C# 如何使用UDP广播进行网络发现
我想在C#中使用UDP广播进行网络发现。我不知道怎么做。你能给我建议怎么做吗C# 如何使用UDP广播进行网络发现,c#,udp,broadcast,cdp,lldp,C#,Udp,Broadcast,Cdp,Lldp,我想在C#中使用UDP广播进行网络发现。我不知道怎么做。你能给我建议怎么做吗 我想这样做。用C做同样的事情很简单# 服务器: var Server = new UdpClient(8888); var ResponseData = Encoding.ASCII.GetBytes("SomeResponseData"); while (true) { var ClientEp = new IPEndPoint(IPAddress.Any, 0); var ClientReques
我想这样做。用C做同样的事情很简单# 服务器:
var Server = new UdpClient(8888);
var ResponseData = Encoding.ASCII.GetBytes("SomeResponseData");
while (true)
{
var ClientEp = new IPEndPoint(IPAddress.Any, 0);
var ClientRequestData = Server.Receive(ref ClientEp);
var ClientRequest = Encoding.ASCII.GetString(ClientRequestData);
Console.WriteLine("Recived {0} from {1}, sending response", ClientRequest, ClientEp.Address.ToString());
Server.Send(ResponseData, ResponseData.Length, ClientEp);
}
客户:
var Client = new UdpClient();
var RequestData = Encoding.ASCII.GetBytes("SomeRequestData");
var ServerEp = new IPEndPoint(IPAddress.Any, 0);
Client.EnableBroadcast = true;
Client.Send(RequestData, RequestData.Length, new IPEndPoint(IPAddress.Broadcast, 8888));
var ServerResponseData = Client.Receive(ref ServerEp);
var ServerResponse = Encoding.ASCII.GetString(ServerResponseData);
Console.WriteLine("Recived {0} from {1}", ServerResponse, ServerEp.Address.ToString());
Client.Close();
我有同样的问题,但对我来说并不像@rufanov所说的那么容易 以下是我遇到的一些情况:
- 由于我的应用程序在具有多个网络接口的计算机中正常运行,因此我遇到了一个问题,即广播消息仅在其中一个适配器中发送。为了解决这个问题,我必须首先获得所有网络适配器列表,然后逐个发送广播消息并接收应答消息
- 将正确的localIpEndPoint绑定到适配器ip地址是很重要的,否则发送时广播地址会出现问题
public static void SNCT_SendBroadcast(out List<MyDevice> DevicesList)
{
DevicesList = new List<MyDevice>();
byte[] data = new byte[2]; //broadcast data
data[0] = 0x0A;
data[1] = 0x60;
IPEndPoint ip = new IPEndPoint(IPAddress.Broadcast, 45000); //braodcast IP address, and corresponding port
NetworkInterface[] nics = System.Net.NetworkInformation.NetworkInterface.GetAllNetworkInterfaces(); //get all network interfaces of the computer
foreach (NetworkInterface adapter in nics)
{
// Only select interfaces that are Ethernet type and support IPv4 (important to minimize waiting time)
if (adapter.NetworkInterfaceType != NetworkInterfaceType.Ethernet) { continue; }
if (adapter.Supports(NetworkInterfaceComponent.IPv4) == false) { continue; }
try
{
IPInterfaceProperties adapterProperties = adapter.GetIPProperties();
foreach (var ua in adapterProperties.UnicastAddresses)
{
if (ua.Address.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork)
{
//SEND BROADCAST IN THE ADAPTER
//1) Set the socket as UDP Client
Socket bcSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp); //broadcast socket
//2) Set socker options
bcSocket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Broadcast, 1);
bcSocket.ReceiveTimeout = 200; //receive timout 200ms
//3) Bind to the current selected adapter
IPEndPoint myLocalEndPoint = new IPEndPoint(ua.Address, 45000);
bcSocket.Bind(myLocalEndPoint);
//4) Send the broadcast data
bcSocket.SendTo(data, ip);
//RECEIVE BROADCAST IN THE ADAPTER
int BUFFER_SIZE_ANSWER = 1024;
byte[] bufferAnswer = new byte[BUFFER_SIZE_ANSWER];
do
{
try
{
bcSocket.Receive(bufferAnswer);
DevicesList.Add(GetMyDevice(bufferAnswer)); //Corresponding functions to get the devices information. Depends on the application.
