使用 Socket 类向 HTTP 服务器发送数据和接收响应。

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

public class GetSocket
{
private static Socket ConnectSocket(string server, int port)
{
Socket s = null;
IPHostEntry hostEntry = null;

// Get host related information.
hostEntry = Dns.GetHostEntry(server);

// Loop through the AddressList to obtain the supported AddressFamily. This is to avoid
// an exception that occurs when the host IP Address is not compatible with the address family
// (typical in the IPv6 case).
foreach(IPAddress address in hostEntry.AddressList)
{
IPEndPoint ipe = new IPEndPoint(address, port);
Socket tempSocket =
new Socket(ipe.AddressFamily, SocketType.Stream, ProtocolType.Tcp);

tempSocket.Connect(ipe);

if(tempSocket.Connected)
{
s = tempSocket;
break;
}
else
{
continue;
}
}
return s;
}

// This method requests the home page content for the specified server.
private static string SocketSendReceive(string server, int port)
{
string request = "GET / HTTP/1.1\r\nHost: " + server +
"\r\nConnection: Close\r\n\r\n";
Byte[] bytesSent = Encoding.ASCII.GetBytes(request);
Byte[] bytesReceived = new Byte[256];

// Create a socket connection with the specified server and port.
Socket s = ConnectSocket(server, port);

if (s == null)
return ("Connection failed");

// Send request to the server.
s.Send(bytesSent, bytesSent.Length, 0);

// Receive the server home page content.
int bytes = 0;
string page = "Default HTML page on " + server + ":\r\n";

// The following will block until te page is transmitted.
do {
bytes = s.Receive(bytesReceived, bytesReceived.Length, 0);
page = page + Encoding.ASCII.GetString(bytesReceived, 0, bytes);
}
while (bytes > 0);

return page;
}

public static void Main(string[] args)
{
string host;
int port = 80;

if (args.Length == 0)
// If no server name is passed as argument to this program,
// use the current host name as the default.
host = Dns.GetHostName();
else
host = args[0];

string result = SocketSendReceive(host, port);
Console.WriteLine(result);
}
}