumisoft.ee/lsWWW/download/downloads/Net


--------------------------------------------------------------------------------
 
http://topic.csdn.net/u/20080623/08/4bbd2475-45f1-42e3-a613-16b094759ade.html?seed=66789082

--------------------------------------------------------------------------------


public partial class Form1 : Form
  {
  private bool isExit = false;
  System.Collections.ArrayList clientList = new System.Collections.ArrayList();
  TcpListener listener;
  //private delegate void AcceptConner();


  #region 用于一个线程操作另一个线程的控件
  private delegate void SetListBoxCallback(string str);
  private SetListBoxCallback setListBoxCallBack;

  private delegate void SetRichTextBoxCallback(string str);
  private SetRichTextBoxCallback setRichTextBoxCallBack;

  private delegate void SetComboBoxCallback(string str);
  private SetComboBoxCallback setComboBoxCallBack;

  private delegate void RemoveComboBoxCallback(ReadWriteObject readWriteObject);
  private RemoveComboBoxCallback removeComboBoxCallBack;
  #endregion

  //用于线程的同步操作,初始状态,使用手动重置方式
  private EventWaitHandle allDone = new EventWaitHandle(false, EventResetMode.ManualReset);

  public Form1()
  {
  InitializeComponent();
  listBoxStatus.HorizontalScrollbar = true;//设置水平滚动条
  setListBoxCallBack = new SetListBoxCallback(SetListBox);//状态显示

  setRichTextBoxCallBack = new SetRichTextBoxCallback(SetReceiveText);//数据发送和信息接收

  setComboBoxCallBack = new SetComboBoxCallback(SetComboBox);//连接服务器客户端

  removeComboBoxCallBack = new RemoveComboBoxCallback(RemoveComboBoxItems);//客户信息移出

  }

  //开始服务器....!!!!
  private void buttonStrat_Click(object sender, EventArgs e)
  {
  //侦听客户连接请求
  ThreadStart ts = new ThreadStart(AcceptConnet);
  Thread myThread = new Thread(ts);
  myThread.Start();
  buttonStrat.Enabled = false;
  buttonStop.Enabled = true;
  }

  private void AcceptConnet()
  {
  //AcceptConner ac = delegate
  //{
  IPAddress ip = IPAddress.Parse("127.0.0.1");
  listener = new TcpListener(ip, 7100);
  listener.Start();
  while (isExit == false)
  {
  try
  {
  allDone.Reset();
  //引用在异步操作完成时调用的回调方法
  AsyncCallback callback = new AsyncCallback(AcceptTcpClientCallBack);
  listBoxStatus.Invoke(setListBoxCallBack, "开始等待客户的连接...");
  //开始异步接收客户的连接
  listener.BeginAcceptTcpClient(callback, listener);
  //阻塞当前线程,直到接收到客户的连接
  allDone.WaitOne();
  }
  catch (Exception e1)
  {
  listBoxStatus.Invoke(setListBoxCallBack, e1.Message);
  return;
  }
  }
  //};
  //this.Invoke(ac);
  }
  //异步操作完成时调用的回调的方法
  private void AcceptTcpClientCallBack(IAsyncResult ar)
  {
  allDone.Set();
  TcpListener myListener = (TcpListener)ar.AsyncState;
  //异步接收传入的连接,并建立新的TcpClient对象处理信息
  TcpClient client = myListener.EndAcceptTcpClient(ar);

