/// <summary>
/// Retrieves the article at the specified ordinal position.
/// </summary>
/// <param name="index">The ordinal position of the article to be retrieved.</param>
/// <returns>A byte array containing the article data.</returns>
/// <example>
/// <code>
/// C#
///
/// NntpClient nntp = new NntpClient();
///
/// nntp.Connect("news.myhost.com");
///
/// NewsGroup group = nntp.SelectGroup("mygroup");
/// //Retrieve article at position 29 in this group.
/// byte[] article29 = group.RetrieveArticle(29);
/// //Retrieve last article in this group.
/// byte[] article = group.RetrieveArticle(group.LastArticle);
///
/// nntp.Disconnect();
///
/// VB.NET
///
/// Dim nntp As New NntpClient
///
/// nntp.Connect("news.myhost.com")
///
/// Dim group As NewsGroup = nntp.SelectGroup("mygroup")
/// 'Retrieve article at position 29 in this group.
/// Dim article29() As Byte = group.RetrieveArticle(29)
/// 'Retrieve last article in this group.
/// Dim article() As Byte = group.RetrieveArticle(group.LastArticle)
///
/// nntp.Disconnect()
///
/// JScript.NET
///
/// var nntp:NntpClient = new NntpClient();
///
/// nntp.Connect("news.myhost.com");
///
/// var group:NewsGroup = nntp.SelectGroup("mygroup");
/// //Retrieve article at position 29 in this group.
/// var article29:byte[] = group.RetrieveArticle(29);
/// //Retrieve last article in this group.
/// var article:byte[] = group.RetrieveArticle(group.LastArticle);
///
/// nntp.Disconnect();
/// </code>
/// </example>
public byte[] RetrieveArticle(int index)
{
_nntp.OnMessageRetrieving(new MessageRetrievingEventArgs(index));
byte[] buffer = _nntp.CommandMultiline("article " + index.ToString());
if (Encoding.ASCII.GetString(buffer, 0, buffer.Length).StartsWith("220"))
{
Pointer = index;
}
_nntp.OnMessageRetrieved(new MessageRetrievedEventArgs(buffer, index));
return(buffer);
}