选择对象列表中对象的属性，该对象也位于另一个对象列表中

Question

我有下一个arhitecture：

public class Element
{
    public uint Id { get; set; }
    public ICollection<ElementDetails> elementDetails { get; set; }
}
public class ElementDetails
{
    public string ElementTitle { get; set; }
    public string Content { get; set; }
}

并且List<Element> someList包含数百个元素。 我正在尝试获取包含某个文本的ElementTitle（字符串）列表（我称之为“种子”）。 我想要实现它是一种先行者。这是我的尝试：

List<Element> suggestedElements = someList.Where(s => s.elementDetails.Any(ss => ss.ElementTitle.Contains(seed))).ToList();
List<string> suggestions = suggestedElements .SelectMany(t => t.elementDetails.Select(x => x.ElementTitle)).ToList() }); // contains all ElementTitle, including those ElementTitle that don't contain the "seed"...

如何摆脱那些不含种子的元素？

Answer 1

List<string> suggestions = someList.SelectMany(x => x.elementDetails)
                                   .Where(y => y.ElementTitle.Contains(seed))
                                   .Select(z => z.ElementTitle)
                                   .ToList();

更简单：

List<string> suggestions  = someList.SelectMany(x => x.elementDetails)
                                    .Select(y => y.ElementTitle);
                                    .Where(z => z.Contains(seed))
                                    .ToList();