使用linq，我如何创建IEnumerable＆lt;＆gt;来自另一个IEnumerable＆lt;＆gt;的属性

Question

我有一个清单：

IEnumerable<Person> people

我希望得到这个：

IEnumerable<Dog> peoplesDogs

其中狗是人对象的属性，也是

 IEnumerable<Dog> 

Answer 1

var peoplesDogs = people.SelectMany(p => p.Dogs);

Answer 2

var peoplesDogs = from p in people 
                  from d in p.Dogs
                  select d;

Answer 3

var peopleDogs = people.Select(p => p.Dogs)

修改

上面会创建一个IEnumerable<IEnumerable<Dog>>，但显然需要的只是IEnumerable<Dog>。

在LukeH的回答中，您需要使用SelectMany来展平：

var peopleDogs = people.SelectMany(p => p.Dogs)

Answer 4

你也可以

var peoplesDogs = from p in people
                  from d in p.Dogs
                  select d;

具有与以下相同的效果：

var peoplesDogs = people.SelectMany(p => p.Dogs)