使用LINQ to删除列表＆LT元素; T＆GT; [英] Using LINQ to remove elements from a List<T>

问题描述

有人说我LINQ查询，如：

Say that I have LINQ query such as:

var authors = from x in authorsList
              where x.firstname == "Bob"
              select x;

由于 authorsList 的类型是名单，其中，作者＆GT; ，我怎么可以删除从 authorsList 元素>是由查询返回到作者？

Given that authorsList is of type List<Author>, how can I delete the Author elements from authorsList that are returned by the query into authors?

或者，换句话说，我怎样才能从 authorsList ？

Or, put another way, how can I delete all of the Bob's from authorsList?

请注意：这是问题的目的，一个简单的例子

Note: This is a simplified example for the purposes of the question.

推荐答案

那么，它会更容易排除它们摆在首位：

Well, it would be easier to exclude them in the first place:

authorsList = authorsList.Where(x => x.FirstName != "Bob").ToList();

然而，这只会改变，而不是从previous集合中移除作者 authorsList 的价值。另外，您也可以使用 removeall过 ：

However, that would just change the value of authorsList instead of removing the authors from the previous collection. Alternatively, you can use RemoveAll:

authorsList.RemoveAll(x => x.FirstName == "Bob");

如果你真的需要做到这一点的基础上另外一个集合，我会使用HashSet的，removeall过并且包含：

If you really need to do it based on another collection, I'd use a HashSet, RemoveAll and Contains:

var setToRemove = new HashSet<Author>(authors);
authorsList.RemoveAll(x => setToRemove.Contains(x));

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