Programming Language | LongSheng

网页信息采集核心代码收集

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<ol class="dp-c"><li class="alt">1.通过HttpWebResponse 来获取 </li><li>public static string CheckTeamSiteUrl(string url)   </li><li class="alt">    {   </li><li>        string response = "";   </li><li class="alt">        HttpWebResponse httpResponse = null;   </li><li>   </li><li class="alt">        //assert: user have access to URL    </li><li>        try   </li><li class="alt">        {   </li><li>            HttpWebRequest httpRequest = (HttpWebRequest)WebRequest.Create(url);   </li><li class="alt">            httpRequest.Headers.Set("Pragma", "no-cache");   </li><li>   </li><li class="alt">                // request.Headers.Set("KeepAlive", "true");   </li><li>   </li><li class="alt">                httpRequest.CookieContainer = new CookieContainer();   </li><li>   </li><li class="alt">   </li><li>   </li><li class="alt">                httpRequest.Referer = url;   </li><li>   </li><li class="alt">                httpRequest.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727)";   </li><li>   </li><li class="alt">                 </li><li>   </li><li class="alt">            httpRequest.Credentials = System.Net.CredentialCache.DefaultCredentials;   </li><li>            httpResponse = (HttpWebResponse)httpRequest.GetResponse();   </li><li class="alt">               </li><li>        }   </li><li class="alt">        catch (Exception ex)   </li><li>        {   </li><li class="alt">            throw new ApplicationException("HTTP 403 Access denied, URL: " + url, ex);   </li><li>        }   </li><li class="alt">   </li><li>        //if here, the URL is correct and the user has access    </li><li class="alt">        try   </li><li>        {   </li><li class="alt">            string strEncod = httpResponse.ContentType;   </li><li>            StreamReader stream;   </li><li class="alt">            if (strEncod.ToLower().IndexOf("utf") != -1)   </li><li>            {   </li><li class="alt">                stream = new StreamReader(httpResponse.GetResponseStream(), System.Text.Encoding.UTF8);   </li><li>            }   </li><li class="alt">            else   </li><li>            {   </li><li class="alt">                stream = new StreamReader(httpResponse.GetResponseStream(), System.Text.Encoding.Default);   </li><li>            }   </li><li class="alt">              </li><li>            char[] buff = new char[4000];   </li><li class="alt">            stream.ReadBlock(buff,0,4000);   </li><li>            response = new string(buff);   </li><li class="alt">            stream.Close();   </li><li>            httpResponse.Close();   </li><li class="alt">        }   </li><li>        catch (Exception ex)   </li><li class="alt">        {   </li><li>            throw new ApplicationException("HTTP 404 Page not found, URL: " + url, ex);   </li><li class="alt">        }   </li><li>        return response;   </li><li class="alt">   </li><li>    }   </li><li class="alt">  </li><li> </li><li>2.通过 WebResponse 来获取 </li><li class="alt"> public static string getPage(String url)   </li><li>    {   </li><li class="alt">        WebResponse result = null;   </li><li>        string resultstring = "";   </li><li class="alt">        try   </li><li>        {   </li><li class="alt">            WebRequest req = WebRequest.Create(url);   </li><li>            req.Timeout = 30000;   </li><li class="alt">            result = req.GetResponse();   </li><li>            Stream ReceiveStream = result.GetResponseStream();   </li><li class="alt">   </li><li>            //read the stream into a string   </li><li class="alt">            //StreamReader sr = new StreamReader(ReceiveStream, System.Text.Encoding.UTF8);   </li><li>            string strEncod = result.ContentType;   </li><li class="alt">            StreamReader sr;   </li><li>            if (strEncod.ToLower().IndexOf("utf") != -1)   </li><li class="alt">            {   </li><li>                sr = new StreamReader(ReceiveStream, System.Text.Encoding.UTF8);   </li><li class="alt">            }   </li><li>            else   </li><li class="alt">            {   </li><li>                sr = new StreamReader(ReceiveStream, System.Text.Encoding.Default);   </li><li class="alt">            }   </li><li>            resultstring = sr.ReadToEnd();   </li><li class="alt">            js.alert(resultstring);   </li><li>            //Console.WriteLine(resultstring);   </li><li class="alt">        }   </li><li>        catch   </li><li class="alt">        {   </li><li>            throw new Exception();   </li><li class="alt">        }   </li><li>        finally   </li><li class="alt">        {   </li><li>            if (result != null)   </li><li class="alt">            {   </li><li>                result.Close();   </li><li class="alt">            }   </li><li>        }   </li><li class="alt">        return resultstring;   </li><li>    }   </li><li class="alt">  </li><li> </li><li>3.通过WebClient来获取 </li><li class="alt"> public string get(int length)   </li><li>    {   </li><li class="alt">        try   </li><li>        {   </li><li class="alt">            getEncodeing();   </li><li>            WebClient wb = new WebClient();   </li><li class="alt">            Stream response = wb.OpenRead(url);   </li><li>            StreamReader reader = new StreamReader(response, this.encoding, true, 256000);   </li><li class="alt">            char[] a = new char[length];   </li><li>            int i  = reader.Read(a,0,length);   </li><li class="alt">            reader.Close();   </li><li>            return new string(a);   </li><li class="alt">        }   </li><li>        catch (Exception e)   </li><li class="alt">        {   </li><li>            return e.Message;   </li><li class="alt">            //return null;   </li><li>        }   </li><li class="alt">    }   </li><li>    private void getEncodeing()   </li><li class="alt">    {   </li><li>        switch (this.encode)   </li><li class="alt">        {   </li><li>            case "UTF-8": encoding = Encoding.UTF8; break;   </li><li class="alt">            case "GB2312": encoding = Encoding.GetEncoding("GB2312"); break;   </li><li>            case "ASCII": encoding = Encoding.ASCII; break;   </li><li class="alt">            default: encoding = Encoding.GetEncoding(encode); break;   </li><li>        }   </li><li class="alt">    }   </li></ol>