  listBoxStatus.Invoke(setListBoxCallBack, ("已接收客户的连接:"+client.Client.RemoteEndPoint));
  cbx_sender.Invoke(setComboBoxCallBack, ("客户:"+client.Client.RemoteEndPoint));
  ReadWriteObject rwo = new ReadWriteObject(client);
  clientList.Add(rwo);
  SendString(rwo, "服务器已接收连接,请通话!!!");
  rwo._netStream.BeginRead(rwo._readByte, 0, rwo._readByte.Length, ReadCallBack, rwo);
  }
  //从客户端读取信息处理的异步回调方法
  private void ReadCallBack(IAsyncResult ar)
  {
  ReadWriteObject rwo = (ReadWriteObject)ar.AsyncState;
  try
  {  
  int count = rwo._netStream.EndRead(ar);
  richTextBoxReceive.Invoke(setRichTextBoxCallBack,string.Format("[来自{0}]{1}",rwo._client.Client.RemoteEndPoint,
  System.Text.Encoding.UTF8.GetString(rwo._readByte,0,count)));
  if (isExit == false)
  {
  rwo.InitReadArray();
  rwo._netStream.BeginRead(rwo._readByte, 0, rwo._readByte.Length, ReadCallBack, rwo);
  }
  }
  catch (Exception e2)
  {
  listBoxStatus.Invoke(setListBoxCallBack, e2.Message);
  cbx_sender.Invoke(removeComboBoxCallBack, rwo);
  }
  }
  //向客户端发送数据的方法
  private void SendString(ReadWriteObject rwo,string str)
  {
  try
  {
  rwo._writeByte = System.Text.Encoding.UTF8.GetBytes(str+"/r/n");
  rwo._netStream.BeginWrite(rwo._writeByte, 0, rwo._writeByte.Length, new AsyncCallback(SendCallBack), rwo);
  rwo._netStream.Flush();
  listBoxStatus.Invoke(setListBoxCallBack,string.Format("向{0}发送:{1}",rwo._client.Client.RemoteEndPoint,str));
  }
  catch (Exception e3)
  {
  listBoxStatus.Invoke(setListBoxCallBack, e3.Message);
  cbx_sender.Invoke(removeComboBoxCallBack, rwo);
  }
  }

  private void SendCallBack(IAsyncResult ar)
  {
  ReadWriteObject rwo = (ReadWriteObject)ar.AsyncState;
  try
  {
  rwo._netStream.EndWrite(ar);
  }
  catch(Exception e4) {
  listBoxStatus.Invoke(setListBoxCallBack, e4.Message);
  cbx_sender.Invoke(removeComboBoxCallBack, rwo);
  }
  }

  //状态显示
  private void SetListBox(string str)
  {
  listBoxStatus.Items.Add(str);
  listBoxStatus.SelectedIndex = listBoxStatus.Items.Count - 1;
  listBoxStatus.ClearSelected();
  }
  //接收客户端信息
  private void SetReceiveText(string str)
  {
  richTextBoxReceive.AppendText(str);
  }
  //添加客户
  private void SetComboBox(string str)
  {
  cbx_sender.Items.Add(str);
  }
  //移出客户
  private void RemoveComboBoxItems(ReadWriteObject rwo)
  {
  int index = clientList.IndexOf(rwo);
  cbx_sender.Items.RemoveAt(index);
  }
  //服务器停止  
  private void buttonStop_Click(object sender, EventArgs e)
  {
  isExit = true;
  allDone.Set();
  buttonStrat.Enabled = true;
  buttonStop.Enabled = false;
  }

  private void buttonSend_Click(object sender, EventArgs e)
  {
  int index = cbx_sender.SelectedIndex;
  if (index == -1)
  {
  MessageBox.Show("请先选择接收方,在发送数据");
  }
  else
  {
  ReadWriteObject rwo =(ReadWriteObject)clientList[index];
  SendString(rwo, richTextBoxSend.Text);
  richTextBoxSend.Clear();
  }
  }
  //窗体关闭!!!
  private void Form1_FormClosing(object sender, FormClosingEventArgs e)
  {
  buttonStop_Click(null, null);
  }
  }


