我目前正在一个简单的 udp 客户端/服务器系统上工作,我偶然发现了以下内容:当我尝试在一个使用 UdpClient 的程序中获取 IPEndPoint 的 IP(我使用 IPAdress.Any 获取)时,它起作用了,我得到以下结果(最上面的一个):
但是当我使用普通套接字而不是 UdpClient 时,它无法区分客户端/IP(底部)。下面列出了两者的代码。我想使用套接字的原因是因为使用相同的类来发送和接收(不是同一个实例)很方便并且使代码更容易理解。
首先
bool messageReceived = false;
bool done = false;
const int listenPort = 11000;
UdpClient listener = new UdpClient(listenPort);
IPEndPoint receiveEP = new IPEndPoint(IPAddress.Any, listenPort);
string[] adresses = new string[2];
public void ReceiveCallback(IAsyncResult ar)
{
int id = 0;
Byte[] receiveBytes = listener.EndReceive(ar, ref receiveEP);
for (int i = 0; i < adresses.Length; i++)
{
if (adresses[i] == receiveEP.Address.ToString())
{
id = i;
break;
}
else if (adresses[i] == null)
{
id = i;
adresses[i] = receiveEP.Address.ToString();
break;
}
}
byte[] a= Encoding.ASCII.GetBytes("Is anybody there?");
listener.Send(a, a.Length, receiveEP);
Console.WriteLine("Received message from {0} (client {1}):", adresses[id],id);
string receiveString = Encoding.ASCII.GetString(receiveBytes);
if (receiveString == "stop")
{
done = true;
}
Console.WriteLine("Received: {0}", receiveString);
messageReceived = true;
}
public void ReceiveMessages()
{
Console.WriteLine("listening for messages");
while(!done){
try
{
messageReceived = false;
if (!messageReceived)
{
listener.BeginReceive(new AsyncCallback(ReceiveCallback), null);
}
while (!messageReceived)
{
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
Console.WriteLine("Done receiving messages...");
for (int i = 0; i < adresses.Length; i++)
{
if (adresses[i] != null)
{
Console.WriteLine(adresses[i]);
}
}
Console.ReadLine();
listener.Close();
}'
第二
bool messageReceived = false;
bool done = false;
const int listenPort = 11000;
Socket listener = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
IPEndPoint receiveEP = new IPEndPoint(IPAddress.Any, listenPort);
string[] adresses = new string[2];
byte[] buffer = new byte[1024];
public void ReceiveMessages()
{
listener.Bind(receiveEP);
Console.WriteLine("listening for messages");
while (!done)
{
try
{
messageReceived = false;
if (!messageReceived)
{
listener.BeginReceive(buffer, 0,1024,SocketFlags.None,new AsyncCallback(ReceiveCallback), null);
}
while (!messageReceived)
{
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
Console.WriteLine("Done receiving messages...");
for (int i = 0; i < adresses.Length; i++)
{
if (adresses[i] != null)
{
Console.WriteLine(adresses[i]);
}
}
Console.ReadLine();
listener.Close();
}
public void ReceiveCallback(IAsyncResult ar)
{
int id = 0;
int read = listener.EndReceive(ar);
for (int i = 0; i < adresses.Length; i++)
{
if (adresses[i] == receiveEP.Address.ToString())
{
id = i;
break;
}
else if (adresses[i] == null)
{
id = i;
adresses[i] = receiveEP.Address.ToString();
break;
}
}
Console.WriteLine("Received message from {0} (client {1}):", adresses[id], id);
string receiveString = Encoding.ASCII.GetString(buffer,0,read);
if (receiveString == "stop")
{
done = true;
}
Console.WriteLine("Received: {0}", receiveString);
messageReceived = true;
}'
我已经尝试过 Socket.ReceiveMessageFrom() 并使用它返回的 packetinfo,但即使我从另一台机器发送,我最终也得到了服务器的 ip4。有人可以帮帮我吗?
最佳答案
尽管这从来不应该是问答类型的问题,但我找到了一种让它工作的方法,这意味着 receive() 只需使用即可将 groupEP 更改为数据包发送方的 IP Socket 而不是 UdpClient(我模仿了 UdpClient 的工作方式)。目前,它仍然是同步的(listener.Receive() 是一个阻塞调用),但在不久的将来会改变:
private const int listenPort = 11000;
public static int Main()
{
bool done = false;
Listener listener = new Listener(listenPort);
IPEndPoint groupEP = new IPEndPoint(IPAddress.Any, listenPort);
byte[] buffer = new byte[2048];
string received_data;
try
{
while (!done)
{
Console.WriteLine("Waiting for broadcast");
buffer=listener.Receive(ref groupEP);
received_data = Encoding.ASCII.GetString(buffer);
Console.WriteLine("Received a broadcast from {0}: {1}", groupEP.ToString(), received_data);
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
return 0;
}
}
public class Listener
{
public Socket client;
public AddressFamily adressFamily;
byte[] byte_buffer = new byte[2048];
public int port;
public Listener(int p)
{
port=p;
adressFamily = AddressFamily.InterNetwork;
IPEndPoint localEP;
localEP = new IPEndPoint(IPAddress.Any, port);
client = new Socket(this.adressFamily, SocketType.Dgram, ProtocolType.Udp);
client.Bind(localEP);
}
public byte[] Receive(ref IPEndPoint remoteEP)
{
IPEndPoint ipEndPoint=new IPEndPoint(IPAddress.Any,port);
EndPoint endPoint = (EndPoint)ipEndPoint;
int num = client.ReceiveFrom(byte_buffer, 2048, SocketFlags.None, ref endPoint);
remoteEP = (IPEndPoint)endPoint;
if (num < 2048)
{
byte[] array = new byte[num];
Buffer.BlockCopy(byte_buffer, 0, array, 0, num);
return array;
}
return byte_buffer;
}
关于c# - 使用 IPAddress.Any 获取客户端的 IP,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/34457820/