使用.NET访问Internet(5) Paul_Ni（原作）

同步客户端套接字示例

下面的示例程序创建一个连接到服务器的客户端。该客户端是用同步套接字生成的，因此挂起客户端应用程序的执行，直到服务器返回响应为止。该应用程序将字符串发送到服务器，然后在控制台显示该服务器返回的字符串。 [C#]using System;using System.Net;using System.Net.Sockets;using System.Text; public class SynchronousSocketClient {   public static void StartClient() {    // Data buffer for incoming data.    byte[] bytes = new byte[1024];     // Connect to a remote device.    try {      // Establish the remote endpoint for the socket.      //    The name of the      //   remote device is "host.contoso.com".      IPHostEntry ipHostInfo = Dns.Resolve("host.contoso.com");      IPAddress ipAddress = ipHostInfo.AddressList[0];      IPEndPoint remoteEP = new IPEndPoint(ipAddress,11000);       // Create a TCP/IP  socket.      Socket sender = new Socket(AddressFamily.InterNetwork,         SocketType.Stream, ProtocolType.Tcp );       // Connect the socket to the remote endpoint. Catch any errors.      try {        sender.Connect(remoteEP);         Console.WriteLine("Socket connected to {0}",          sender.RemoteEndPoint.ToString());         // Encode the data string into a byte array.        byte[] msg = Encoding.ASCII.GetBytes("This is a test<EOF>");         // Send the data through the  socket.        int bytesSent = sender.Send(msg);         // Receive the response from the remote device.        int bytesRec = sender.Receive(bytes);        Console.WriteLine("Echoed test = {0}",          Encoding.ASCII.GetString(bytes,0,bytesRec));         // Release the socket.        sender.Shutdown(SocketShutdown.Both);        sender.Close();              } catch (ArgumentNullException ane) {        Console.WriteLine("ArgumentNullException : {0}",ane.ToString());      } catch (SocketException se) {        Console.WriteLine("SocketException : {0}",se.ToString());      } catch (Exception e) {        Console.WriteLine("Unexpected exception : {0}", e.ToString());      }     } catch (Exception e) {      Console.WriteLine( e.ToString());    }  }    public static int Main(String[] args) {    StartClient();    return 0;  }}

同步服务器套接字示例

下面的示例程序创建一个接收来自客户端的连接请求的服务器。该服务器是用同步套接字生成的，因此在等待来自客户端的连接时不挂起服务器应用程序的执行。该应用程序接收来自客户端的字符串，在控制台显示该字符串，然后将该字符串回显到客户端。来自客户端的字符串必须包含字符串“<EOF>”，以发出表示消息结尾的信号。 [C#]using System;using System.Net;using System.Net.Sockets;using System.Text; public class SynchronousSocketListener {    // Incoming data from the client.  public static string data = null;   public static void StartListening() {    // Data buffer for incoming data.    byte[] bytes = new Byte[1024];     // Establish the local endpoint for the  socket.    //  Dns.GetHostName returns the name of the     // host running the application.    IPHostEntry ipHostInfo = Dns.Resolve(Dns.GetHostName());    IPAddress ipAddress = ipHostInfo.AddressList[0];    IPEndPoint localEndPoint = new IPEndPoint(ipAddress, 11000);     // 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(10);       // Start listening for connections.      while (true) {        Console.WriteLine("Waiting for a connection...");        // Program is suspended while waiting for an incoming connection.        Socket handler = listener.Aclearcase/" target="_blank" >ccept();        data = null;         // An incoming connection needs to be processed.        while (true) {          bytes = new byte[1024];          int bytesRec = handler.Receive(bytes);          data += Encoding.ASCII.GetString(bytes,0,bytesRec);          if (data.IndexOf("<EOF>") > -1) {            break;          }        }         // Show the data on the console.        Console.WriteLine( "Text received : {0}", data);         // Echo the data back to the client.        byte[] msg = Encoding.ASCII.GetBytes(data);         handler.Send(msg);        handler.Shutdown(SocketShutdown.Both);        handler.Close();      }          } catch (Exception e) {      Console.WriteLine(e.ToString());    }     Console.WriteLine("\nHit enter to continue...");    Console.Read();      }   public static int Main(String[] args) {    StartListening();    return 0;  }}

