------解决方案--------------------------------------------------------
在定时器里隔段时间就发送几个字节的数据。如果3次没有返回则断开
------解决方案--------------------------------------------------------
客户端:
30秒发送一个心跳包到服务器
服务器:
接收到心跳包,更新LastHeartbeatTime
并且有一个线程,一分钟扫描一次,如果LastHeartbeatTime超过一分钟没更新的视为下线
------解决方案--------------------------------------------------------
C# code
模拟心跳的机制
使用直接调用函数模拟心跳,没有涉及到socket
写得不好,不要太挑剔
using System;
using System.Collections.Generic;
using System.Threading;
namespace ConsoleApplication1
{
// 客户端离线委托
public delegate void ClientOfflineHandler(ClientInfo client);
// 客户端上线委托
public delegate void ClientOnlineHandler(ClientInfo client);
public class Program
{
/// <summary>
/// 客户端离线提示
/// </summary>
/// <param name="clientInfo"></param>
private static void ClientOffline(ClientInfo clientInfo)
{
Console.WriteLine(String.Format("客户端{0}离线，离线时间：\t{1}", clientInfo.ClientID, clientInfo.LastHeartbeatTime));
}
/// <summary>
/// 客户端上线提示
/// </summary>
/// <param name="clientInfo"></param>
private static void ClientOnline(ClientInfo clientInfo)
{
Console.WriteLine(String.Format("客户端{0}上线，上线时间：\t{1}", clientInfo.ClientID, clientInfo.LastHeartbeatTime));
}
static void Main()
{
// 服务端
Server server = new Server();
// 服务端离线事件
server.OnClientOffline += ClientOffline;
// 服务器上线事件
server.OnClientOnline += ClientOnline;
// 开启服务器
server.Start();
// 模拟100个客户端
Dictionary<Int32, Client> dicClient = new Dictionary<Int32, Client>();
for (Int32 i = 0; i < 100; i++)
{
// 这里传入server只是为了方便而已
Client client = new Client(i + 1, server);
dicClient.Add(i + 1, client);
// 开启客户端
client.Start();
}
System.Threading.Thread.Sleep(1000);
while (true)
{
Console.WriteLine("请输入要离线的ClientID,输入0则退出程序:");
String clientID = Console.ReadLine();
if (!String.IsNullOrEmpty(clientID))
{
Int32 iClientID = 0;
Int32.TryParse(clientID, out iClientID);
if (iClientID > 0)
{
Client client;
if (dicClient.TryGetValue(iClientID, out client))
{
// 客户端离线
client.Offline = true;
}
}
else
{
return;
}
}
}
}
}
/// <summary>
/// 服务端
/// </summary>
public class Server
{
public event ClientOfflineHandler OnClientOffline;
public event ClientOnlineHandler OnClientOnline;
private Dictionary<Int32, ClientInfo> _DicClient;
/// <summary>
/// 构造函数
/// </summary>
public Server()
{
_DicClient = new Dictionary<Int32, ClientInfo>(100);
}
/// <summary>
/// 开启服务端
/// </summary>
public void Start()
{
// 开启扫描离线线程
Thread t = new Thread(new ThreadStart(ScanOffline));
t.IsBackground = true;
t.Start();
}
/// <summary>
/// 扫描离线
/// </summary>
private void ScanOffline()
{
while (true)
{
// 一秒扫描一次
System.Threading.Thread.Sleep(1000);
lock (_DicClient)
{
foreach (Int32 clientID in _DicClient.Keys)
{
ClientInfo clientInfo = _DicClient[clientID];
// 如果已经离线则不用管
if (!clientInfo.State)
{
continue;
}
// 判断最后心跳时间是否大于3秒
TimeSpan sp = System.DateTime.Now - clientInfo.LastHeartbeatTime;
if (sp.Seconds >= 3)
{
// 离线，触发离线事件
if (OnClientOffline != null)
{
OnClientOffline(clientInfo);
}
// 修改状态
clientInfo.State = false;
}
}
}
}
}
/// <summary>
/// 接收心跳包
/// </summary>
/// <param name="clientID">客户端ID</param>
public void ReceiveHeartbeat(Int32 clientID)
{
lock (_DicClient)
{
ClientInfo clientInfo;
if (_DicClient.TryGetValue(clientID, out clientInfo))
{
// 如果客户端已经上线，则更新最后心跳时间
clientInfo.LastHeartbeatTime = System.DateTime.Now;
}
else
{
// 客户端不存在，则认为是新上线的
clientInfo = new ClientInfo();
clientInfo.ClientID = clientID;
clientInfo.LastHeartbeatTime = System.DateTime.Now;
clientInfo.State = true;
_DicClient.Add(clientID, clientInfo);
// 触发上线事件
if (OnClientOnline != null)
{
OnClientOnline(clientInfo);
}
}
}
}
}
/// <summary>
/// 客户端
/// </summary>
public class Client
{
public Server Server;
public Int32 ClientID;
public Boolean Offline;
/// <summary>
/// 构造函数
/// </summary>
/// <param name="clientID"></param>
/// <param name="server"></param>
public Client(Int32 clientID, Server server)
{
ClientID = clientID;
Server = server;
Offline = false;
}
/// <summary>
/// 开启客户端
/// </summary>
public void Start()
{
// 开启心跳线程
Thread t = new Thread(new ThreadStart(Heartbeat));
t.IsBackground = true;
t.Start();
}
/// <summary>
/// 向服务器发送心跳包
/// </summary>
private void Heartbeat()
{
while (!Offline)
{
// 向服务端发送心跳包
Server.ReceiveHeartbeat(ClientID);
System.Threading.Thread.Sleep(1000);
}
}
}
/// <summary>
/// 客户端信息
/// </summary>
public class ClientInfo
{
// 客户端ID
public Int32 ClientID;
// 最后心跳时间
public DateTime LastHeartbeatTime;
// 状态
public Boolean State;
}
}