我有一个 TCP 服务器，它不断接收来自不同来源的 TCP 流。我有一个触发停止的外部事件，发生这种情况时，需要释放 TCP 端口。下面的代码可以正常工作，除了闭包。关闭是没有释放端口，TCP端口卡在监听状态。我怎样才能解决这个问题？
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.Windows.Forms;
namespace TestTest
{
public class tcpserver
{
// State object for reading client data asynchronously
public class StateObject
{
// Client socket.
public Socket workSocket = null;
// Size of receive buffer.
public const int BufferSize = 2097152;
// Receive buffer.
public byte[] buffer = new byte[BufferSize];
// Received data string.
public StringBuilder sb = new StringBuilder();
}
public class AsynchronousSocketListener
{
public Form10 m_parent;
Socket parentlistener;
// Incoming data from client.
public static string data = null;
// Thread signal.
public static ManualResetEvent allDone = new ManualResetEvent(false);
public AsynchronousSocketListener()
{
}
public void StartListening(Form10 frm10)
{
m_parent = frm10;
try
{
// Data buffer for incoming data.
byte[] bytes = new Byte[2097152];
int port = Convert.ToInt32(m_parent.textBox2.Text.Trim());
IPAddress ipv4 = IPAddress.Parse(m_parent.comboBox1.SelectedItem.ToString().Trim());
IPEndPoint localEndPoint = new IPEndPoint(ipv4, port);
// Create a TCP/IP socket.
parentlistener = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
parentlistener.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, false);
LingerOption lo = new LingerOption(false, 0);
parentlistener.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Linger, lo);
// Setting the array to have this ip and port
m_parent.m_parent.setUsedIPport(
m_parent.comboBox1.SelectedItem.ToString().Trim() +
":" + m_parent.textBox2.Text.Trim());
// Bind the socket to the local endpoint and
// listen for incoming connections.
try
{
parentlistener.Bind(localEndPoint); // THIS IS THE PORT I WOULD LIKE
// TO RELEASE ON AN EXTERNAL TRIGGER
parentlistener.Listen(100);
while (m_parent.getStopState() == false)
{
//MessageBox.Show("L");
allDone.Reset();
//// Start an asynchronous socket to listen for connections.
parentlistener.BeginAccept(
new AsyncCallback(AcceptCallback), parentlistener);
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
catch (Exception) {
MessageBox.Show("Error binding to tcp port", "ERROR"); return;
}
}
public void AcceptCallback(IAsyncResult ar)
{
try
{
// 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);
LingerOption lo = new LingerOption(false, 0);
handler.SetSocketOption(SocketOptionLevel.Socket,
SocketOptionName.Linger,
lo);
// Create the state object.
StateObject state = new StateObject();
state.workSocket = handler;
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize,
0, new AsyncCallback(ReadCallback), state);
}
catch (Exception er) {
//MessageBox.Show(er.ToString());
}
}
public void ReadCallback(IAsyncResult ar)
{
try
{
String line = String.Empty;
// Retrieve the state object and the handler socket
// from the asynchronous state object.
StateObject state = (StateObject)ar.AsyncState;
Socket handler = state.workSocket;
string temporaryString = "";
// 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));
line = state.sb.ToString(); // This goes into an external
// store, and code is not here
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize,
0, new AsyncCallback(ReadCallback), state);
}
}
}
catch (Exception er) {
//MessageBox.Show(er.ToString());
}
}
public void stopListener()
{
try
{
parentlistener.Shutdown(SocketShutdown.Both);
//parentlistener.Disconnect(true);
parentlistener.Close(); // PROBLEM !!! The code is not releasing
// the port, the tcp port continues to
// remain in the listening state.
parentlistener.Dispose();
}
catch (Exception Ex) {
//MessageBox.Show(Ex.ToString());
}
}
}
}
}