Lambda Expression过滤项目列表 [英] Lambda Expression to filter a list of list of items

问题描述

我有一个项目列表，我想知道是否有人可以用lambda表达式来帮助我过滤该列表.

I have a a list of list of items and I was wondering if someone could help me with a lambda expression to filter this list.

这是我的列表的样子:

List<List<Item>> myList = ExtractList();

这是我的Item类的样子:

Here's what my Item class looks like:

public class Item {
    public string Name {get;set;}
    public string Action {get;set;}
}

我想过滤此列表，并仅获取其中项目名称"为"ABC"且项目"Action"为"123"的项目列表.

I would like to filter this list and get only those List of List of Items where the Item Name = "ABC" and item Action = "123".

感谢您的帮助

推荐答案

简单:

myList.SelectMany(sublist => sublist)
    .Where(item => item.Name == "ABC" && item.Action == "123");

这将为您提供所有列表中的所有项目.

This gives you all the items inside all the lists.

如果要选择包含该项目的子列表，则:

If you want to select sublists that contain the item instead:

myList.Where(sublist => sublist.Any(item => item.Name == "ABC" && item.Action == "123"));

最后，如果您想保留相同的结构，但只保留与过滤器匹配的项目:

And lastly if you want to preserve the same structure but only keep the items that match the filter:

var newList = myList.Select(sublist => sublist
                       .Where(item => item.Name == "ABC" && item.Action == "123")
                       .ToList()).ToList();

这篇关于Lambda Expression过滤项目列表的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！