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Die UdpClient-Klasse bietet einfache Methoden zum Senden und Empfangen verbindungsloser UDP-Pakete im synchronen Blockierungsmodus. Da UDP ein verbindungsloses Transportprotokoll ist, müssen Sie vor dem Senden und Empfangen von Daten keine Remote-Host-Verbindung herstellen. Sie müssen lediglich die Standardoptionen für den Remote-Host wie folgt einrichten:
Erstellen Sie eine Instanz der UdpClient-Klasse mit dem Namen des Remote-Hosts und der Portnummer als Parameter.
Erstellen Sie eine Instanz der UdpClient-Klasse und rufen Sie die Connect-Methode auf.
Sie können jede von UdpClient bereitgestellte Sendemethode verwenden, um Daten an das Remote-Gerät zu senden. Verwenden Sie dann die Methode „Receive“, um Daten vom Remote-Host zu empfangen.
Tipp: Wenn Sie einen Standard-Remote-Host angegeben haben, verwenden Sie nicht den Hostnamen oder IPEndPoint, um die Send-Methode aufzurufen. Wenn Sie dies tun, löst UdpClient eine Ausnahme aus.
Mit der UdpClient-Methode können Sie auch Multicast-Pakete senden und empfangen. UdpClient kann mithilfe der JoinMulticastGroup-Methode bei einer Multicast-Gruppe abonniert werden. Sie können auch die DropMulticastGroup-Methode verwenden, um einen UdpClient von einer Multicast-Gruppe abzumelden.
In diesem Abschnitt wird die Verwendung von UdpClient zur Implementierung eines asynchronen, leistungsstarken UDP-Servers vorgestellt
Asynchroner UDP-Server von UdpClient
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net.Sockets;
using System.Net;
namespace NetFrame.Net.UDP.Listener.Asynchronous
{
/// <summary>
/// UdpClient 实现异步UDP服务器
/// </summary>
public class AsyncUDPServer
{
#region Fields
/// <summary>
/// 服务器程序允许的最大客户端连接数
/// </summary>
private int _maxClient;
/// <summary>
/// 当前的连接的客户端数
/// </summary>
//private int _clientCount;
/// <summary>
/// 服务器使用的异步UdpClient
/// </summary>
private UdpClient _server;
/// <summary>
/// 客户端会话列表
/// </summary>
//private List<AsyncUDPState> _clients;
private bool disposed = false;
/// <summary>
/// 数据接受缓冲区
/// </summary>
private byte[] _recvBuffer;
#endregion
#region Properties
/// <summary>
/// 服务器是否正在运行
/// </summary>
public bool IsRunning { get; private set; }
/// <summary>
/// 监听的IP地址
/// </summary>
public IPAddress Address { get; private set; }
/// <summary>
/// 监听的端口
/// </summary>
public int Port { get; private set; }
/// <summary>
/// 通信使用的编码
/// </summary>
public Encoding Encoding { get; set; }
#endregion
#region 构造函数
/// <summary>
/// 异步UdpClient UDP服务器
/// </summary>
/// <param name="listenPort">监听的端口</param>
public AsyncUDPServer(int listenPort)
: this(IPAddress.Any, listenPort,1024)
{
}
/// <summary>
/// 异步UdpClient UDP服务器
/// </summary>
/// <param name="localEP">监听的终结点</param>
public AsyncUDPServer(IPEndPoint localEP)
: this(localEP.Address, localEP.Port,1024)
{
}
/// <summary>
/// 异步UdpClient UDP服务器
/// </summary>
/// <param name="localIPAddress">监听的IP地址</param>
/// <param name="listenPort">监听的端口</param>
/// <param name="maxClient">最大客户端数量</param>
public AsyncUDPServer(IPAddress localIPAddress, int listenPort, int maxClient)
{
this.Address = localIPAddress;
this.Port = listenPort;
this.Encoding = Encoding.Default;
_maxClient = maxClient;
//_clients = new List<AsyncUDPSocketState>();
_server = new UdpClient(new IPEndPoint(this.Address, this.Port));
_recvBuffer=new byte[_server.Client.ReceiveBufferSize];
}
#endregion
#region Method
/// <summary>
/// 启动服务器
/// </summary>
/// <returns>异步TCP服务器</returns>
public void Start()
{
if (!IsRunning)
{
IsRunning = true;
_server.EnableBroadcast = true;
_server.BeginReceive(ReceiveDataAsync, null);
}
}
/// <summary>
/// 停止服务器
/// </summary>
public void Stop()
{
if (IsRunning)
{
IsRunning = false;
_server.Close();
//TODO 关闭对所有客户端的连接
}
}
/// <summary>
/// 接收数据的方法
/// </summary>
/// <param name="ar"></param>
private void ReceiveDataAsync(IAsyncResult ar)
{
IPEndPoint remote=null;
byte[] buffer = null;
try
{
buffer = _server.EndReceive(ar, ref remote);
//触发数据收到事件
RaiseDataReceived(null);
}
catch (Exception)
{
//TODO 处理异常
RaiseOtherException(null);
}
finally
{
if (IsRunning && _server != null)
_server.BeginReceive(ReceiveDataAsync, null);
}
}
/// <summary>
/// 发送数据
/// </summary>
/// <param name="msg"></param>
/// <param name="remote"></param>
public void Send(string msg, IPEndPoint remote)
{
byte[] data = Encoding.Default.GetBytes(msg);
try
{
RaisePrepareSend(null);
_server.BeginSend(data, data.Length, new AsyncCallback(SendCallback), null);
}
