使用LINQ，我怎样才能从其他的IEnumerable <>的属性创建的IEnumerable <>

Question

我有一个列表：

IEnumerable<Person> people 

，我想这一点：

IEnumerable<Dog> peoplesDogs 

其中狗是人对象的属性，也是一个

IEnumerable<Dog> 

Answer 1

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

Answer 2

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

编辑

以上将创建一个IEnumerable<IEnumerable<Dog>>但显然我们需要的仅仅是IEnumerable<Dog>。

正如LukeH的答案，你需要使用SelectMany扁平化：

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

Answer 3

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

Answer 4

，你也可以做

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

具有相同的效果：

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