FROM http://blog.sina.com.cn/s/blog_758087190100rfri.html

龙生 03 May 2012

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.net连接MYSQL字符串

龙生 22 Apr 2012

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C# Socket实例

public string Hello{ Response.Write("test"); Response.End9() } 客户端:2 1 using System; 2 using System.Net; 3 using System.Net.Sockets; 4 using System.Text; 5 6 public class SynchronousSocketClient { 7 8 public static void StartClient() { 9 // Data buffer for incoming data. 10 byte[] bytes = new byte[1024]; 11 12 // Connect to a remote device. 13 try { 14 // Establish the remote endpoint for the socket. 15 // This example uses port 11000 on the local computer. 16 IPHostEntry ipHostInfo = Dns.Resolve(Dns.GetHostName()) 17 IPAddress ipAddress = ipHostInfo.AddressList[0]; 18 IPEndPoint remoteEP = […]

龙生 21 Apr 2012

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c#进制转换

/// <summary>/// 十进制转换为二进制/// </summary>/// <param name="x"></param>/// <returns></returns> public static string DecToBin(string x){string z = null;int X = Convert.ToInt32(x);int i = 0;long a, b = 0;while (X > 0){a = X%2;X = X/2;b = b + a*Pow(10, i);i++;}z = Convert.ToString(b);return z;} /// <summary>/// 16进制转ASCII码/// </summary>/// <param name="hexString"></param>/// <returns></returns> public static string HexToAscii(string hexString){StringBuilder sb = new StringBuilder();for (int i = 0; i <= hexString.Length – 2; i += 2){sb.Append(Convert.ToString(Convert.ToChar(Int32.Parse(hexString.Substring(i, 2),System.Globalization.NumberStyles.HexNumber))));}return sb.ToString();} /// <summary>/// 十进制转换为八进制/// </summary>/// <param name="x"></param>/// <returns></returns> public static string DecToOtc(string x){string z = null;int X = Convert.ToInt32(x);int […]

