我一直在努力学习使用异步套接字，我确信我的问题非常简单，但我一直很难找到解决方案。我将从MSDN上为Asynchronous Server和Asynchronous Client提供的代码开始。我正在关注代码的工作方式，除了一个大问题：如何获取客户端发送回程序主函数的字符串？我在ReadCallback()函数中看到字符串完全形成的位置。
问题是如何将字符串内容的内容恢复回Main()？我提出了一些意见，试图澄清我想要到达的地方。提前感谢您的帮助。
异步服务器：
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 = 1024;
// 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[1024];
// 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 = 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(100);
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, 0, StateObject.BufferSize, 0,
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 > 0) {
// There might be more data, so store the data received so far.
state.sb.Append(Encoding.ASCII.GetString(
state.buffer,0,bytesRead));
// Check for end-of-file tag. If it is not there, read
// more data.
content = state.sb.ToString();
if (content.IndexOf("<EOF>") > -1) {
// All the data has been read from the
// client. Display it on the console.
Console.WriteLine("Read {0} bytes from socket. \n Data : {1}",
content.Length, content );
// Echo the data back to the client.
// AT THIS POINT content SHOULD HAVE THE STRING SENT
Send(handler, content);
} else {
// Not all data received. Get more.
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
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, 0, byteData.Length, 0,
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 {0} bytes to client.", bytesSent);
handler.Shutdown(SocketShutdown.Both);
handler.Close();
} catch (Exception e) {
Console.WriteLine(e.ToString());
}
}
public static int Main(String[] args) {
StartListening();
// I want to make string here that has the result from ReadCallback so I can then perform other logic on the string.
return 0;
}
}
答案 0 :(得分：2)
你的例子非常正确。你只需要等待输入。在return语句前加上Console.ReadLine();：
public static int Main(String[] args)
{
StartListening();
// I want to make string here that has the result from ReadCallback so I can then perform other logic on the string.
Console.ReadLine();
return 0;
}
如果要打印输入。在Console.WriteLine()方法解码收到的字节后，只需使用ReadCallback：
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));
// Check for end-of-file tag. If it is not there, read
// more data.
content = state.sb.ToString();
// print the stuff to the console
Console.WriteLine(content);
如果您想拥有内容并对其执行某些操作，可以将其声明为静态类变量，并且您可以在main方法中访问它：
public class AsynchronousSocketListener
{
public static string content = "";
public static int Main(String[] args)
{
StartListening();
// I want to make string here that has the result from ReadCallback so I can then perform other logic on the string.
Console.ReadLine();
// wait until the message has arrive and press enter to jump to this line
Console.WriteLine("Now I can do what ever I want with the incoming message: " + content);
// just to be able to read it one more time before the program ends ;)
Console.ReadLine();
return 0;
}
当然，您必须从ReadCallback删除声明。
您必须知道它是异步的，因此您必须等待消息到达。但是如果你在那里打印它，你可以在控制台中看到它。其余的由你决定