UDP怎样检测回应是否TIMEOUT?

[core0]

//发送部分
public void Send(String sMsg)
{
this.receive_ip();
System.Net.IPEndPoint iep = new System.Net.IPEndPoint(IPAddress.Parse(s_address), i_port);
th = new Thread(new ThreadStart(receive_ip));
th.IsBackground = true;
th.Start();
th.join(2500);
byte[] a = Encoding.UTF8.GetBytes(sMsg);
uc.Send(a, a.Length, iep);
}
//接收部分
public string Receive()
{
while (true)
{
Data = null;
if (th.IsAlive)
{
uc.Close();
uc = new System.Net.Sockets.UdpClient();
Data = "timeout";
}
else
{
Data = Encoding.UTF8.GetString(uc.Receive(ref iep));
}
return Data;
}
}
我这个方法检测不到TIMEOUT,各位还有什么其他方法吗?

[LQknife]

自己设置个时间超时了显示错误信息呗 :-)

[core0]

[Quote=引用 3 楼 LQknife 的回复:]
自己设置个时间超时了显示错误信息呗 :-)
[/Quote]

知道怎样设置就不用发贴问了

[lextm]

                if (!result.IsCompleted)
                {
                    throw SharpTimeoutException.Create(_agent, timeout);
                }

发送的函数会抛出超时异常。上面的代码只要正确处理这个异常就好了。收到回复，一切正常，没收到的话，在catch里面处理异常好了。

[wdgphc]

Lz说的超时是Server的包超时clientm没有收到还是 Client的回复包超时Server没有收到

[lextm]

异步的还需要检测超时？

下面的代码是同步的，摘自#SNMP

/// <summary>
        /// Sends this <see cref="GetRequestMessage"/> and handles the response from agent.
        /// </summary>
        /// <param name="timeout">Timeout.</param>
        /// <param name="port">Port number.</param>
        /// <returns></returns>
        public IList<Variable> Send(int timeout, int port)
        {
            byte[] bytes = _bytes;
            IPEndPoint agent = new IPEndPoint(_agent, port);
            using (UdpClient udp = new UdpClient())
            {
                udp.Send(bytes, bytes.Length, agent);
                IPEndPoint from = new IPEndPoint(IPAddress.Any, 0);
                IAsyncResult result = udp.BeginReceive(null, this);
                result.AsyncWaitHandle.WaitOne(timeout, false);
                if (!result.IsCompleted)
                {
                    throw SharpTimeoutException.Create(_agent, timeout);
                }
                
                bytes = udp.EndReceive(result, ref from);
                udp.Close();
            }
            
            MemoryStream m = new MemoryStream(bytes, false);
            ISnmpMessage message = MessageFactory.ParseMessages(m)[0];
            if (message.TypeCode != SnmpType.GetResponsePdu)
            {
                throw SharpOperationException.Create("wrong response type", _agent);
            }
            
            GetResponseMessage response = (GetResponseMessage)message;
            if (response.SequenceNumber != SequenceNumber)
            {
                throw SharpOperationException.Create("wrong response sequence", _agent);
            }
            
            if (response.ErrorStatus != ErrorCode.NoError)
            {
                throw SharpErrorException.Create(
                    "error in response",
                    _agent,
                    response.ErrorStatus,
                    response.ErrorIndex,
                    response.Variables[response.ErrorIndex - 1].Id);
            }
            
            return response.Variables;
        }

仅作参考。

[core0]

我的代码是发到一个无线设备上,然后这个设备就返回一个代码,假如我SEND到设备上,但超时也拿不到回应怎么办?

[core0]

[Quote=引用 6 楼 wdgphc 的回复:]
Lz说的超时是Server的包超时clientm没有收到还是 Client的回复包超时Server没有收到
[/Quote]

是设备收到我信息然后它回应的超时