大家好,又见面了,我是你们的朋友全栈君。
title | author | date | CreateTime | categories |
---|---|---|---|---|
C# dotnet core 局域网组播方法
|
lindexi
|
2019-10-30 9:0:48 +0800
|
2019-10-29 12:2:46 +0800
|
dotnet C#
|
我在微软官网找到了用 C# 做 UDP 组播的方法,我优化一些逻辑,保留核心代码,然后加了一点封装
在使用之前需要注意的是组播可以用来做局域网传输,但是组播不是可靠的方案,随时可能因为路由器等发送失败或无法接收消息
使用组播的方法是创建 Socket 通过 UDP 向组播地址发送数据或从组播地址接收数据
可以作为组播的地址是 239.0.0.0~239.255.255.255 的范围,这个范围是局域网可用。但实际可用或不可用还需要靠实际的路由器
首先创建一个 Socket 然后绑定到端口
private IPAddress LocalIpAddress { set; get; } = IPAddress.Any;
private Socket MulticastSocket { get; }
private const int MulticastPort = 15003;
private void TryBindSocket()
{
for (var i = MulticastPort; i < 65530; i++)
{
try
{
EndPoint localEndPoint = new IPEndPoint(LocalIpAddress, i);
MulticastSocket.Bind(localEndPoint);
return;
}
catch (SocketException e)
{
Console.WriteLine(e);
}
}
}
绑定的端口是用来接收的端口,所以绑定失败不会影响发送
绑定完成需要加入组播网络
var multicastOption = new MulticastOption(MulticastAddress, IPAddress.Any);
MulticastSocket.SetSocketOption(SocketOptionLevel.IP,
SocketOptionName.AddMembership,
multicastOption);
/// <summary>
/// 组播地址
/// <para/>
/// 224.0.0.0~224.0.0.255为预留的组播地址(永久组地址),地址224.0.0.0保留不做分配,其它地址供路由协议使用;
/// <para/>
/// 224.0.1.0~224.0.1.255是公用组播地址,可以用于Internet;
/// <para/>
/// 224.0.2.0~238.255.255.255为用户可用的组播地址(临时组地址),全网范围内有效;
/// <para/>
/// 239.0.0.0~239.255.255.255为本地管理组播地址,仅在特定的本地范围内有效。
/// </summary>
public IPAddress MulticastAddress { set; get; }
需要注意,上面代码的 LocalIpAddress 写的是 Any 也就是只有在默认的网卡是和其他设备网段才能访问
如果发现其他设备不能接收到信息,那么请修改 LocalIpAddress 为你设备的地址
接收方法和接收其他相同
private void ReceiveBroadcastMessages()
{
// 接收需要绑定 MulticastPort 端口
var bytes = new byte[MaxByteLength];
EndPoint remoteEndPoint = new IPEndPoint(IPAddress.Any, 0);
try
{
while (true)
{
var length = MulticastSocket.ReceiveFrom(bytes, ref remoteEndPoint);
Console.WriteLine(Encoding.UTF8.GetString(bytes, 0, length));
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
接收和发送都是二进制
/// <summary>
/// 发送组播
/// </summary>
/// <param name="message"></param>
public void SendBroadcastMessage(string message)
{
try
{
var endPoint = new IPEndPoint(MulticastAddress, MulticastPort);
var byteList = Encoding.UTF8.GetBytes(message);
MulticastSocket.SendTo(byteList, endPoint);
}
catch (Exception e)
{
Console.WriteLine("\n" + e);
}
}
所有代码
internal class PeerMulticastFinder : IDisposable
{
/// <inheritdoc />
public PeerMulticastFinder()
{
MulticastSocket = new Socket(AddressFamily.InterNetwork,
SocketType.Dgram,
ProtocolType.Udp);
MulticastAddress = IPAddress.Parse("230.138.100.2");
}
/// <summary>
/// 寻找局域网设备
/// </summary>
public void FindPeer()
{
// 实际是反过来,让其他设备询问
StartMulticast();
var ipList = GetLocalIpList().ToList();
var message = string.Join(';',ipList);
SendBroadcastMessage(message);
// 先发送再获取消息,这样就不会收到自己发送的消息
ReceivedMessage += (s, e) => { Console.WriteLine($"找到 {
e}"); };
}
/// <summary>
/// 获取本地 IP 地址
/// </summary>
/// <returns></returns>
private IEnumerable<IPAddress> GetLocalIpList()
{
var host = Dns.GetHostEntry(Dns.GetHostName());
foreach (var ip in host.AddressList)
{
if (ip.AddressFamily == AddressFamily.InterNetwork)
{
yield return ip;
}
}
}
/// <summary>
/// 组播地址
/// <para/>
/// 224.0.0.0~224.0.0.255为预留的组播地址(永久组地址),地址224.0.0.0保留不做分配,其它地址供路由协议使用;
/// <para/>
/// 224.0.1.0~224.0.1.255是公用组播地址,可以用于Internet;
/// <para/>
/// 224.0.2.0~238.255.255.255为用户可用的组播地址(临时组地址),全网范围内有效;
/// <para/>
/// 239.0.0.0~239.255.255.255为本地管理组播地址,仅在特定的本地范围内有效。
/// </summary>
public IPAddress MulticastAddress { set; get; }
private const int MulticastPort = 15003;
/// <summary>
/// 启动组播
/// </summary>
public void StartMulticast()
{
try
{
// 如果首次绑定失败,那么将无法接收,但是可以发送
TryBindSocket();
// Define a MulticastOption object specifying the multicast group
// address and the local IPAddress.
