static void Main(string[] args)
{
AsyncCallback callBack = new AsyncCallback(ProcessDnsInformation);
string host;
do
{
Console.Write(" Enter the name of a host computer or <enter> to finish: ");
host = Console.ReadLine();
if (host.Length > 0)
{
Interlocked.Increment(ref requestCounter);
HostRequest request = new HostRequest(host);
hostData.Add(request);
Dns.BeginGetHostEntry(host, callBack, request);
}
} while (host.Length > 0);
while (requestCounter > 0)
{
UpdateUserInterface();
}
foreach (HostRequest r in hostData)
{
if (r.ExceptionObject != null)
{
Console.WriteLine("Request for host {0} returned the following error: {1}.",
r.HostName, r.ExceptionObject.Message);
}
else
{
IPHostEntry h = r.HostEntry;
string[] aliases = h.Aliases;
IPAddress[] addresses = h.AddressList;
if (aliases.Length > 0)
{
Console.WriteLine("Aliases for {0}", r.HostName);
for (int j = 0; j < aliases.Length; j++)
{
Console.WriteLine("{0}", aliases[j]);
}
}
if (addresses.Length > 0)
{
Console.WriteLine("Addreses for {0}", r.HostName);
for (int k = 0; k < addresses.Length; k++)
{
Console.WriteLine("{0}", addresses[k].ToString());
}
}
}
}
}
static void ProcessDnsInformation(IAsyncResult result)
{
HostRequest request = (HostRequest)result.AsyncState;
try
{
IPHostEntry host = Dns.EndGetHostEntry(result);
request.HostEntry = host;
}
catch (SocketException e)
{
request.ExceptionObject = e;
}
finally
{
Interlocked.Decrement(ref requestCounter);
}
}