龙生 21 Apr 2012

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深入探析c# Socket

　　最近浏览了几篇有关Socket发送消息的文章，发现大家对Socket Send方法理解有所偏差，现将自己在开发过程中对Socket的领悟写出来，以供大家参考。　　（一）架构　　基于TCP协议的Socket通信，架构类似于B/S架构，一个Socket通信服务器，多个Socket通信客户端。Socket通信服务器启动时，会建立一个侦听Socket，侦听Socket将侦听到的Socket连接传给接受Socket，然后由接受Socket完成接受、发送消息，当Socket存在异常时，断开连接。在实际开发项目中，往往要求Socket通信服务器能提供高效、稳定的服务，一般会用到以下技术：双工通信、完成端口、SAEA、池、多线程、异步等。特别是池，用的比较多，池一般包括一下几种： 1）Buffer池，用于集中管控Socket缓冲区，防止内存碎片。 2）SAEA池，用于集中管控Socket，重复利用Socket。 3）SQL池，用于分离网络服务层与数据访问层（SQL的执行效率远远低于网络层执行效率）。 4）线程池，用于从线程池中调用空闲线程执行业务逻辑，进一步提高网络层运行效率。（二）Send 　　主服务器接受Socket为一端口，客户端Socket为一端口，这两个端口通过TCP协议建立连接，通信基础系统负责管理此连接，它有两个功能：　　1）发送消息　　2）接受消息　　Socket的Send方法，并非大家想象中的从一个端口发送消息到另一个端口，它仅仅是拷贝数据到基础系统的发送缓冲区，然后由基础系统将发送缓冲区的数据到连接的另一端口。值得一说的是，这里的拷贝数据与异步发送消息的拷贝是不一样的，同步发送的拷贝，是直接拷贝数据到基础系统缓冲区，拷贝完成后返回，在拷贝的过程中，执行线程会IO等待, 此种拷贝与Socket自带的Buffer空间无关，但异步发送消息的拷贝，是将Socket自带的Buffer空间内的所有数据，拷贝到基础系统发送缓冲区，并立即返回，执行线程无需IO等待，所以异步发送在发送前必须执行SetBuffer方法，拷贝完成后，会触发你自定义回调函数ProcessSend，在ProcessSend方法中，调用SetBuffer方法，重新初始化Buffer空间。　　口说无凭，下面给个例子：　　服务器端：客户端：解释：客户端第一次发送数据：1234567890。客户端第一个接受数据：1234567890，该数据由服务端用Send同步方法发送返回。客户端第二个接受数据：1234567890，该数据由服务端用Send异步方法发送返回。以上似乎没什么异常，好，接下来，我只发送abc。客户端第一个接受数据：abc，理所当然，没什么问题。客户端第二个接受数据：abc4567890！为什么呢？应该是abc才对呀！好，现在为大家解释一下：异步发送是将其Buffer空间中所有数据拷贝到基础系统发送缓冲区，第一次拷贝1234567890到发送缓冲区，所以收到1234567890，第二次拷贝abc到发送缓冲区，替换了先前的123，所以收到abc4567890，大家明白的？源码： BufferManager

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<div>using System.Collections.Generic; using System.Net.Sockets; // This class creates a single large buffer which can be divided up // and assigned to SocketAsyncEventArgs objects for use with each // socket I/O operation. // This enables bufffers to be easily reused and guards against // fragmenting heap memory. // // The operations exposed on the BufferManager class are not thread safe. class BufferManager { int m_numBytes; // the total number of bytes controlled by the buffer pool byte[] m_buffer; // the underlying byte array maintained by the Buffer Manager Stack<int> m_freeIndexPool; // int m_currentIndex; int m_bufferSize; public BufferManager(int totalBytes, int bufferSize) { m_numBytes = totalBytes; m_currentIndex = 0; m_bufferSize = bufferSize; m_freeIndexPool = new Stack<int>(); } // Allocates buffer space used by the buffer pool public void InitBuffer() { // create one big large buffer and divide that // out to each SocketAsyncEventArg object m_buffer = new byte[m_numBytes]; } // Assigns a buffer from the buffer pool to the // specified SocketAsyncEventArgs object // // <returns>true if the buffer was successfully set, else false</returns> public bool SetBuffer(SocketAsyncEventArgs args) { if (m_freeIndexPool.Count > 0) { args.SetBuffer(m_buffer, m_freeIndexPool.Pop(), m_bufferSize); } else { if ((m_numBytes - m_bufferSize) < m_currentIndex) { return false; } args.SetBuffer(m_buffer, m_currentIndex, m_bufferSize); m_currentIndex += m_bufferSize; } return true; } // Removes the buffer from a SocketAsyncEventArg object. // This frees the buffer back to the buffer pool public void FreeBuffer(SocketAsyncEventArgs args) { m_freeIndexPool.Push(args.Offset); args.SetBuffer(null, 0, 0); } } </div>