}
catch { break; }
} while (bcSocket.ReceiveTimeout != 0); //fixed receive timeout for each adapter that supports our broadcast
bcSocket.Close();
}
}
}
catch { }
}
return;
}
public static void SNCT\u SendBroadcast(列表外设备列表)
{
DeviceList=新列表();
字节[]数据=新字节[2];//广播数据
数据[0]=0x0A;
数据[1]=0x60;
IPEndPoint ip=新IPEndPoint(IPAddress.Broadcast,45000);//广播ip地址和相应的端口
NetworkInterface[]NIC=System.Net.NetworkInformation.NetworkInterface.GetAllNetworkInterfaces();//获取计算机的所有网络接口
foreach(NIC中的网络接口适配器)
{
//仅选择以太网类型且支持IPv4的接口(对于最小化等待时间很重要)
如果(adapter.NetworkInterfaceType!=NetworkInterfaceType.Ethernet){continue;}
if(adapter.Supports(NetworkInterfaceComponent.IPv4)=false){continue;}
尝试
{
IPInterfaceProperties adapterProperties=adapter.GetIPProperties();
foreach(adapterProperties.UnicastAddresses中的var ua)
{
if(ua.Address.AddressFamily==System.Net.Sockets.AddressFamily.InterNetwork)
{
//在适配器中发送广播
//1) 将套接字设置为UDP客户端
Socket bcSocket=新套接字(AddressFamily.InterNetwork,SocketType.Dgram,ProtocolType.Udp);//广播套接字
//2) 设置socker选项
bcSocket.SetSocketOption(SocketOptionLevel.Socket,SocketOptionName.Broadcast,1);
bcSocket.ReceiveTimeout=200;//接收超时200ms
//3) 绑定到当前选定的适配器
IPEndPoint myLocalEndPoint=新IPEndPoint(ua.Address,45000);
bcSocket.Bind(myLocalEndPoint);
//4) 发送广播数据
bcSocket.SendTo(数据,ip);
//在适配器中接收广播
int BUFFER_SIZE_ANSWER=1024;
字节[]缓冲区应答=新字节[缓冲区大小应答];
做
{
尝试
{
bcSocket.Receive(bufferAnswer);
DeviceList.Add(GetMyDevice(bufferAnswer));//获取设备信息的相应函数。取决于应用程序。
}
捕捉{break;}
}while(bcSocket.ReceiveTimeout!=0);//修复了支持广播的每个适配器的接收超时
bcSocket.Close();
}
}
}
捕获{}
}
返回;
}
我知道它很老了,但有些人可能仍然需要它……公认的答案很好,但在服务器端做了一些小小的调整,它就更好了
修复Ilya Suzdalnitski评论(锁定第二个客户端。接收呼叫):
因为每次响应后,服务器都会关闭并重新创建,因此它可以无休止地工作而不锁定。这里有一个不同的解决方案,它是无服务器的。我需要让一群树莓法律专业人士在网络上相互了解,但无法保证谁会活跃。因此,这种方法允许每个人都成为客户!GitHub上提供了完整的库(免责声明:我创建的),这使得整个过程对于UWP应用程序来说真的非常简单 此解决方案假定设备名称是唯一的,并且您希望使用JSON字符串作为通信协议,但是您可以轻松地发送任何其他格式的数据。另外,在实践中,试着抓住一切;) 一般机制: 发现你的衣服 建立你的听众 处理传入数据 发送消息 其想法是发送一条包含您的ip地址和名称的发现消息。然后在接收消息功能中,将ip名称对添加到设备列表中。添加一些逻辑以避免重复,并在给定名称的Ip发生更改时更新Ip地址 作为奖励,您可以让每个设备发送他们知道的设备列表。这允许您在发送方意识到您时不响应,从而最小化udp通信量。您甚至可以让接收者将列表与自己的列表进行比较,以发现其他设备
冗余是UDP的朋友,无法保证数据包会被发送。有关工作示例,请参阅该项目: 服务器定期发送广播消息。客户端接收并处理它们。许多主机信息(操作系统版本、IP地址、网络接口等)发送错误。
它只是将一个包含指定数据的UDP包发送到255.255.255.255-本地网络的广播地址。如果您的计算机和服务器之间没有任何“智能硬件”(如路由器),则它必须响应此包。在所有网络上进行迭代对于意见来说是过分的-大多数发送的包无论如何都不会被交付。。但是,也可以通过遍历
var responseData = Encoding.ASCII.GetBytes("someData");
while (true)
{
var server = new UdpClient(8888);
var clientEp = new IPEndPoint(IPAddress.Any, 0);
var clientRequestData = server.Receive(ref clientEp);
var clientRequest = Encoding.ASCII.GetString(clientRequestData);
Console.WriteLine($"Recived {clientRequest} from {clientEp.Address}, sending
response: {responseData}");
server.Send(responseData, responseData.Length, clientEp);
server.Close();
}
public string IpAddress
{
get
{
var hosts = NetworkInformation.GetHostNames();
foreach (var host in hosts)
{
if (host.Type == HostNameType.Ipv4) return host.DisplayName;
}
return "";
}
}
var udpPort = "1234";
var socket = new DatagramSocket();
socket.MessageReceived += ReceivedDiscoveryMessage;
await socket.BindServiceNameAsync(udpPort);`
async void ReceivedDiscoveryMessage(DatagramSocket socket, DatagramSocketMessageReceivedEventArgs args)
{
// Get the data from the packet
var result = args.GetDataStream();
var resultStream = result.AsStreamForRead();
using (var reader = new StreamReader(resultStream))
{
// Load the raw data into a response object
var potentialRequestString = await reader.ReadToEndAsync();
// Ignore messages from yourself
if (args.RemoteAddress.DisplayName == IpAddress) return;
// Get the message
JObject jRequest = JObject.Parse(potentialRequestString);
// Do stuff with the data
}
}
public async void SendDataMessage(string discoveryMessage)
{
// Get an output stream to all IPs on the given port
using (var stream = await socket.GetOutputStreamAsync(new HostName("255.255.255.255"), udpPort))
{
// Get a data writing stream
using (var writer = new DataWriter(stream))
{
// Write the string to the stream
writer.WriteString(discoveryMessage);
// Commit
await writer.StoreAsync();
}
}
}