我有一个非常简单的异步UDP监听器,设置为服务,并且它一直运作得很好,但最近它因为一个SocketException而崩溃了:An existing connection was forcibly closed by the remote host
。 我有三个问题:
- 这是什么原因?(我认为UDP套接字没有连接)
- 如何复制它以进行测试目的?
- 如何干净地处理异常,使一切都可以继续工作?
我的代码大概长这样:
private Socket udpSock;
private byte[] buffer;
public void Starter(){
//Setup the socket and message buffer
udpSock = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
udpSock.Bind(new IPEndPoint(IPAddress.Any, 12345));
buffer = new byte[1024];
//Start listening for a new message.
EndPoint newClientEP = new IPEndPoint(IPAddress.Any, 0);
udpSock.BeginReceiveFrom(buffer, 0, buffer.Length, SocketFlags.None, ref newClientEP, DoReceiveFrom, udpSock);
}
private void DoReceiveFrom(IAsyncResult iar){
try{
//Get the received message.
Socket recvSock = (Socket)iar.AsyncState;
EndPoint clientEP = new IPEndPoint(IPAddress.Any, 0);
int msgLen = recvSock.EndReceiveFrom(iar, ref clientEP);
byte[] localMsg = new byte[msgLen];
Array.Copy(buffer, localMsg, msgLen);
//Start listening for a new message.
EndPoint newClientEP = new IPEndPoint(IPAddress.Any, 0);
udpSock.BeginReceiveFrom(buffer, 0, buffer.Length, SocketFlags.None, ref newClientEP, DoReceiveFrom, udpSock);
//Handle the received message
Console.WriteLine("Recieved {0} bytes from {1}:{2}",
msgLen,
((IPEndPoint)clientEP).Address,
((IPEndPoint)clientEP).Port);
//Do other, more interesting, things with the received message.
} catch (ObjectDisposedException){
//expected termination exception on a closed socket.
// ...I'm open to suggestions on a better way of doing this.
}
}
异常是在recvSock.EndReceiveFrom()行抛出的。