SocketAsyncEventArgsPool

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<div>using System; using System.Collections.Generic; using System.Net.Sockets; // Represents a collection of reusable SocketAsyncEventArgs objects. class SocketAsyncEventArgsPool { Stack<SocketAsyncEventArgs> m_pool; // Initializes the object pool to the specified size // // The "capacity" parameter is the maximum number of // SocketAsyncEventArgs objects the pool can hold public SocketAsyncEventArgsPool(int capacity) { m_pool = new Stack<SocketAsyncEventArgs>(capacity); } // Add a SocketAsyncEventArg instance to the pool // //The "item" parameter is the SocketAsyncEventArgs instance // to add to the pool public void Push(SocketAsyncEventArgs item) { if (item == null) { throw new ArgumentNullException("Items added to a SocketAsyncEventArgsPool cannot be null"); } lock (m_pool) { m_pool.Push(item); } } // Removes a SocketAsyncEventArgs instance from the pool // and returns the object removed from the pool public SocketAsyncEventArgs Pop() { lock (m_pool) { return m_pool.Pop(); } } // The number of SocketAsyncEventArgs instances in the pool public int Count { get { return m_pool.Count; } } }</div>

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<div>using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Net.Sockets; class AsyncUserToken { public Socket Socket; } </div>

Server

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<div>using System; using System.Threading; using System.Net.Sockets; using System.Net; using System.Text; // Implements the connection logic for the socket server. // After accepting a connection, all data read from the client // is sent back to the client. The read and echo back to the client pattern // is continued until the client disconnects. class Server { private int m_numConnections; // the maximum number of connections the sample is designed to handle simultaneously private int m_receiveBufferSize;// buffer size to use for each socket I/O operation BufferManager m_bufferManager; // represents a large reusable set of buffers for all socket operations const int opsToPreAlloc = 2; // read, write (don't alloc buffer space for accepts) Socket listenSocket; // the socket used to listen for incoming connection requests // pool of reusable SocketAsyncEventArgs objects for write, read and accept socket operations SocketAsyncEventArgsPool m_readWritePool; int m_totalBytesRead; // counter of the total # bytes received by the server int m_numConnectedSockets; // the total number of clients connected to the server Semaphore m_maxNumberAcceptedClients; // Create an uninitialized server instance. // To start the server listening for connection requests // call the Init method followed by Start method // // <param name="numConnections">the maximum number of connections the sample is designed to handle simultaneously</param> // <param name="receiveBufferSize">buffer size to use for each socket I/O operation</param> public Server(int numConnections, int receiveBufferSize) { m_totalBytesRead = 0; m_numConnectedSockets = 0; m_numConnections = numConnections; m_receiveBufferSize = receiveBufferSize; // allocate buffers such that the maximum number of sockets can have one outstanding read and //write posted to the socket simultaneously m_bufferManager = new BufferManager(receiveBufferSize * numConnections * opsToPreAlloc, receiveBufferSize); m_readWritePool = new SocketAsyncEventArgsPool(numConnections); m_maxNumberAcceptedClients = new Semaphore(numConnections, numConnections); } // Initializes the server by preallocating reusable buffers and // context objects. These objects do not need to be preallocated // or reused, but it is done this way to illustrate how the API can // easily be used to create reusable objects to increase server performance. // public void Init() { // Allocates one large byte buffer which all I/O operations use a piece of. This gaurds // against memory fragmentation m_bufferManager.InitBuffer(); // preallocate pool of SocketAsyncEventArgs objects SocketAsyncEventArgs readWriteEventArg; for (int i = 0; i < m_numConnections; i++) { //Pre-allocate a set of reusable SocketAsyncEventArgs readWriteEventArg = new SocketAsyncEventArgs(); readWriteEventArg.Completed += new EventHandler<SocketAsyncEventArgs>(IO_Completed); readWriteEventArg.UserToken = new AsyncUserToken(); // assign a byte buffer from the buffer pool to the SocketAsyncEventArg object m_bufferManager.SetBuffer(readWriteEventArg); // add SocketAsyncEventArg to the pool m_readWritePool.Push(readWriteEventArg); } } // Starts the server such that it is listening for // incoming connection requests. // // <param name="localEndPoint">The endpoint which the server will listening // for connection requests on</param> public void Start(IPEndPoint localEndPoint) { // create the socket which listens for incoming connections listenSocket = new Socket(localEndPoint.AddressFamily, SocketType.Stream, ProtocolType.Tcp); listenSocket.Bind(localEndPoint); // start the server with a listen backlog of 100 connections listenSocket.Listen(100); // post accepts on the listening socket StartAccept(null); //Console.WriteLine("{0} connected sockets with one outstanding receive posted to each....press any key", m_outstandingReadCount); Console.WriteLine("Press any key to terminate the server process...."); Console.ReadKey(); } // Begins an