LINQ中的展平列表

今天药忘吃喽~ 2022-11-26 08:55 154阅读 0赞

本文翻译自：[Flatten List in LINQ][]

*I have a LINQ query which returns `IEnumerable<List<int>>` but i want to return only `List<int>` so i want to merge all my record in my `IEnumerable<List<int>>` to only one array.* **我有一个LINQ查询，该查询返回`IEnumerable<List<int>>`但我只想返回`List<int>`所以我想将我的`IEnumerable<List<int>>`所有记录合并到一个数组中。**

*Example :* **范例：**

IEnumerable<List<int>> iList = from number in
        (from no in Method() select no) select number;

*I want to take all my result `IEnumerable<List<int>>` to only one `List<int>`* **我想将我所有的结果`IEnumerable<List<int>>`带到一个`List<int>`**

*Hence, from source arrays: \[1,2,3,4\] and \[5,6,7\]* **因此，从源数组：\[1,2,3,4\]和\[5,6,7\]**

*I want only one array \[1,2,3,4,5,6,7\]* **我只想要一个数组\[1,2,3,4,5,6,7\]**

*Thanks* **谢谢**

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### \#1楼 ###

参考：[https://stackoom.com/question/6FOP/LINQ中的展平列表][https_stackoom.com_question_6FOP_LINQ]

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### \#2楼 ###

尝试[`SelectMany()`][SelectMany]

var result = iList.SelectMany( i => i );

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### \#3楼 ###

像这样？

var iList = Method().SelectMany(n => n);

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### \#4楼 ###

如果您具有`List<List<int>> k` ，则可以执行

List<int> flatList= k.SelectMany( v => v).ToList();

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### \#5楼 ###

iList.SelectMany(x => x).ToArray()

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### \#6楼 ###

*With query syntax:* **使用查询语法：**

var values =
    from inner in outer
    from value in inner
    select value;

[Flatten List in LINQ]: https://oldbug.net/q/6FOP/Flatten-List-in-LINQ
[https_stackoom.com_question_6FOP_LINQ]: https://stackoom.com/question/6FOP/LINQ%E4%B8%AD%E7%9A%84%E5%B1%95%E5%B9%B3%E5%88%97%E8%A1%A8
[SelectMany]: http://msdn.microsoft.com/en-us/library/system.linq.enumerable.selectmany.aspx