详解C# Socket异步通信实例
TCPServer
1、使用的通讯通道:socket
2、用到的基本功能:
①Bind,
②Listen,
③BeginAccept
④EndAccept
⑤BeginReceive
⑥EndReceive
3、函数参数说明
Socket listener = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
新建socket所使用的参数均为系统预定义的量,直接选取使用。
listener.Bind(localEndPoint);
localEndPoint 表示一个定义完整的终端,包括IP和端口信息。
//new IPEndPoint(IPAddress,port) //IPAdress.Parse("192.168.1.3") listener.Listen(100);
监听
listener.BeginAccept( new AsyncCallback(AcceptCallback), listener);
AsyncCallback(AcceptCallback),一旦连接上后的回调函数为AcceptCallback。当系统调用这个函数时,自动赋予的输入参数为IAsyncResoult类型变量ar。
listener,连接行为的容器。
Socket handler = listener.EndAccept(ar);
完成连接,返回此时的socket通道。
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReadCallback), state);
接收的字节,0,字节长度,0,接收时调用的回调函数,接收行为的容器。
========
容器的结构类型为:
public class StateObject { // Client socket. public Socket workSocket = null; // Size of receive buffer. public const int BufferSize = 1024; // Receive buffer. public byte[] buffer = new byte[BufferSize]; // Received data string. public StringBuilder sb = new StringBuilder(); }
容器至少为一个socket类型。
===============
// Read data from the client socket. int bytesRead = handler.EndReceive(ar);
完成一次连接。数据存储在state.buffer里,bytesRead为读取的长度。
handler.BeginSend(byteData, 0, byteData.Length, 0, new AsyncCallback(SendCallback), handler);
发送数据byteData,回调函数SendCallback。容器handler
int bytesSent = handler.EndSend(ar);
发送完毕,bytesSent发送字节数。
4 程序结构
主程序:
byte[] bytes = new Byte[1024]; IPAddress ipAddress = IPAddress.Parse("192.168.1.104"); IPEndPoint localEndPoint = new IPEndPoint(ipAddress, 11000); // 生成一个TCP的socket Socket listener = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); listener.Bind(localEndPoint); listener.Listen(100); while (true) { // Set the event to nonsignaled state. allDone.Reset(); //开启异步监听socket Console.WriteLine("Waiting for a connection"); listener.BeginAccept( new AsyncCallback(AcceptCallback), listener); // 让程序等待,直到连接任务完成。在AcceptCallback里的适当位置放置allDone.Set()语句. allDone.WaitOne(); } Console.WriteLine("\nPress ENTER to continue"); Console.Read();
连接行为回调函数AcceptCallback:
public static void AcceptCallback(IAsyncResult ar) { //添加此命令,让主线程继续. allDone.Set(); // 获取客户请求的socket Socket listener = (Socket)ar.AsyncState; Socket handler = listener.EndAccept(ar); // 造一个容器,并用于接收命令. StateObject state = new StateObject(); state.workSocket = handler; handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReadCallback), state); }
读取行为的回调函数ReadCallback:
public static void ReadCallback(IAsyncResult ar) { String content = String.Empty; // 从异步state对象中获取state和socket对象. StateObject state = (StateObject)ar.AsyncState; Socket handler = state.workSocket; // 从客户socket读取数据. int bytesRead = handler.EndReceive(ar); if (bytesRead > 0) { // 如果接收到数据,则存起来 state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, bytesRead)); // 检查是否有结束标记,如果没有则继续读取 content = state.sb.ToString(); if (content.IndexOf("<EOF>") > -1) { //所有数据读取完毕. Console.WriteLine("Read {0} bytes from socket. \n Data : {1}", content.Length, content); // 给客户端响应. Send(handler, content); } else { // 接收未完成,继续接收. handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReadCallback), state); } } }
发送消息给客户端:
private static void Send(Socket handler, String data) { // 消息格式转换. byte[] byteData = Encoding.ASCII.GetBytes(data); // 开始发送数据给远程目标. handler.BeginSend(byteData, 0, byteData.Length, 0, new AsyncCallback(SendCallback), handler); } private static void SendCallback(IAsyncResult ar) { // 从state对象获取socket. Socket handler = (Socket)ar.AsyncState; //完成数据发送 int bytesSent = handler.EndSend(ar); Console.WriteLine("Sent {0} bytes to client.", bytesSent); handler.Shutdown(SocketShutdown.Both); handler.Close(); }
在各种行为的回调函数中,所对应的socket都从输入参数的AsyncState属性获得。使用(Socket)或者(StateObject)进行强制转换。BeginReceive函数使用的容器为state,因为它需要存放传送的数据。