operation to accept a connection request from the client // // <param name="acceptEventArg">The context object to use when issuing // the accept operation on the server's listening socket</param> public void StartAccept(SocketAsyncEventArgs acceptEventArg) { if (acceptEventArg == null) { acceptEventArg = new SocketAsyncEventArgs(); acceptEventArg.Completed += new EventHandler<SocketAsyncEventArgs>(AcceptEventArg_Completed); } else { // socket must be cleared since the context object is being reused acceptEventArg.AcceptSocket = null; } m_maxNumberAcceptedClients.WaitOne(); bool willRaiseEvent = listenSocket.AcceptAsync(acceptEventArg); if (!willRaiseEvent) { ProcessAccept(acceptEventArg); } } // This method is the callback method associated with Socket.AcceptAsync // operations and is invoked when an accept operation is complete // void AcceptEventArg_Completed(object sender, SocketAsyncEventArgs e) { ProcessAccept(e); } private void ProcessAccept(SocketAsyncEventArgs e) { Interlocked.Increment(ref m_numConnectedSockets); Console.WriteLine("Client connection accepted. There are {0} clients connected to the server", m_numConnectedSockets); // Get the socket for the accepted client connection and put it into the //ReadEventArg object user token SocketAsyncEventArgs readEventArgs = m_readWritePool.Pop(); ((AsyncUserToken)readEventArgs.UserToken).Socket = e.AcceptSocket; // As soon as the client is connected, post a receive to the connection bool willRaiseEvent = e.AcceptSocket.ReceiveAsync(readEventArgs); if (!willRaiseEvent) { ProcessReceive(readEventArgs); } // Accept the next connection request StartAccept(e); } // This method is called whenever a receive or send operation is completed on a socket // // <param name="e">SocketAsyncEventArg associated with the completed receive operation</param> void IO_Completed(object sender, SocketAsyncEventArgs e) { // determine which type of operation just completed and call the associated handler switch (e.LastOperation) { case SocketAsyncOperation.Receive: ProcessReceive(e); break; case SocketAsyncOperation.Send: ProcessSend(e); break; default: throw new ArgumentException("The last operation completed on the socket was not a receive or send"); } } // This method is invoked when an asynchronous receive operation completes. // If the remote host closed the connection, then the socket is closed. // If data was received then the data is echoed back to the client. // private void ProcessReceive(SocketAsyncEventArgs e) { // check if the remote host closed the connection AsyncUserToken token = (AsyncUserToken)e.UserToken; if (e.BytesTransferred > 0 && e.SocketError == SocketError.Success) { //increment the count of the total bytes receive by the server Interlocked.Add(ref m_totalBytesRead, e.BytesTransferred); Console.WriteLine("The server has read a total of {0} bytes", m_totalBytesRead); Int32 BytesToProcess = e.BytesTransferred; Byte[] bt = new Byte[BytesToProcess]; Buffer.BlockCopy(e.Buffer, e.Offset, bt, 0, BytesToProcess); string strReceive = Encoding.Default.GetString(bt); Send(token.Socket, bt, 0, bt.Length, 1000); Thread.Sleep(1000); //echo the data received back to the client //e.SetBuffer(e.Offset, e.BytesTransferred); bool willRaiseEvent = token.Socket.SendAsync(e); if (!willRaiseEvent) { ProcessSend(e); } } else { CloseClientSocket(e); } } public static void Send(Socket socket, byte[] buffer, int offset, int size, int timeout) { socket.SendTimeout = 0; int startTickCount = Environment.TickCount; int sent = 0; // how many bytes is already sent do { if (Environment.TickCount > startTickCount + timeout) //throw new Exception("Timeout."); try { sent += socket.Send(buffer, offset + sent, size - sent, SocketFlags.None); } catch (SocketException ex) { if (ex.SocketErrorCode == SocketError.WouldBlock || ex.SocketErrorCode == SocketError.IOPending || ex.SocketErrorCode == SocketError.NoBufferSpaceAvailable) { // socket buffer is probably full, wait and try again Thread.Sleep(30); } else throw ex; // any serious error occurr } } while (sent < size); } // This method is invoked when an asynchronous send operation completes. // The method issues another receive on the socket to read any additional // data sent from the client // // <param name="e"></param> private void ProcessSend(SocketAsyncEventArgs e) { if (e.SocketError == SocketError.Success) { //e.SetBuffer(e.Offset, 10); // done echoing data back to the client AsyncUserToken token = (AsyncUserToken)e.UserToken; // read the next block of data send from the client bool willRaiseEvent = token.Socket.ReceiveAsync(e); if (!willRaiseEvent) { ProcessReceive(e); } } else { CloseClientSocket(e); } } private void CloseClientSocket(SocketAsyncEventArgs e) { AsyncUserToken token = e.UserToken as AsyncUserToken; // close the socket associated with the client try { token.Socket.Shutdown(SocketShutdown.Send); } // throws if client process has already closed catch (Exception) { } token.Socket.Close(); // decrement the counter keeping track of the total number of clients connected to the server Interlocked.Decrement(ref m_numConnectedSockets); m_maxNumberAcceptedClients.Release(); Console.WriteLine("A client has been disconnected from the server. There are {0} clients connected to the server", m_numConnectedSockets); // Free the SocketAsyncEventArg so they can be reused by another client m_readWritePool.Push(e); } }</div>

