/// <summary>
/// Get IPv4 address from notation (xxx.xxx.xxx.xxx) or hostname (asynchronous version)
/// </summary>
public static void ResolveAsync(string ipOrHost, ResolveAddressCallback callback, ResolveAddressExceptionCallback exceptionCallback = null)
{
if (string.IsNullOrEmpty(ipOrHost))
{
throw new ArgumentException("Supplied string must not be empty", "ipOrHost");
}
ipOrHost = ipOrHost.Trim();
IPAddress ipAddress = null;
if (IPAddress.TryParse(ipOrHost, out ipAddress))
{
if (ipAddress.AddressFamily == AddressFamily.InterNetwork)
{
callback(ipAddress);
return;
}
throw new ArgumentException("This method will not currently resolve other than ipv4 addresses");
}
// ok must be a host name
IPHostEntry entry;
try
{
Dns.BeginGetHostEntry(ipOrHost, delegate(IAsyncResult result)
{
try
{
entry = Dns.EndGetHostEntry(result);
}
catch (SocketException ex)
{
if (ex.SocketErrorCode == SocketError.HostNotFound)
{
//LogWrite(string.Format(CultureInfo.InvariantCulture, "Failed to resolve host '{0}'.", ipOrHost));
callback(null);
return;
}
else
{
if (exceptionCallback != null)
{
exceptionCallback(ex);
return;
}
else
{
throw;
}
}
}
if (entry == null)
{
callback(null);
return;
}
// check each entry for a valid IP address
foreach (IPAddress ipCurrent in entry.AddressList)
{
if (ipCurrent.AddressFamily == AddressFamily.InterNetwork)
{
callback(ipCurrent);
return;
}
}
callback(null);
}, null);
}
catch (SocketException ex)
{
if (ex.SocketErrorCode == SocketError.HostNotFound)
{
//LogWrite(string.Format(CultureInfo.InvariantCulture, "Failed to resolve host '{0}'.", ipOrHost));
callback(null);
}
else
{
if (exceptionCallback != null)
{
exceptionCallback(ex);
return;
}
else
{
throw;
}
}
}
}
/// <summary>
/// Get IPv4 endpoint from notation (xxx.xxx.xxx.xxx) or hostname and port number (asynchronous version)
/// </summary>
public static void ResolveAsync(string ipOrHost, int port, ResolveEndPointCallback callback, ResolveAddressExceptionCallback exceptionCallback = null)
{
ResolveAsync(ipOrHost, delegate(IPAddress adr)
{
if (adr == null)
{
callback(null);
}
else
{
callback(new IPEndPoint(adr, port));
}
}, exceptionCallback);
}
