C# Socket异步通信
C# Socket异步通信
TCPServer
1、使用的通讯通道：socket
2、用到的基本功能：
Bind,
Listen,
BeginAccept
EndAccept
BeginReceive
EndReceive
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：
Code
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：
Code
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：
Code
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:
Code
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：
Code
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
1 using System;
2 using System.Net;
3 using System.Net.Sockets;
4 using System.Text;
5 using System.Threading;
6
7 // State object for reading client data asynchronously
8 public class StateObject
9 {
10 // Client socket.
11 public Socket workSocket = null;
12 // Size of receive buffer.
13 public const int BufferSize = 1024;
14 // Receive buffer.
15 public byte[] buffer = new byte[BufferSize];
16 // Received data string.
17 public StringBuilder sb = new StringBuilder();
18 }
19
20 public class AsynchronousSocketListener
21 {
22 // Thread signal.
23 public static ManualResetEvent allDone = new ManualResetEvent(false);
24
25 public AsynchronousSocketListener()
26 {
27 }
28
29 public static void StartListening()
30 {
31 // Data buffer for incoming data.
32 byte[] bytes = new Byte[1024];
33
34 // Establish the local endpoint for the socket.
35 // The DNS name of the computer
36 // running the listener is "host.contoso.com".
37 //IPHostEntry ipHostInfo = Dns.Resolve(Dns.GetHostName());
38 IPAddress ipAddress = IPAddress.Parse("192.168.1.104");
39
40 IPEndPoint localEndPoint = new IPEndPoint(ipAddress, 11000);
41
42 // Create a TCP/IP socket.
43 Socket listener = new Socket(AddressFamily.InterNetwork,
44 SocketType.Stream, ProtocolType.Tcp);
45
46 // Bind the socket to the local endpoint and listen for incoming connections.
47 try
48 {
49 listener.Bind(localEndPoint);
50 listener.Listen(100);
51 while (true)
52 {
53 // Set the event to nonsignaled state.
54 allDone.Reset();
55
56 // Start an asynchronous socket to listen for connections.
57 Console.WriteLine("Waiting for a connection");
58 listener.BeginAccept(
59 new AsyncCallback(AcceptCallback),
60 listener);
61
62 // Wait until a connection is made before continuing.
63 allDone.WaitOne();
64 }
65 }
66 catch (Exception e)
67 {
68 Console.WriteLine(e.ToString());
69 }
70
71 Console.WriteLine("\nPress ENTER to continue");
72 Console.Read();
73 }
74
75 public static void AcceptCallback(IAsyncResult ar)
76 {
77 // Signal the main thread to continue.
78 allDone.Set();
79
80 // Get the socket that handles the client request.
81 Socket listener = (Socket)ar.AsyncState;
82 Socket handler = listener.EndAccept(ar);
83
84 // Create the state object.
85 StateObject state = new StateObject();
86 state.workSocket = handler;
87 handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReadCallback), state);
88 }
89
90 public static void ReadCallback(IAsyncResult ar)
91 {
92 String content = String.Empty;
93
94 // Retrieve the state object and the handler socket
95 // from the asynchronous state object.
96 StateObject state = (StateObject)ar.AsyncState;
97 Socket handler = state.workSocket;
98
99 // Read data from the client socket.
100 int bytesRead = handler.EndReceive(ar);
101
102 if (bytesRead > 0)
103 {
104 // There might be more data, so store the data received so far.
105 state.sb.Append(Encoding.ASCII.GetString(
106 state.buffer, 0, bytesRead));
107
108 // Check for end-of-file tag. If it is not there, read
109 // more data.
110 content = state.sb.ToString();
111 if (content.IndexOf("<EOF>") > -1)
112 {
113 // All the data has been read from the
114 // client. Display it on the console.
115 Console.WriteLine("Read {0} bytes from socket. \n Data : {1}",content.Length, content);
116
117 // Echo the data back to the client.
118 Send(handler, content);
119 }
120 else
121 {
122 // Not all data received. Get more.
123 handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReadCallback), state);
124 }
125 }
126 }
127
128 private static void Send(Socket handler, String data)
129 {
130 // Convert the string data to byte data using ASCII encoding.
131 byte[] byteData = Encoding.ASCII.GetBytes(data);
132
133 // Begin sending the data to the remote device.
134 handler.BeginSend(byteData, 0, byteData.Length, 0,
135 new AsyncCallback(SendCallback), handler);
136 }
137
138
139
140 private static void SendCallback(IAsyncResult ar)
141
142 {
143 try
144 {
145 // Retrieve the socket from the state object.
146 Socket handler = (Socket)ar.AsyncState;
147
148 // Complete sending the data to the remote device.
149 int bytesSent = handler.EndSend(ar);
150 Console.WriteLine("Sent {0} bytes to client.", bytesSent);
151 handler.Shutdown(SocketShutdown.Both);
152 handler.Close();
153 }
154
155 catch (Exception e)
156
157 {
158 Console.WriteLine(e.ToString());
159 }
160 }
161
162 public static int Main(String[] args)
163
164 {
165 StartListening();
166 return 0;
167 }
168
169 }
posted on 2011-04-29 09:58 kingmoon 阅读(47239) 评论(4) 编辑 收藏 举报