Program

1

<div>using System; using System.Net; using System.Collections.Generic; using System.IO; class Program { static void Main(string[] args) { IPEndPoint iep = new IPEndPoint(IPAddress.Parse("10.1.20.6"), 1333); Server objServer = new Server(1000, 10); objServer.Init(); objServer.Start(iep); } } </div>

http://www.cnblogs.com/tianzhiliang/archive/2010/09/08/1821623.html

龙生 21 Apr 2012

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C#的Socket程序（TCP）

其实只要用到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 serverprivate void btn_startServer_Click(object sender, EventArgs e){//this.btn_startServer.Enabled = false;Thread _createServer = new Thread(new ThreadStart(WaitForConnect));_createServer.Start();}//wait all connectionsprivate 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 […]

龙生 21 Apr 2012

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LINQ&EF任我行（二）--LinQ to Object (转)

LinQ to Objects是LinQ家庭的核心，其它的LinQ也使用了与LinQ to Objects相同的查询句法。最终编译器都是把LinQ句法翻译成扩展方法的链式表达式，同时把扩展方法中的lambda表达式转换成匿名类中的匿名方法，然后再把查询表达式编译成MSIL。 LinQ to SQL、LinQ to DataSets、LinQ to Entities和LinQ to XML则不是把查询表达式转换成MSIL，而是把查询表达式树转换成相应的特定查询语言。LinQ to SQL会生成T-SQL，LinQ to Entities会生成eSQL，LinQ to XML会生成XPath语句等。 LinQ标准查询操作符列表《图1》在VS2008及以后的版本中提供了LinQ的查询样例程序。 \Programe Files\Microsoft Visual Studio 2008(10.0 VS2010)\Samples\1033文件夹下有个压缩包CSharpSamples.zip，解压它，继续打开其中的文件夹 .\LinqSamples\SampleQueries\SampleQueries.sln，打开此解决方案，运行该项目，界面如下《图2》在左边选择示例，右侧上方会出现相应的LinQ代码，右侧下方会出现代码的运行结果。通过这个样例程序，我们可以学习LinQ的各种用法。下面我们来学习LinQ常用操作符一、筛选操作符Where 根据谓词对源序列的内容进行筛选，类似于SQL中的where子句。 1.简单where表达式使用扩展方法 var query1 = CustomerList.Where(c => c.Country == “USA”); 使用查询表达式语法 query1 = from c in CustomerList where c.Country == “USA” select c; 使用扩展方法需要向where方法中传入lambda表达式。 2.复合where表达式所谓的复合where表达式就是使用&&或||操作符对数据进行筛选使用扩展方法 var query2 = CustomerList.Where(c => c.Country == “USA” && c.Orders.Any()); 使用查询表达式语法 query2 = from c in CustomerList where c.Country == “USA” […]

