大家可以看看微软公布的部分.net源码，很不错的，比如 TcpListener 类的：
//------------------------------------------------------------------------------
// <copyright file="TCPListener.cs" company="Microsoft">
//
// Copyright (c) 2002 Microsoft Corporation. All rights reserved.
//
// The use and distribution terms for this software are contained in the file
// named license.txt, which can be found in the root of this distribution.
// By using this software in any fashion, you are agreeing to be bound by the
// terms of this license.
//
// You must not remove this notice, or any other, from this software.
//
// </copyright>
//------------------------------------------------------------------------------
namespace System.Net.Sockets {
using System;
using System.Net;
/// <include file='doc/TCPListener.uex' path='docs/doc[@for="TcpListener"]/*' />
/// <devdoc>
/// <para>The <see cref='System.Net.Sockets.TcpListener'/> class provide TCP services at a higher level of abstraction than the <see cref='System.Net.Sockets.Socket'/>
/// class. <see cref='System.Net.Sockets.TcpListener'/> is used to create a host process that
/// listens for connections from TCP clients.</para>
/// </devdoc>
public class TcpListener {
IPEndPoint m_ServerSocketEP;
Socket m_ServerSocket;
/// <include file='doc/TCPListener.uex' path='docs/doc[@for="TcpListener.TcpListener"]/*' />
/// <devdoc>
/// <para>
/// Initializes a new instance of the TcpListener class with the specified local
/// end point.
/// </para>
/// </devdoc>
public TcpListener(IPEndPoint localEP) {
if (localEP==null) {
throw new ArgumentNullException("localEP");
}
m_ServerSocketEP = localEP;
}
/// <include file='doc/TCPListener.uex' path='docs/doc[@for="TcpListener.TcpListener1"]/*' />
/// <devdoc>
/// <para>
/// Initializes a new instance of the TcpListener class that listens to the
/// specified IP address and port.
/// </para>
/// </devdoc>
public TcpListener(IPAddress localaddr, int port) {
if (localaddr==null) {
throw new ArgumentNullException("localaddr");
}
if (!ValidationHelper.ValidateTcpPort(port)) {
throw new ArgumentOutOfRangeException("port");
}
m_ServerSocketEP = new IPEndPoint(localaddr, port);
}
// implementation picks an address for client
/// <include file='doc/TCPListener.uex' path='docs/doc[@for="TcpListener.TcpListener2"]/*' />
/// <devdoc>
/// <para>
/// Initiailizes a new instance of the TcpListener class
/// that listens on the specified
/// port.
/// </para>
/// </devdoc>
public TcpListener(int port) {
if (!ValidationHelper.ValidateTcpPort(port)) {
throw new ArgumentOutOfRangeException("port");
}
m_ServerSocketEP = new IPEndPoint(IPAddress.Any, port);
}
/// <include file='doc/TCPListener.uex' path='docs/doc[@for="TcpListener.Server"]/*' />
/// <devdoc>
/// <para>
/// Used by the class to provide the underlying network socket.
/// </para>
/// </devdoc>
protected Socket Server {
get {
return m_ServerSocket;
}
}
/// <include file='doc/TCPListener.uex' path='docs/doc[@for="TcpListener.Active"]/*' />
/// <devdoc>
/// <para>
/// Used
/// by the class to indicate that the listener's socket has been bound to a port
/// and started listening.
/// </para>
/// </devdoc>
protected bool Active {
get {
return m_ServerSocket!=null;
}
}
/// <include file='doc/TCPListener.uex' path='docs/doc[@for="TcpListener.LocalEndpoint"]/*' />
/// <devdoc>
/// <para>
/// Gets the m_Active EndPoint for the local listener socket.
/// </para>
/// </devdoc>
public EndPoint LocalEndpoint {
get {
return (m_ServerSocket!=null) ? m_ServerSocket.LocalEndPoint : m_ServerSocketEP;
}
}
// Start/stop the listener
/// <include file='doc/TCPListener.uex' path='docs/doc[@for="TcpListener.Start"]/*' />
/// <devdoc>
/// <para>
/// Starts listening to network requests.
/// </para>
/// </devdoc>
public void Start() {
GlobalLog.Print("TCPListener::Start()");
if (m_ServerSocket!=null) {
//
// TcpListener was already started,
// ignore the failure and keep listening.
//
return;
}
//
// create a new accepting socket (it will be in blocking mode)
// then
Bind() it to the supplied IPEndPoint and Listen()
//
m_ServerSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
m_ServerSocket.Bind(m_ServerSocketEP);
m_ServerSocket.Listen((int)SocketOptionName.MaxConnections);
}
/// <include file='doc/TCPListener.uex' path='docs/doc[@for="TcpListener.Stop"]/*' />
/// <devdoc>
/// <para>
/// Closes the network connection.
/// </para>
/// </devdoc>
public void Stop() {
GlobalLog.Print("TCPListener::Stop()");
if (m_ServerSocket==null) {
//
// TcpListener was already stopped or never started,
// ignore the failure anddo
n't listen.
//
return;
}
//
// Close() the Socket and null it out so that we can reuse
// the bound end point as soon as possible
//
m_ServerSocket.Close();
m_ServerSocket = null;
}
/// <include file='doc/TCPListener.uex' path='docs/doc[@for="TcpListener.Finalize"]/*' />
~TcpListener() {
Stop();
}
// Determine if there are pending connections
/// <include file='doc/TCPListener.uex' path='docs/doc[@for="TcpListener.Pending"]/*' />
/// <devdoc>
/// <para>
/// Determine if there are pending connection requests.
/// </para>
/// </devdoc>
public bool Pending() {
if (m_ServerSocket==null) {
throw new InvalidOperationException(SR.GetString(SR.net_stopped));
}
return m_ServerSocket.Poll(0, SelectMode.SelectRead);
}
// Accept the first pending connection
/// <include file='doc/TCPListener.uex' path='docs/doc[@for="TcpListener.AcceptSocket"]/*' />
/// <devdoc>
/// <para>
/// Accepts a pending connection request.
/// </para>
/// </devdoc>
public Socket AcceptSocket() {
if (m_ServerSocket==null) {
throw new InvalidOperationException(SR.GetString(SR.net_stopped));
}
return m_ServerSocket.Accept();
}
// UEUE
/// <include file='doc/TCPListener.uex' path='docs/doc[@for="TcpListener.AcceptTcpClient"]/*' />
/// <devdoc>
/// <para>[To be supplied.]</para>
/// </devdoc>
public TcpClient AcceptTcpClient() {
if (m_ServerSocket==null) {
throw new InvalidOperationException(SR.GetString(SR.net_stopped));
}
Socket acceptedSocket = m_ServerSocket.Accept();
TcpClient returnValue = new TcpClient(acceptedSocket);
return returnValue;
}
};
// class TcpListener
} // namespace System.Net.Sockets
]
]