linq问题:查询嵌套集合

寻找答案。

questions.SelectMany(q => q.Answers).Where(a => a.Name == "SomeName")

questions.Where(q => q.Answers.Any(a => a.Name == "SomeName"))

事实上,你会得到答案或问题的集合,你必须使用 First() , FirstOrDefault() , Single() 或 SingleOrDefault() 根据您的需要,获得一个特定的答案或问题。

from question in Questions
from answer in question.Answers
where answer.Name == something
select question // or select answer

List<Questions> questions = //initialization;
var someAnswer = questions.SelectMany(q=>q.Answers)
                          .First(a=>a.Name =="MyName");

var query = from q in questions
            from a in q.Answers
            where a.Name == "Answer Name"
            select a;