前言
项目中要实现一个简单的socket服务器端，采用了TcpListener这个类。除了基本的功能之外，有几处需要注意的点。
- 要能同时接收多个客户端的连接，当然，不需要几千个那么多。
- 要能探测到客户端的断开。
- 要能关闭服务器端的监听。
这几个点之间，2和3我没有找到很好的方法，是通过捕获异常的方法解决的。
重点功能
要能同时接收多个客户端的连接
MSDN上面的代码例子是连接一个客户端的情况，我需要可以连接多个客户端，采用了多线程的方式，即连接一个客户端之后，把处理客户端消息的部分用一个线程处理，这样可以继续新的监听，核心代码如下：
private void ThreadListen()
{
while (this.StatusOn)
{
try
{
TcpClient client = this.serverListener.AcceptTcpClient();
this.clientList.Add(client);
this.ShowMsg(string.Format("客户端连接成功! ip = {0} port = {1}", ((IPEndPoint)client.Client.RemoteEndPoint).Address, ((IPEndPoint)client.Client.RemoteEndPoint).Port));
Thread t1 = new Thread(() => ThreadHandleMsg(client));
t1.Start();
}
catch (Exception ex)
{
Log.Error("", ex);
}
}
}
要能探测到客户端的断开
在如下代码之处，while循环的条件会阻塞掉，等待客户端的输入(i = stream.Read(bytes, 0, bytes.Length)) != 0，这个不知道如何判断客户端断开，所以用了try catch比较low的办法。
Byte[] bytes = new Byte[1024];
String data = null;
NetworkStream stream = client.GetStream();
int i;
while ((i = stream.Read(bytes, 0, bytes.Length)) != 0)
{
if (client == null || !client.Connected)
{
break;
}
data = System.Text.Encoding.ASCII.GetString(bytes, 0, i);
this.ShowMsg(string.Format("收到消息: {0}", data));
data = data.ToUpper();
byte[] msg = System.Text.Encoding.ASCII.GetBytes(data);
stream.Write(msg, 0, msg.Length);
this.ShowMsg(string.Format("返回消息: {0}", data));
}
要能关闭服务器端的监听
另外也没有发现如何关闭服务器端的监听，我看了一下stackoverflow，也没发现特别好的办法。代码如下：
public void Close()
{
this.StatusOn = false;
foreach (var client in this.clientList)
{
if (client != null && client.Connected)
{
client.Close();
}
}
this.clientList.Clear();
this.serverListener.Server.Close();
this.serverListener.Stop();
this.ShowMsg("停止监视，关闭连接");
}
全部代码
using log4net;
using System;
using System.Collections.Generic;
using System.Net;
using System.Net.Sockets;
using System.Reflection;
using System.Text;
using System.Threading;
namespace srtc_attools.Bll
{
public class TcpServer
{
private static TcpServer inst;
private static readonly ILog Log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
private List<TcpClient> clientList;
private TcpListener serverListener;
public Action<string> ShowMsg { get; set; }
public bool StatusOn { get; set; }
private TcpServer() { }
public static TcpServer GetInst()
{
if (inst == null)
{
inst = new TcpServer();
}
return inst;
}
private Thread threadListen;
public void Open(string ip, int port)
{
this.clientList = new List<TcpClient>();
this.StatusOn = true;
this.ShowMsg("开始监视，等待连接");
this.serverListener = new TcpListener(IPAddress.Parse(ip), port);
this.serverListener.Start();
threadListen = new Thread(() => ThreadListen());
threadListen.Start();
}
private void ThreadListen()
{
while (this.StatusOn)
{
try
{
TcpClient client = this.serverListener.AcceptTcpClient();
this.clientList.Add(client);
this.ShowMsg(string.Format("客户端连接成功! ip = {0} port = {1}", ((IPEndPoint)client.Client.RemoteEndPoint).Address, ((IPEndPoint)client.Client.RemoteEndPoint).Port));
Thread t1 = new Thread(() => ThreadHandleMsg(client));
t1.Start();
}
catch (Exception ex)
{
Log.Error("", ex);
}
}
}
private void ThreadHandleMsg(TcpClient client)
{
if (client.Connected)
{
try
{
Byte[] bytes = new Byte[1024];
String data = null;
NetworkStream stream = client.GetStream();
int i;
while ((i = stream.Read(bytes, 0, bytes.Length)) != 0)
{
if (client == null || !client.Connected)
{
break;
}
data = System.Text.Encoding.ASCII.GetString(bytes, 0, i);
this.ShowMsg(string.Format("收到消息: {0}", data));
data = data.ToUpper();
byte[] msg = System.Text.Encoding.ASCII.GetBytes(data);
stream.Write(msg, 0, msg.Length);
this.ShowMsg(string.Format("返回消息: {0}", data));
}
}
catch (Exception ex)
{
Log.Error("客户端发生错误\r\n", ex);
if(this.clientList.Contains(client))
{
this.clientList.Remove(client);
this.ShowMsg(string.Format("客户端断开连接! ip = {0} port = {1}", ((IPEndPoint)client.Client.RemoteEndPoint).Address, ((IPEndPoint)client.Client.RemoteEndPoint).Port));
}
}
}
}
public void Close()
{
this.StatusOn = false;
foreach (var client in this.clientList)
{
if (client != null && client.Connected)
{
client.Close();
}
}
this.clientList.Clear();
this.serverListener.Server.Close();
this.serverListener.Stop();
this.ShowMsg("停止监视，关闭连接");
}
}
}