catch (Exception)
{
//TODO 异常处理
RaiseOtherException(null);
}
}
private void SendCallback(IAsyncResult ar)
{
if (ar.IsCompleted)
{
try
{
_server.EndSend(ar);
//消息发送完毕事件
RaiseCompletedSend(null);
}
catch (Exception)
{
//TODO 数据发送失败事件
RaiseOtherException(null);
}
}
}
#endregion
#region 事件
/// <summary>
/// 接收到数据事件
/// </summary>
public event EventHandler<AsyncUDPEventArgs> DataReceived;
private void RaiseDataReceived(AsyncUDPState state)
{
if (DataReceived != null)
{
DataReceived(this, new AsyncUDPEventArgs(state));
}
}
/// <summary>
/// 发送数据前的事件
/// </summary>
public event EventHandler<AsyncUDPEventArgs> PrepareSend;
/// <summary>
/// 触发发送数据前的事件
/// </summary>
/// <param name="state"></param>
private void RaisePrepareSend(AsyncUDPState state)
{
if (PrepareSend != null)
{
PrepareSend(this, new AsyncUDPEventArgs(state));
}
}
/// <summary>
/// 数据发送完毕事件
/// </summary>
public event EventHandler<AsyncUDPEventArgs> CompletedSend;
/// <summary>
/// 触发数据发送完毕的事件
/// </summary>
/// <param name="state"></param>
private void RaiseCompletedSend(AsyncUDPState state)
{
if (CompletedSend != null)
{
CompletedSend(this, new AsyncUDPEventArgs(state));
}
}
/// <summary>
/// 网络错误事件
/// </summary>
public event EventHandler<AsyncUDPEventArgs> NetError;
/// <summary>
/// 触发网络错误事件
/// </summary>
/// <param name="state"></param>
private void RaiseNetError(AsyncUDPState state)
{
if (NetError != null)
{
NetError(this, new AsyncUDPEventArgs(state));
}
}
/// <summary>
/// 异常事件
/// </summary>
public event EventHandler<AsyncUDPEventArgs> OtherException;
/// <summary>
/// 触发异常事件
/// </summary>
/// <param name="state"></param>
private void RaiseOtherException(AsyncUDPState state, string descrip)
{
if (OtherException != null)
{
OtherException(this, new AsyncUDPEventArgs(descrip, state));
}
}
private void RaiseOtherException(AsyncUDPState state)
{
RaiseOtherException(state, "");
}
#endregion
#region Close
/// <summary>
/// 关闭一个与客户端之间的会话
/// </summary>
/// <param name="state">需要关闭的客户端会话对象</param>
public void Close(AsyncUDPState state)
{
if (state != null)
{
//_clients.Remove(state);
//_clientCount--;
//TODO 触发关闭事件
}
}
/// <summary>
/// 关闭所有的客户端会话,与所有的客户端连接会断开
/// </summary>
public void CloseAllClient()
{
//foreach (AsyncUDPSocketState client in _clients)
//{
// Close(client);
//}
//_clientCount = 0;
//_clients.Clear();
}
#endregion
#region 释放
/// <summary>
/// Performs application-defined tasks associated with freeing,
/// releasing, or resetting unmanaged resources.
/// </summary>
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
/// <summary>
/// Releases unmanaged and - optionally - managed resources
/// </summary>
/// <param name="disposing"><c>true</c> to release
/// both managed and unmanaged resources; <c>false</c>
/// to release only unmanaged resources.</param>
protected virtual void Dispose(bool disposing)
{
if (!this.disposed)
{
if (disposing)
{
try
{
Stop();
if (_server != null)
{
_server = null;
}
}
catch (SocketException)
{
//TODO
RaiseOtherException(null);
}
}
disposed = true;
}
}
#endregion
}
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Client-Informationen kapseln die Klasse
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net.Sockets;
using System.Net;
namespace NetFrame.Net.UDP.Listener.Asynchronous
{
public class AsyncUDPState
{
// Client socket.
public UdpClient udpClient = 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 IPEndPoint remote = new IPEndPoint(IPAddress.Any, 0);
}
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Serverereignisparameterklasse
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace NetFrame.Net.UDP.Listener.Asynchronous
{
/// <summary>
/// UdpClient 异步UDP服务器事件参数类
/// </summary>
public class AsyncUDPEventArgs : EventArgs
{
/// <summary>
/// 提示信息
/// </summary>
public string _msg;
/// <summary>
/// 客户端状态封装类
/// </summary>
public AsyncUDPState _state;
/// <summary>
/// 是否已经处理过了
/// </summary>
public bool IsHandled { get; set; }
public AsyncUDPEventArgs(string msg)
{
this._msg = msg;
IsHandled = false;
}
public AsyncUDPEventArgs(AsyncUDPState state)
{
this._state = state;
IsHandled = false;
}
public AsyncUDPEventArgs(string msg, AsyncUDPState state)
{
this._msg = msg;
this._state = state;
IsHandled = false;
}
}
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Das Obige ist der Inhalt von UdpClient zur Implementierung eines asynchronen UDP-Servers in der C#-Netzwerkprogrammierung Serienartikel (7). Weitere verwandte Inhalte finden Sie auf der chinesischen PHP-Website (www.php.cn)!
