/*
C# Network Programming
by Richard Blum
Publisher: Sybex
ISBN: 0782141765
*/
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
public class RetryUdpClient
{
private byte[] data = new byte[1024];
private static IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0);
private static EndPoint Remote = (EndPoint)sender;
private int SndRcvData(Socket s, byte[] message, EndPoint rmtdevice)
{
int recv;
int retry = 0;
while (true)
{
Console.WriteLine("Attempt #{0}", retry);
try
{
s.SendTo(message, message.Length, SocketFlags.None, rmtdevice);
data = new byte[1024];
recv = s.ReceiveFrom(data, ref Remote);
} catch (SocketException)
{
recv = 0;
}
if (recv > 0)
{
return recv;
} else
{
retry++;
if (retry > 4)
{
return 0;
}
}
}
}
public RetryUdpClient()
{
string input, stringData;
int recv;
IPEndPoint ipep = new IPEndPoint(
IPAddress.Parse("127.0.0.1"), 9050);
Socket server = new Socket(AddressFamily.InterNetwork,
SocketType.Dgram, ProtocolType.Udp);
int sockopt = (int)server.GetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReceiveTimeout);
Console.WriteLine("Default timeout: {0}", sockopt);
server.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReceiveTimeout, 3000);
sockopt = (int)server.GetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReceiveTimeout);
Console.WriteLine("New timeout: {0}", sockopt);
string welcome = "Hello, are you there?";
data = Encoding.ASCII.GetBytes(welcome);
recv = SndRcvData(server, data, ipep);
if (recv > 0)
{
stringData = Encoding.ASCII.GetString(data, 0, recv);
Console.WriteLine(stringData);
} else
{
Console.WriteLine("Unable to communicate with remote host");
return;
}
while(true)
{
input = Console.ReadLine();
if (input == "exit")
break;
recv = SndRcvData(server, Encoding.ASCII.GetBytes(input), ipep);
if (recv > 0)
{
stringData = Encoding.ASCII.GetString(data, 0, recv);
Console.WriteLine(stringData);
} else
Console.WriteLine("Did not receive an answer");
}
Console.WriteLine("Stopping client");
server.Close();
}
public static void Main()
{
RetryUdpClient ruc = new RetryUdpClient();
}
}
|