而其余接收或发送函数的容器为socket也可。
完整代码
using System; using System.Net; using System.Net.Sockets; using System.Text; using System.Threading; // State object for reading client data asynchronously public class StateObject { // Client socket. public Socket workSocket = null; // Size of receive buffer. public const int BufferSize = ; // Receive buffer. public byte[] buffer = new byte[BufferSize]; // Received data string. public StringBuilder sb = new StringBuilder(); } public class AsynchronousSocketListener { // Thread signal. public static ManualResetEvent allDone = new ManualResetEvent(false); public AsynchronousSocketListener() { } public static void StartListening() { // Data buffer for incoming data. byte[] bytes = new Byte[]; // Establish the local endpoint for the socket. // The DNS name of the computer // running the listener is "host.contoso.com". //IPHostEntry ipHostInfo = Dns.Resolve(Dns.GetHostName()); IPAddress ipAddress = IPAddress.Parse("..."); IPEndPoint localEndPoint = new IPEndPoint(ipAddress, ); // 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(); while (true) { // Set the event to nonsignaled state. allDone.Reset(); // Start an asynchronous socket to listen for connections. Console.WriteLine("Waiting for a connection"); listener.BeginAccept( new AsyncCallback(AcceptCallback), listener); // Wait until a connection is made before continuing. allDone.WaitOne(); } } catch (Exception e) { Console.WriteLine(e.ToString()); } Console.WriteLine("\nPress ENTER to continue"); Console.Read(); } public static void AcceptCallback(IAsyncResult ar) { // Signal the main thread to continue. allDone.Set(); // Get the socket that handles the client request. Socket listener = (Socket)ar.AsyncState; Socket handler = listener.EndAccept(ar); // Create the state object. StateObject state = new StateObject(); state.workSocket = handler; handler.BeginReceive(state.buffer, , StateObject.BufferSize, , new AsyncCallback(ReadCallback), state); } public static void ReadCallback(IAsyncResult ar) { String content = String.Empty; // Retrieve the state object and the handler socket // from the asynchronous state object. StateObject state = (StateObject)ar.AsyncState; Socket handler = state.workSocket; // Read data from the client socket. int bytesRead = handler.EndReceive(ar); if (bytesRead > ) { // There might be more data, so store the data received so far. state.sb.Append(Encoding.ASCII.GetString( state.buffer, , bytesRead)); // Check for end-of-file tag. If it is not there, read // more data. content = state.sb.ToString(); if (content.IndexOf("<EOF>") > -) { // All the data has been read from the // client. Display it on the console. Console.WriteLine("Read {} bytes from socket. \n Data : {}",content.Length, content); // Echo the data back to the client. Send(handler, content); } else { // Not all data received. Get more. handler.BeginReceive(state.buffer, , StateObject.BufferSize, , new AsyncCallback(ReadCallback), state); } } } private static void Send(Socket handler, 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. handler.BeginSend(byteData, , byteData.Length, , new AsyncCallback(SendCallback), handler); } private static void SendCallback(IAsyncResult ar) { try { // Retrieve the socket from the state object. Socket handler = (Socket)ar.AsyncState; // Complete sending the data to the remote device. int bytesSent = handler.EndSend(ar); Console.WriteLine("Sent {} bytes to client.", bytesSent); handler.Shutdown(SocketShutdown.Both); handler.Close(); } catch (Exception e) { Console.WriteLine(e.ToString()); } } public static int Main(String[] args) { StartListening(); return ; } }
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持脚本之家。
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