学习C#时，经常会遇到Web服务器功能的程序设计问题，这里将介绍C#实现Web服务器功能的程序设计问题的解决方法。

C#实现Web服务器功能的程序设计

根据HTTP协议的作用原理，实现GET请求的Web服务器程序的方法如下：

创建TcpListener类对象，监听某端口（任意输入闲置端口 如：8080 ）。等待、接受客户机连接到该端口，得到与客户机连接的socket;从与socket关联的输入流中读取一行客户机提交的请求信息，请求信息的格式 为：GET 路径/文件名 HTTP/1.0。从请求信息中获取请求类型。如果请求类型是GET，则从请求信息中获取所访问的HTML文件名。没有HTML文件名时，则以 index.html作为文件名；

如果HTML文件存在，则打开HTML文件，把HTTP头信息和HTML文件内容通过socket传回给Web浏览器，然后关闭文件。否则发送错误信息给Web浏览器；关闭与相应Web浏览器连接的socket字。

C#实现Web服务器功能的代码如下：

    using System;        using System.IO;        using System.Net;        using System.Net.Sockets;        using System.Text;        using System.Threading ;               class MyWebServer        {               private TcpListener myListener ;        private int port = 8080 ; // 选者任何闲置端口               //开始兼听端口        //同时启动一个兼听进程        public MyWebServer()        {        try        {        //开始兼听端口        myListener = new TcpListener(port) ;        myListener.Start();        Console.WriteLine("Web Server Running... Press ^C to Stop...");        //同时启动一个兼听进程 ''StartListen''        Thread th = new Thread(new ThreadStart(StartListen));        th.Start() ;               }        catch(Exception e)        {        Console.WriteLine("兼听端口时发生错误 :" +e.ToString());        }        }        public void SendHeader(string sHttpVersion, string sMIMEHeader,       int iTotBytes, string sStatusCode, ref Socket mySocket)        {               String sBuffer = "";               if (sMIMEHeader.Length == 0 )        {        sMIMEHeader = "text/html"; // 默认 text/html        }               sBuffersBuffer = sBuffer + sHttpVersion + sStatusCode + "\r\n";        sBuffersBuffer = sBuffer + "Server: cx1193719-b\r\n";        sBuffersBuffer = sBuffer + "Content-Type: " + sMIMEHeader + "\r\n";        sBuffersBuffer = sBuffer + "Accept-Ranges: bytes\r\n";        sBuffersBuffer = sBuffer + "Content-Length: " + iTotBytes + "\r\n\r\n";               Byte[] bSendData = Encoding.ASCII.GetBytes(sBuffer);               SendToBrowser( bSendData, ref mySocket);               Console.WriteLine("Total Bytes : " + iTotBytes.ToString());               }               public void SendToBrowser(String sData, ref Socket mySocket)        {        SendToBrowser (Encoding.ASCII.GetBytes(sData), ref mySocket);        }               public void SendToBrowser(Byte[] bSendData, ref Socket mySocket)        {        int numBytes = 0;               try        {        if (mySocket.Connected)        {        if (( numBytes = mySocket.Send(bSendData, bSendData.Length,0)) == -1)        Console.WriteLine("Socket Error cannot Send Packet");        else        {        Console.WriteLine("No. of bytes send {0}" , numBytes);        }        }        else        Console.WriteLine("连接失败....");        }        catch (Exception e)        {        Console.WriteLine("发生错误 : {0} ", e );               }        }        public static void Main()        {        MyWebServer MWS = new MyWebServer();        }        public void StartListen()        {               int iStartPos = 0;        String sRequest;        String sDirName;        String sRequestedFile;        String sErrorMessage;        String sLocalDir;               String sMyWebServerRoot = "E:\\MyWebServerRoot\\"; //设置你的虚拟目录               String sPhysicalFilePath = "";        String sFormattedMessage = "";        String sResponse = "";               while(true)        {        //接受新连接        Socket mySocket = myListener.AcceptSocket() ;               Console.WriteLine ("Socket Type " +mySocket.SocketType );        if(mySocket.Connected)        {        Console.WriteLine("\nClient Connected!!\n=\nCLient IP {0}\n",mySocket.RemoteEndPoint) ;               Byte[] bReceive = new Byte[1024] ;        int i = mySocket.Receive(bReceive,bReceive.Length,0) ;               //转换成字符串类型        string sBuffer = Encoding.ASCII.GetString(bReceive);                      //只处理"get"请求类型        if (sBuffer.Substring(0,3) != "GET" )        {        Console.WriteLine("只处理get请求类型..");        mySocket.Close();        return;        }               // 查找 "HTTP" 的位置        iStartPos = sBuffer.IndexOf("HTTP",1);               string sHttpVersion = sBuffer.Substring(iStartPos,8);               // 得到请求类型和文件目录文件名        sRequest = sBuffer.Substring(0,iStartPos - 1);               sRequest.Replace("\\","/");               //如果结尾不是文件名也不是以"/"结尾则加"/"        if ((sRequest.IndexOf(".") <1) && (!sRequest.EndsWith("/")))        {        sRequestsRequest = sRequest + "/";        }               //得带请求文件名        iStartPos = sRequest.LastIndexOf("/") + 1;        sRequestsRequestedFile = sRequest.Substring(iStartPos);               //得到请求文件目录        sDirName = sRequest.Substring(sRequest.IndexOf("/"), sRequest.LastIndexOf("/")-3);               //获取虚拟目录物理路径        sLocalDir = sMyWebServerRoot;               Console.WriteLine("请求文件目录 : " + sLocalDir);               if (sLocalDir.Length == 0 )        {        sErrorMessage = "<H2>Error!! Requested Directory does not exists</H2><Br>";        SendHeader(sHttpVersion, "", sErrorMessage.Length, " 404 Not Found", ref mySocket);        SendToBrowser(sErrorMessage, ref mySocket);        mySocket.Close();        continue;        }               if (sRequestedFile.Length == 0 )        {        // 取得请求文件名        sRequestedFile = "index.html";        }                      String sMimeType = "text/html";               sPhysicalFilePath = sLocalDir + sRequestedFile;        Console.WriteLine("请求文件: " + sPhysicalFilePath);               if (File.Exists(sPhysicalFilePath) == false)        {               sErrorMessage = "<H2>404 Error! File Does Not Exists...</H2>";        SendHeader(sHttpVersion, "", sErrorMessage.Length, " 404 Not Found", ref mySocket);        SendToBrowser( sErrorMessage, ref mySocket);               Console.WriteLine(sFormattedMessage);        }               else        {        int iTotBytes=0;               sResponse ="";               FileStream fs = new FileStream(sPhysicalFilePath,       FileMode.Open, FileAccess.Read, FileShare.Read);               BinaryReader reader = new BinaryReader(fs);        byte[] bytes = new byte[fs.Length];        int read;        while((read = reader.Read(bytes, 0, bytes.Length)) != 0)        {        sResponsesResponse = sResponse + Encoding.ASCII.GetString(bytes,0,read);               iTotBytesiTotBytes = iTotBytes + read;               }        reader.Close();        fs.Close();               SendHeader(sHttpVersion, sMimeType, iTotBytes, " 200 OK", ref mySocket);        SendToBrowser(bytes, ref mySocket);        //mySocket.Send(bytes, bytes.Length,0);        }        mySocket.Close();        }        }        }        }        }