--------------------------------------------------------------------------------

是个SOCKET文件发送和接收程序:
Server端:
[code=C#]
  public   class   StateObject
  {
            public   Socket   workSocket   =   null;
            public   const   int   BUFFER_SIZE   =   1024;
            public   byte[]   buffer   =   new   byte[BUFFER_SIZE];
            public   StringBuilder   sb   =   new   StringBuilder();
            public   string   file   =   " ";
            public   FileStream   stream;
            public   int   _seek   =   0;
  }
                AutoResetEvent   autoEvent   =   new   AutoResetEvent(false);
                bool   isListen   =   true;
                Socket   _listener   =   new   Socket(AddressFamily.InterNetwork,   SocketType.Stream,         ProtocolType.Tcp);
                static   IPAddress   hostIP   =   (Dns.Resolve(IPAddress.Any.ToString())).AddressList[0];
                IPEndPoint   localEP   =   new   IPEndPoint(hostIP,   5000);
              _listener.Bind(localEP);
              _listener.Listen(100);
                       
              Thread   socekThread   =   new   Thread(new   ThreadStart(Listen));
              socekThread.IsBackground   =   true;
              socekThread.Start();
                //监听线程
                private   void   Listen()
                {
                        while   (isListen)
                        {
                                //接收到一个客户端请          
                                    autoEvent.Reset();
                                _listener.BeginAccept(new   AsyncCallback(Listen_Callback),   _listener);
                                autoEvent.WaitOne();
                        }
                }


                private   void   Listen_Callback(IAsyncResult   ar)
                {
                        autoEvent.Set();
                        Socket   s   =   (Socket)ar.AsyncState;
                        Socket   s2   =   s.EndAccept(ar);
                        StateObject   _object   =   new   StateObject();
                        _object.workSocket   =   s2;
                        s2.BeginReceive(_object.buffer,   0,   1024,   0,   new   AsyncCallback(Read_Callback),   _object);
                }

                private   void   Read_Callback(IAsyncResult   ar)
                {
                        StateObject   _object   =   (StateObject)ar.AsyncState;
                        Socket   s=_object.workSocket;
                        int   read   =   s.EndReceive(ar);
                        if   (_object.file   ==   " ")
                        {
                                _object.file   =   "c:// "   +   System.DateTime.Now.ToOADate().ToString()   +   ".rar ";
                                _object.stream   =   new   FileStream(_object.file,   FileMode.Create);
                        }
                        if   (read   >   0)
                        {
                                _object.stream.Write(_object.buffer,   0,   _object.buffer.Length);
                                _object._seek   +=   _object.buffer.Length;
                                //_object.sb.Append(Encoding.UTF8.GetString(_object.buffer));
                                s.BeginReceive(_object.buffer,   0,   _object.buffer.Length,   0,   new   AsyncCallback(Read_Callback),   _object);
                        }
                        else
                        {
                                _object.stream.Close();
                                s.Close();
                        }
                }
[/code]

Client:
                                IPHostEntry   ipHost   =   Dns.GetHostEntry(Dns.GetHostName());
                                IPAddress   ipAddr   =   ipHost.AddressList[0];
                                IPEndPoint   ipEndPoint   =   new   IPEndPoint(ipAddr,   5000);

                                //   Create   a   TCP   socket.
                                Socket   client   =   new   Socket(AddressFamily.InterNetwork,
                                                SocketType.Stream,   ProtocolType.Tcp);

                                //   Connect   the   socket   to   the   remote   endpoint.
                                client.Connect(ipEndPoint);

                                //   There   is   a   text   file   test.txt   located   in   the   root   directory.
                                //string   fileName   =   "C://test.txt ";

                                //   Send   file   fileName   to   remote   device
                                //Console.WriteLine( "Sending   {0}   to   the   host. ",   fileName);
                                byte[]   buf   =   Encoding.UTF8.GetBytes(textBox1.Text);
                                string   file   =   " ";//发送的文件

                                client.BeginSendFile(@file,   new   AsyncCallback(ConnectCallback),   client);
                                autoEvent.WaitOne();
                                //client.SendFile(@file);
                                //   Release   the   socket.
                                client.Shutdown(SocketShutdown.Both);
                                client.Close();