异步客户端套接字示例

下面的示例程序创建一个连接到服务器的客户端。该客户端是用异步套接字生成的，因此在等待服务器返回响应时不挂起客户端应用程序的执行。该应用程序将字符串发送到服务器，然后在控制台显示该服务器返回的字符串。 [C#]using System;using System.Net;using System.Net.Sockets;using System.Threading;using System.Text; // State object for receiving data from remote device.public class StateObject {  public Socket workSocket = null;              // Client socket.  public const int BufferSize = 256;            // Size of receive buffer.  public byte[] buffer = new byte[BufferSize];  // Receive buffer.  public StringBuilder sb = new StringBuilder();// Received data string.} public class AsynchronousClient {  // The port number for the remote device.  private const int port = 11000;   // ManualResetEvent instances signal completion.  private static ManualResetEvent connectDone =     new ManualResetEvent(false);  private static ManualResetEvent sendDone =     new ManualResetEvent(false);  private static ManualResetEvent receiveDone =     new ManualResetEvent(false);   // The response from the remote device.  private static String response = String.Empty;   private static void StartClient() {    // Connect to a remote device.    try {      // Establish the remote endpoint for the socket.      // "host.contoso.com" is the name of the      // remote device.      IPHostEntry ipHostInfo = Dns.Resolve("host.contoso.com");      IPAddress ipAddress = ipHostInfo.AddressList[0];      IPEndPoint remoteEP = new IPEndPoint(ipAddress, port);       //  Create a TCP/IP  socket.      Socket client = new Socket(AddressFamily.InterNetwork,        SocketType.Stream, ProtocolType.Tcp);       // Connect to the remote endpoint.      client.BeginConnect( remoteEP,         new AsyncCallback(ConnectCallback), client);      connectDone.WaitOne();       // Send test data to the remote device.      Send(client,"This is a test<EOF>");      sendDone.WaitOne();       // Receive the response from the remote device.      Receive(client);      receiveDone.WaitOne();       // Write the response to the console.      Console.WriteLine("Response received : {0}", response);       // Release the socket.      client.Shutdown(SocketShutdown.Both);      client.Close();          } catch (Exception e) {      Console.WriteLine(e.ToString());    }  }   private static void ConnectCallback(IAsyncResult ar) {    try {      // Retrieve the socket from the state object.      Socket client = (Socket) ar.AsyncState;       // Complete the connection.      client.EndConnect(ar);       Console.WriteLine("Socket connected to {0}",        client.RemoteEndPoint.ToString());       // Signal that the connection has been made.      connectDone.Set();    } catch (Exception e) {      Console.WriteLine(e.ToString());    }  }   private static void Receive(Socket client) {    try {      // Create the state object.      StateObject state = new StateObject();      state.workSocket = client;       // Begin receiving the data from the remote device.      client.BeginReceive( state.buffer, 0, StateObject.BufferSize, 0,        new AsyncCallback(ReceiveCallback), state);    } catch (Exception e) {      Console.WriteLine(e.ToString());    }  }   private static void ReceiveCallback( IAsyncResult ar ) {    try {      // Retrieve the state object and the client socket       // from the async state object.      StateObject state = (StateObject) ar.AsyncState;      Socket client = state.workSocket;       // Read data from the remote device.      int bytesRead = client.EndReceive(ar);       if (bytesRead > 0) {        // There might be more data, so store the data received so far.      state.sb.Append(Encoding.ASCII.GetString(state.buffer,0,bytesRead));         //  Get the rest of the data.        client.BeginReceive(state.buffer,0,StateObject.BufferSize,0,          new AsyncCallback(ReceiveCallback), state);      } else {        // All the data has arrived; put it in response.        if (state.sb.Length > 1) {          response = state.sb.ToString();        }        // Signal that all bytes have been received.        receiveDone.Set();      }    } catch (Exception e) {      Console.WriteLine(e.ToString());    }  }   private static void Send(Socket client, String data) {    // Convert the string data to byte data using ASCII encoding.    byte[] byteData = Encoding.ASCII.GetBytes(data);     // Begin sending the data to the remote device.    client.BeginSend(byteData, 0, byteData.Length, 0,      new AsyncCallback(SendCallback), client);  }   private static void SendCallback(IAsyncResult ar) {    try {      // Retrieve the socket from the state object.      Socket client = (Socket) ar.AsyncState;       // Complete sending the data to the remote device.      int bytesSent = client.EndSend(ar);      Console.WriteLine("Sent {0} bytes to server.", bytesSent);       // Signal that all bytes have been sent.      sendDone.Set();    } catch (Exception e) {      Console.WriteLine(e.ToString());    }  }    public static int Main(String[] args) {    StartClient();    return 0;  }}

原文转自：http://www.ltesting.net