// The multicast group address is the same as the address used by the server.
// 有多个 IP 时,指定本机的 IP 地址,此时可以接收到具体的内容
var multicastOption = new MulticastOption(MulticastAddress, IPAddress.Parse("172.18.134.16"));
MulticastSocket.SetSocketOption(SocketOptionLevel.IP,
SocketOptionName.AddMembership,
multicastOption);
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
Task.Run(ReceiveBroadcastMessages);
}
/// <summary>
/// 收到消息
/// </summary>
public event EventHandler<string> ReceivedMessage;
private void ReceiveBroadcastMessages()
{
// 接收需要绑定 MulticastPort 端口
var bytes = new byte[MaxByteLength];
EndPoint remoteEndPoint = new IPEndPoint(IPAddress.Any, 0);
try
{
while (!_disposedValue)
{
var length = MulticastSocket.ReceiveFrom(bytes, ref remoteEndPoint);
OnReceivedMessage(Encoding.UTF8.GetString(bytes, 0, length));
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
/// <summary>
/// 发送组播
/// </summary>
/// <param name="message"></param>
public void SendBroadcastMessage(string message)
{
try
{
var endPoint = new IPEndPoint(MulticastAddress, MulticastPort);
var byteList = Encoding.UTF8.GetBytes(message);
if (byteList.Length > MaxByteLength)
{
throw new ArgumentException($"传入 message 转换为 byte 数组长度太长,不能超过{
MaxByteLength}字节")
{
Data =
{
{ "message", message },
{ "byteList", byteList }
}
};
}
MulticastSocket.SendTo(byteList, endPoint);
}
catch (Exception e)
{
Console.WriteLine("\n" + e);
}
}
private IPAddress LocalIpAddress { set; get; } = IPAddress.Any;
private Socket MulticastSocket { get; }
private void TryBindSocket()
{
for (var i = MulticastPort; i < 65530; i++)
{
try
{
EndPoint localEndPoint = new IPEndPoint(LocalIpAddress, i);
MulticastSocket.Bind(localEndPoint);
return;
}
catch (SocketException e)
{
Console.WriteLine(e);
}
}
}
private const int MaxByteLength = 1024;
#region IDisposable Support
private bool _disposedValue = false; // 要检测冗余调用
private void Dispose(bool disposing)
{
if (!_disposedValue)
{
if (disposing)
{
}
MulticastSocket.Dispose();
ReceivedMessage = null;
MulticastAddress = null;
_disposedValue = true;
}
}
// 添加此代码以正确实现可处置模式。
public void Dispose()
{
// 请勿更改此代码。将清理代码放入以上 Dispose(bool disposing) 中。
Dispose(true);
GC.SuppressFinalize(this);
}
#endregion
private void OnReceivedMessage(string e)
{
ReceivedMessage?.Invoke(this, e);
}
}
发布者:全栈程序员-用户IM,转载请注明出处:https://javaforall.cn/147499.html原文链接:https://javaforall.cn
【正版授权,激活自己账号】: Jetbrains全家桶Ide使用,1年售后保障,每天仅需1毛
【官方授权 正版激活】: 官方授权 正版激活 支持Jetbrains家族下所有IDE 使用个人JB账号...