--------------------------------------------------------------------------------

C# code

public partial class Form1 : Form
    {
        private TcpClient client;
        private bool isExit = false;
        private NetworkStream networkStream;
        private EventWaitHandle allDone = new EventWaitHandle(false, EventResetMode.ManualReset);
        #region 用于一个线程操作另一个线程的控件
        private delegate void SetListBoxCallback(string str);
        private SetListBoxCallback setListBoxCallBack;

        private delegate void SetRichTextBoxCallback(string str);
        private SetRichTextBoxCallback setRichTextBoxCallBack;

        #endregion
        public Form1()
        {
            InitializeComponent();
            listBoxStatus.HorizontalScrollbar = true;
            setListBoxCallBack = new SetListBoxCallback(SetListBox);
            setRichTextBoxCallBack = new SetRichTextBoxCallback(SetReceiveText);
        }

        //状态显示
        private void SetListBox(string str)
        {
            listBoxStatus.Items.Add(str);
            listBoxStatus.SelectedIndex = listBoxStatus.Items.Count - 1;
            listBoxStatus.ClearSelected();
        }
        //接收客户端信息
        private void SetReceiveText(string str)
        {
            richTextBoxReceive.AppendText(str);
        }
        //连接服务器....
        private void buttonConnet_Click(object sender, EventArgs e)
        {
            client = new TcpClient(AddressFamily.InterNetwork);
            //得到服务器IP
            IPAddress ip= IPAddress.Parse("127.0.0.1");
            //创建一个委托,并知名在异步操作完成时执行的方法
            AsyncCallback callback = new AsyncCallback(RequestCallBack);

            allDone.Reset();
            client.BeginConnect(ip, 7100, RequestCallBack, client);
        }

        private void RequestCallBack(IAsyncResult ar)
        {
            allDone.Set();
            try
            {
                client = (TcpClient)ar.AsyncState;
                client.EndConnect(ar);
                listBoxStatus.Invoke(setListBoxCallBack, string.Format("与服务器{0}连接成功", client.Client.RemoteEndPoint));

                networkStream = client.GetStream();

                ReadObject readObject = new ReadObject(networkStream, client.ReceiveBufferSize);
                networkStream.BeginRead(readObject.bytes, 0, readObject.bytes.Length, ReadCallBack, readObject);
            }
            catch (Exception e1)
            {
                listBoxStatus.Invoke(setListBoxCallBack, e1.Message);
                return;
            }
        }
        //异步操作完成时执行的回调调用的方法
        private void ReadCallBack(IAsyncResult ar)
        {
            try
            {
                ReadObject ro = (ReadObject)ar.AsyncState;
                int count = ro.netStream.EndRead(ar);
                richTextBoxReceive.Invoke(setRichTextBoxCallBack, System.Text.Encoding.UTF8.GetString(ro.bytes, 0, count));
                if (isExit == false)
                {
                    ro = new ReadObject(networkStream, client.ReceiveBufferSize);
                    networkStream.BeginRead(ro.bytes, 0, ro.bytes.Length, ReadCallBack, ro);
                }
            }
            catch (Exception e2)
            {
                listBoxStatus.Invoke(setListBoxCallBack, e2.Message);
                return;
            }
        }
        //发送数据
        private void SendString(string str)
        {
            try
            {
                byte[] by = System.Text.Encoding.UTF8.GetBytes(str+"/r/n");
                networkStream.BeginWrite(by, 0, by.Length, new AsyncCallback(SendCallBack), networkStream);
                networkStream.Flush();
            }catch(Exception e3){
                listBoxStatus.Invoke(setListBoxCallBack, e3.Message);
                return;
            }
        }
        //发送数据回调的方法
        private void SendCallBack(IAsyncResult ar)
        {
            try
            {
                networkStream.EndWrite(ar);
            }
            catch (Exception e4)
            {
                listBoxStatus.Invoke(setListBoxCallBack, e4.Message);
                return;
            }
        }

        private void buttonSend_Click(object sender, EventArgs e)
        {
            SendString(richTextBoxSend.Text);
            richTextBoxSend.Clear();
        }

