/// <summary>
/// Begins an asynchronous operation to resolve a
/// <see cref="System.Net.IPHostEntry"/> for each of the authoritative name
/// servers for a domain.
/// </summary>
/// <param name="iar">The asynchronous operation result.</param>
/// <returns>
/// The list of <see cref="AK.Net.Dns.DnsName"/> instances for each of the
/// authoritative name servers for the specified <paramref name="domain"/>.
/// </returns>
/// <exception cref="System.ArgumentNullException">
/// Thrown when <paramref name="iar"/> is <see langword="null"/>.
/// </exception>
/// <exception cref="System.ArgumentException">
/// Thrown when the specified async result does not belong to this operation.
/// </exception>
/// <exception cref="System.InvalidOperationException">
/// Thrown when
/// <see cref="M:AK.Net.Dns.IDnsResovler.EndGetNameServers(System.IAsyncResult)"/>
/// has already been called on the specified async result.
/// </exception>
/// <exception cref="AK.Net.Dns.DnsTransportException">
/// Thrown when a transport error occurred during the asynchronous operation.
/// </exception>
/// <exception cref="AK.Net.Dns.DnsResolutionException">
/// Thrown when an error occurred during the resolution, such as the query
/// not being answered.
/// </exception>
public virtual DnsName[] EndGetNameServers(IAsyncResult iar)
{
Guard.NotNull(iar, "iar");
GetNameServersAsyncState state = iar as GetNameServersAsyncState;
if (state == null)
{
throw Guard.InvalidAsyncResult("iar");
}
state.OnEndCalled();
return(state.Result);
}
/// <summary>
/// Begins an asynchronous operation to resolve a <see cref="AK.Net.Dns.DnsName"/>
/// instance for each of the authoritative name servers for the specified
/// <paramref name="domain"/>.
/// </summary>
/// <param name="domain">The domain name.</param>
/// <param name="callback">The method to invoke once the asynchronous operation
/// has completed.</param>
/// <param name="state">The user-defined state object to associate with the
/// asynchronous operation.</param>
/// <returns>The asynchronous operation result.</returns>
/// <exception cref="System.ArgumentNullException">
/// Thrown when <paramref name="domain"/> is <see langword="null"/>.
/// </exception>
public virtual IAsyncResult BeginGetNameServers(DnsName domain, AsyncCallback callback, object state)
{
Guard.NotNull(domain, "domain");
GetNameServersAsyncState asyncState = new GetNameServersAsyncState(callback, state);
asyncState.QueueOperation(delegate {
try {
asyncState.Result = GetNameServers(domain);
} catch (DnsException exc) {
asyncState.Exception = exc;
} finally {
asyncState.OnComplete();
}
});
return(asyncState);
}
