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();

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);

//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);

//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);

//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();

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

过来学习的。。。。。。。。。。。。。。。。。。。。。。

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

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.

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)
{}

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。

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

blog.csdn.net/lanwilliam
网络编程中是我原来搜集的代码，自己看吧，不贴了。

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

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>

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

以下是我们学院练习项目做的《银证转帐系统》的通信代码，跟大家分享下：
楼主给分不要吝啬哦~做得挺辛苦的。

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();
}
}

（福建师范大学软件学院）

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

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
}
}

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

你们都不要看了，如果是说socket这块，不知还有谁写的能和lumisoft.net的超级socket API比较
TCP UDP HTTP FTP SDP SIP POP3 SMTP......全都有
好好学习吧，不用贴代码占楼了，大家去下载看， 带html API 文档的，是zip包

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

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

帖子已整理完毕，大家的大码都贴到一个帖子上去了↓，此贴结贴。
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();

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

上面发了服务器端,没发客户端,现在补上!不知道写的好不好,见笑了

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

CheckForIllegalCrossThre adCalls = 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。

C#完整的通信代码（点对点，点对多，同步，异步，UDP，TCP）(2011-03-24 11:40:16)转载▼标签：杂谈分类： C#C# codenamespace UDPServer{    class Program    {        static void Main(string[] ar 二.客户端 代码 private const int portNum =13;//服务器 端口 private const string hostName = "127.0.0.1";         [STA Thread ]         static void Main( string [] args)