龙生 18 Apr 2012

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ASP内置对象 Request对象

集合 Request.ClientCertificate(key[SubField])所有客户证书的信息的集合。对于Key，该集合具有如下的关键字： Subject证书的主题。包含所有关于证书收据的信息。能和所有的子域后缀一起使用。 Issuer证书的发行人。包含所有关于证书验证的信息。除了CN外，能和所有的子域后缀一起使用。 VadidFrom证书发行的日期。使用VBScript格式。 ValidUntil该证书不在有效的时间。 SerialNumber包含该证书的序列号。 Certificate包含整个证书内容的二进制流，使用ASN.1格式。对于SubField，Subject和Issuer关键字可以具有如下的子域后缀：（比如：SubjectOU或IssuerL） C起源国家。 O公司或组织名称。 OU组织单元。 CN用户的常规名称。 L局部。 S州（或省）。 T个人或公司的标题。 GN给定名称。 I初始。当文件cervbs.inc(VBScript使用)或cerjavas.inc(Jscript使用)通过使用#INCLUDE导向包含在你的Active Server Page里时，下面两个标志可以使用： ceCertPresent指明客户证书是否存在，其值为TRUE或FALSE。 ceUnrecongnizedIssure指明在该链表中的最后的证书的发行者是否未知，其值为TRUE或FALSE。 Request.Cookies(Cookie[(key).Attribute]) Cookie的集合。允许获得浏览器的Cookie。Cookie指明返回那一个Cookie。Key用于从Cookie字典中返回具有某一关键字的Cookie值。对于Attribute，你能使用属性HasKeys来确定某一Cookie是否具有子关键字。HasKeys的值为TRUE或FALSE。 Request.Form(Parameter)[(Index).Count] 填写在HTML的表单中所有的数据的集合。Parameter是在HTML表单中某一元素的名称。当某一参数具有不止一个值（比如，当在<SELECT>中使用MULTIPLE属性时）时，使用Index。当某一参数具有多值时，Count指明多值个数。 Request.QueryString(Varible)[(Index).Count] 查询字符串的所有值的集合。Varible是在查询字符串某一变量的名称。当某一变量具有多于一个值时，使用Index。当某一参数具有多值时，Count指明值的个数。 Request.ServerVaribles(Server Environment Variable) 环境变量的集合。允许读取HTTP头。你可以通过使用HTTP_前缀来读取任何头信息。比如，HTTP_USER_AGENT接受客户代理HTTP头（浏览器类型）。除此外，你可以使用下表所示的变量获得任何环境信息。 ALL_HTTP客户端发送的所有HTTP标头，他的结果都有前缀HTTP_。 ALL_RAW客户端发送的所有HTTP标头,其结果和客户端发送时一样，没有前缀HTTP_ APPL_MD_PATH应用程序的元数据库路径。 APPL_PHYSICAL_PATH与应用程序元数据库路径相应的物理路径。 AUTH_PASSWORD当使用基本验证模式时，客户在密码对话框中输入的密码。 AUTH_TYPE这是用户访问受保护的脚本时，服务器用于检验用户的验证方法。 AUTH_USER代验证的用户名。 CERT_COOKIE唯一的客户证书ID号。 CERT_FLAG客户证书标志，如有客户端证书，则bit0为0。如果客户端证书验证无效，bit1被设置为1。 CERT_ISSUER用户证书中的发行者字段。 CERT_KEYSIZE安全套接字层连接关键字的位数，如128。 CERT_SECRETKEYSIZE服务器验证私人关键字的位数。如1024。 CERT_SERIALNUMBER客户证书的序列号字段。 CERT_SERVER_ISSUER服务器证书的发行者字段 CERT_SERVER_SUBJECT服务器证书的主题字段。 CERT_SUBJECT客户端证书的主题字段。 CONTENT_LENGTH客户端发出内容的长度。 CONTENT_TYPE客户发送的form内容或HTTP PUT的数据类型。 GATEWAY_INTERFACE服务器使用的网关界面。 HTTPS如果请求穿过安全通道（SSL），则返回ON。如果请求来自非安全通道，则返回OFF。 HTTPS_KEYSIZE安全套接字层连接关键字的位数，如128。 HTTPS_SECRETKEYSIZE服务器验证私人关键字的位数。如1024。 HTTPS_SERVER_ISSUER服务器证书的发行者字段。 HTTPS_SERVER_SUBJECT服务器证书的主题字段。 INSTANCE_IDIIS实例的ID号。 INSTANCE_META_PATH响应请求的IIS实例的元数据库路径。 LOCAL_ADDR返回接受请求的服务器地址。 LOGON_USER用户登录Windows NT的帐号 PATH_INFO客户端提供的路径信息。 PATH_TRANSLATED通过由虚拟至物理的映射后得到的路径。 QUERY_STRING查询字符串内容。 REMOTE_ADDR发出请求的远程主机的IP地址。 REMOTE_HOST发出请求的远程主机名称。 REQUEST_METHOD提出请求的方法。比如GET、HEAD、POST等等。 SCRIPT_NAME执行脚本的名称。 SERVER_NAME服务器的主机名、DNS地址或IP地址。 SERVER_PORT接受请求的服务器端口号。 SERVER_PORT_SECURE如果接受请求的服务器端口为安全端口时，则为1，否则为0。 SERVER_PROTOCOL服务器使用的协议的名称和版本。 SERVER_SOFTWARE应答请求并运行网关的服务器软件的名称和版本。 URL提供URL的基本部分。　方法 Request.BinaryRead(Count) 接收一个HTML表单的未经过处理的内容。当调用此方法时，Count指明要接收多少字节。在调用此方法后，Count指明实际上接收到多少个字节。属性 Request.TotalBytes 查询体的长度，以字节为单位。

