我正在尝试用C＃编写一个最简单的多线程TCP服务器，它接收来自多个客户端的数据。
每次连接新客户端时，都会建立套接字连接，并将套接字作为参数传递给新的类函数，然后while循环运行并接收数据直到客户端连接。
这里的问题是“socket.receive”没有阻塞并且接收0字节的数据。因此循环连续运行，而不会阻塞socket.receive（代码中的“clientSocket.Receive（bb）”。）。
我使用Chrome浏览器作为客户端进行测试。 即使我使用任何其他客户端，TCP服务器的行为也保持不变。
客户端仅发送一次数据，但服务器不断接收0字节，而循环继续运行。
我粘贴服务器输出以供参考。
请帮助在socket.receive上阻止服务器以等待下一次客户端传输。 奇怪的是，即使收到0个字节，也不会调用异常。
请帮忙。
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Net.Sockets;
using System.Threading;
Threading;
using System.Timers;
using System.Security;
using System.Security.Permissions;
namespace SERVER
{
static class Constants
{
public const int port = 8080;
public const int buffer_size = 512;
}
class Program
{
static public string LocalIPAddress()
{
IPHostEntry host;
string localIP = "";
host = Dns.GetHostEntry(Dns.GetHostName());
foreach (IPAddress ip in host.AddressList)
{
if (ip.AddressFamily == AddressFamily.InterNetwork)
{
localIP = ip.ToString();
break;
}
}
return localIP;
//return ip;
}
static void Main(string[] args)
{
//IPEndPoint ipObj = new IPEndPoint(IPAddress.Parse("Server IP goes here"), 20487); //20487 is port. you can change it according to your wish
System.Net.IPAddress IP = IPAddress.Any;
int port = Constants.port;
TcpListener listnerObj = new TcpListener(IP, port);
listnerObj.Start();
string client_addr;
string[] client_addr_split;
string IP_string = LocalIPAddress();
Console.WriteLine("Server Started on {0}:{1}", IP_string, port);
while (true)
{
Console.WriteLine("================================");
Console.WriteLine("** Waiting For Client **");
Socket clientSocket = listnerObj.AcceptSocket(); // waiting for the client to connect
client_addr = clientSocket.RemoteEndPoint.ToString();
client_addr_split = client_addr.Split(':');
client_addr = client_addr_split[0];
Console.WriteLine("Client Connected {0}", client_addr);
ParameterizedThreadStart thread = delegate { new communication().doCommunicate(clientSocket, client_addr); };
Thread th = new Thread(thread);
th.Start(); // start the thread here
}
}
class communication
{
public int byteReceived;
public byte[] bb;
public void doCommunicate(Socket clientSocket, string client_addr)
{
clientSocket.Blocking = true;
bb = new byte[Constants.buffer_size];
//Console.WriteLine("***** Entered DoCommunicate *****");
while (clientSocket.Connected)
{
//Console.WriteLine("Entered While");
try
{
//Console.WriteLine("Entered TRY");
Console.WriteLine("Waiting to recieve Data from IP : client_addr");
//int ReceivedDataLength = Client.Receive(ReceivedBytes, 0, ReceivedBytes.Length, SocketFlags.None);
byteReceived = clientSocket.Receive(bb, 0, bb.Length, SocketFlags.None);
//byteReceived = clientSocket.Receive(bb);
}
catch (SocketException e)
{
Console.WriteLine("Error: Socket Exception.\n{0}\n{1}.", e.Message, e.ErrorCode);
break;
}
catch (ArgumentNullException e)
{
Console.WriteLine("Error : Argument Null Exception.\n{0}", e.Message);
break;
}
catch (ObjectDisposedException e)
{
Console.WriteLine("Error : Socket Disposed Exception Caught.\n{0}", e.Message);
break;
}
catch (SecurityException e)
{
Console.WriteLine("Error: Security Exception.\n{0}", e.Message);
break;
}
//clientSocketglobal.Send(Encoding.Default.GetBytes("Hello Client"), SocketFlags.None);
Console.WriteLineWriteLine("Received Byte count : {0}, from IP : {1}", byteReceived, client_addr); // Do whatever you want to do with the data recieved. Parsing and storing etc.