        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            isExit = true;
            allDone.Set();
        }
    }

 


--------------------------------------------------------------------------------


学习一下,tcp异步请大家多提意见,
 public void TCPList()
  {


  try
  {
  myIP = IPAddress.Parse(textBox2.Text);

  }
  catch { MessageBox.Show("您输入的IP地址格式不正确,请重新输入!"); }
  try
  {
  int TCP_Port = Convert.ToInt16(textBox4.Text.Trim());
  ServerSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
  ServerInfo = new IPEndPoint(myIP, TCP_Port);
  //ServerInfo = new IPEndPoint(IPAddress.Any, this.GetPort("TCPPort"));
  ServerSocket.Bind(ServerInfo);//将SOCKET接口和IP端口绑定
  ServerSocket.Listen(10);//开始监听,并且挂起数为10

  ClientSocket = new Socket[65535];//为客户端提供连接个数
  MsgBuffer = new byte[65535];//消息数据大小
  ClientNumb = 0;//数量从0开始统计

  ServerThread = new Thread(RecieveAccept);//将接受客户端连接的方法委托给线程
  ServerThread.Start();//线程开始运行

  CheckForIllegalCrossThreadCalls = false;//不捕获对错误线程的调用
  statusBarPanel1.ForeColor = Color.Green ;
  this.statusBarPanel1.Text = "服务正在运行" + " 运行端口:" + TCP_Port.ToString();
  this.txtlink.AppendText("服务于 " + DateTime.Now.ToString() + " 开始运行./n");

  //
  }
  catch (Exception ee)
  {
  statusBarPanel1.Text = ee.Message;
  textBox9.BackColor = Color.Red ;

  }

  }
  /// <summary>
  /// //
  /// </summary>
  /// 
  //接受客户端连接的方法
  public void RecieveAccept()
  {
  try {
  while (true)
  {
  ClientSocket[ClientNumb] = ServerSocket.Accept();
  ClientSocket[ClientNumb].BeginReceive(MsgBuffer, 0, MsgBuffer.Length, 0, new AsyncCallback(RecieveCallBack), ClientSocket[ClientNumb]);
  //this.txtlink.AppendText(ClientSocket[ClientNumb].RemoteEndPoint.ToString() + " " + DateTime.Now.ToString() + " 成功连接服务器.");
  AddKhMsg(ClientSocket[ClientNumb].RemoteEndPoint.ToString() + " " + DateTime.Now.ToString() + " 成功连接服务器./n");
  ClientNumb++;
  }
  }
  catch (SocketException ex)
  {
  Console.WriteLine(ex.ToString() );

  }
  }

  //回发数据给客户端
  public void RecieveCallBack(IAsyncResult AR)
  {
  string str = string.Empty;//总的数据
  try
  {
  Socket RSocket = (Socket)AR.AsyncState;
  IPEndPoint remoEP = (IPEndPoint)RSocket.RemoteEndPoint;
  string UIp = remoEP.Address.ToString() + ":" + remoEP.Port.ToString();
  Console.WriteLine(UIp);
  int REnd = RSocket.EndReceive(AR);
   

  for (int i = 0; i < REnd; i++)
  {
  str += Convert.ToString(MsgBuffer[i], 16).PadLeft(2, '0').ToUpper().Trim();
  }
   
  }
  catch (SocketException ex)
  {
  Console.WriteLine(ex.ToString() );

  }
  textBox6.BackColor = Color.White;
  textBox8.BackColor = Color.White;
  }
连接多个客户端时就死了,请大家多多指教。