龙生 11 Apr 2012

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清除页面缓存

当使用ASP进行Web编程时，你发现确实修改了程序代码，确认没有改错，却发现输出的Webyemi8an没有变化，这就是服务端将此ASP文件加入了页面缓存。清楚页面缓存有一下几种方法； 1.在ASP页面首部加入一下代码： Response.Buffer=True Response.ExpiresAbsolute=Now()-1 Response.Expires=0 Response.CacheControl=“no-cache” Response.AddHeader “Pragma”，“no-Cache” 2.在HTML代码中加入下面的代码，不过这些代码似乎不能解决刷新无效的问题，因为这些代码只是针对客户端的页面缓存而已，只具有清楚客户端的页面缓存的功能。 <HEAD> <META HTTP-EQUIV="Pragma" CONTENT="no-cache"> <META HTTP-EQUIV="Cache-Control" CONTENT="no-cache"> <META HTTP-EQUIV="Expires" CONTENT="no-cache"> </HEAD> 3.如果一个ASP文件是url.asp,那么在访问的时候，脚本链接应该为： <input type="button" onclick="window.location.href=’url.asp?’+Math.random()" value="提交"/>

龙生 11 Apr 2012

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ScriptManager.RegisterStartupScript失效的解决方案

今天在项目中一个页面使用 System.Web.UI.ScriptManager.RegisterStartupScript(this, GetType(), "js", "alert('OK');", true);的时候发现没用，检查发现脚本没用注册到页面， check页面发现了问题，<form method="post"> 没用ruanat，更详细的信息请参看MSDN关于这个方法参数的介绍

龙生 11 Apr 2012

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