Console.WriteLine(Encoding.UTF8.GetString(bb));
}
//Console.WriteLine("While Loop Exited");
Console.WriteLine("Socked and Class Object Disposed");
clientSocket.Close();
clientSocket.Dispose();
GC.Collect();
}
}
}
}
OUTPUT服务器：
Server Started on 10.0.0.2:8080
================================
** Waiting For Client **
Client Connected 10.0.0.2
================================
** Waiting For Client **
Client Connected 10.0.0.2
================================
** Waiting For Client **
Waiting to recieve Data from IP : 10.0.0.2
Waiting to recieve Data from IP : 10.0.0.2
Received Byte count : 386, from IP : 10.0.0.2
GET /HelloWorld HTTP/1.1
Host: 10.0.0.2:8080
Connection: keep-alive
Cache-Control: max-age=0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
User-Agent: Mozilla/5.0 (Windows NT 6.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/30.0.1599.69 Safari/537.36
Accept-Encoding: gzip,deflate,sdch
Accept-Language: en-GB,en-US;q=0.8,en;q=0.6
Waiting to recieve Data from IP : 10.0.0.2
Received Byte count : 0, from IP : 10.0.0.2
Received Byte count : 0, from IP : 10.0.0.2
Waiting to recieve Data from IP : 10.0.0.2
Waiting to recieve Data from IP : 10.0.0.2
Received Byte count : 0, from IP : 10.0.0.2
Received Byte count : 0, from IP : 10.0.0.2
Waiting to recieve Data from IP : 10.0.0.2
Waiting to recieve Data from IP : 10.0.0.2
Received Byte count : 0, from IP : 10.0.0.2
Received Byte count : 0, from IP : 10.0.0.2
Waiting to recieve Data from IP : 10.0.0.2
Waiting to recieve Data from IP : 10.0.0.2
Received Byte count : 0, from IP : 10.0.0.2
Received Byte count : 0, from IP : 10.0.0.2
Waiting to recieve Data from IP : 10.0.0.2
Waiting to recieve Data from IP : 10.0.0.2
Received Byte count : 0, from IP : 10.0.0.2
Received Byte count : 0, from IP : 10.0.0.2
Waiting to recieve Data from IP : 10.0.0.2
Waiting to recieve Data from IP : 10.0.0.2
Received Byte count : 0, from IP : 10.0.0.2
Received Byte count : 0, from IP : 10.0.0.2
Waiting to recieve Data from IP : 10.0.0.2
Waiting to recieve Data from IP : 10.0.0.2
Received Byte count : 0, from IP : 10.0.0.2
Received Byte count : 0, from IP : 10.0.0.2
Waiting to recieve Data from IP : 10.0.0.2
Waiting to recieve Data from IP : 10.0.0.2
Received Byte count : 0, from IP : 10.0.0.2
Received Byte count : 0, from IP : 10.0.0.2
答案 0 :(得分：7)
如果您收到0个字节，这通常意味着发件人已关闭其发送套接字。在Socket中，发送和接收频道是分开的;我希望发生的事情是你的发送（他们的接收）仍然是开放和可用的，因此clientSocket.Connected返回true（你仍然可以向他们发送回复），但是：他们尽快关闭了他们的发送（你的接收）他们发送了他们的有效载荷（这很常见，表示批次的结束）。基本上，您只需要检测0字节接收，并将其视为结束：一旦您获得非肯定答复，就不会再有 曾 的数据传入从收到。所以只需编写你需要编写的任何响应（它们仍然可以监听，即使它们永远不会再说话），并关闭套接字。
作为旁注：在带有Connection: keep-alive的HTTP / 1.1中，可以保持其套接字打开以准备发送下一个请求 - 但它看起来就像在这种情况下，它们只是没有。他们在发出请求后立即关闭了套接字。哪个好。只需提供响应并完全关闭套接字。不再有任何请求进入。