/// <summary>
/// 追加文章，如果 <see cref="Articles"/> 数量大于10则忽略。
/// </summary>
/// <param name="articles">文章数组。</param>
public void Append(params Article[] articles)
{
if (articles.NotNull("articles").Length > ArticleMaxCount)
{
throw new ArgumentException(string.Format("文章数量不能大于 {0} 条。", ArticleMaxCount), "articles");
}
Articles = Articles == null ? articles : Articles.Concat(articles.Take(ArticleMaxCount - Articles.Length)).ToArray();
}