我对UDP套接字相当新,大部分我的套接字体验都与TCP有关。UDP套接字:一个现有的连接被远程主机强制关闭
我使用C#创建一个UDP套接字,绑定它,然后不断侦听来自IP的数据包。但是,当客户端发送数据包时,套接字会引发异常:“现有连接被远程主机强行关闭”。
这是我如何创建UDP套接字:
Socket UDPSocket = new Socket(SocketType.Dgram, ProtocolType.Udp); //Create UDP socket
UDPSocket.Bind(new IPEndPoint(IPAddress.Any, 1338)); //Bind port 1338 from any IP
创建套接字后,我异步接收数据:
UDPSocket.BeginReceiveFrom(newClient.bufferu, 0, AbstractServerClient.BUFFER_SIZE, 0, ref newClient.remoteEndpoint,new AsyncCallback(ReceiveCallbackUDP), newClient);
newClient.remoteEndpoint
从TCP套接字的端点,所以UDP是有效的接收来自TCP连接到的相同IP的数据包。假设其余的参数是有效的(它们在TCP上工作正常)。
的ReceiveCallbackUDP
方法是这样的:
public void ReceiveCallbackUDP(IAsyncResult ar)
{
AbstractServerClient client = (AbstractServerClient)ar.AsyncState;
int bytesRead = UDPSocket.EndReceive(ar);
if (bytesRead > 0)
{
Bitstream data = new Bitstream(client.bufferu, 12);
int bytesProcessed = 12;
while (bytesProcessed < bytesRead)
{
ushort messageLength = data.ReadUInt16(); //Read the message length
byte messageID = data.ReadByte(); //Read the message ID
// Logger.Log("Received message ID: " + messageID.ToString() + " (Size: " + messageLength + " bytes)");
bytesProcessed += messageLength + sizeof(UInt16);
client.GetPacketHandler(messageID).HandlePacket(data); //Process the message
bytesProcessed += 12;
data.Seek(bytesProcessed); //Seek to the next message
}
}
UDPSocket.BeginReceiveFrom(client.bufferu, 0, AbstractServerClient.BUFFER_SIZE, 0, ref client.remoteEndpoint, new AsyncCallback(ReceiveCallbackUDP), client);
}
此功能的插座上呼吁EndReceive()
读取数据,并对其进行处理,并呼吁BeginReceiveFrom
等待更多的数据(异步)。线上抛出异常int bytesRead = UDPSocket.EndReceive(ar);
为什么会发生这种情况?据我了解,UDP是一个无连接套接字,因此异常“现有的连接已关闭”没有任何意义。我在这里做错了什么?
您可能会遇到与此处提到的问题相同的问题:http://stackoverflow.com/questions/7201862/an-existing-connection-was-forcibly-closed-by-the-remote-host –