使用 LINQ，选择另一个对象列表中的对象列表 [英] Using LINQ, select list of objects inside another list of objects

问题描述

public class ClassA
{
     public string MyString {get; set;}
}

public class ClassB
{
     public List<ClassA> MyObjects {get; set;}
}

List<ClassB> classBList = new List<ClassB>();
var results = (from i in classBList select i.MyObjects).Distinct();

我想要classBList 中所有ClassA 对象的不同列表.我如何使用 LINQ 解决这个问题?我正在考虑嵌套查询，但无法完全弄清楚.非常感谢任何帮助.

I want a distinct list of all the ClassA objects in the classBList. How do I go about this using LINQ? I'm thinking about a nested query, but couldn't quite figure it out. Any help is very appreciated.

推荐答案

您正试图为原始列表中的每个 ClassB 对象选择多个结果对象.

You're trying to select multiple result objects for each ClassB object in the original list.

因此，您正在寻找 SelectMany扩展方法:

Therefore, you're looking for the SelectMany extension method:

var results = classBList.SelectMany(b => b.MyObjects).Distinct();

如果要使用查询表达式，则需要使用 两个 from 子句:

If you want to use query expressions, you'll need to use two from clauses:

var results = (from b in classBList from a in b.MyObjects select a).Distinct();

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