Linq列表列表到单个列表 [英] Linq list of lists to single list

问题描述

好像这样的事情本来应该已经回答了，但我找不到.

Seems like this is the kind of thing that would have already been answered but I'm unable to find it.

我的问题很简单，我如何在一个语句中执行此操作，这样我不必使用新的空列表，然后在下一行进行汇总，而只需一个linq语句即可输出最终列表.详细信息是一个项目列表，每个项目都包含一个住所列表，我只想将所有住所都放在一个平面列表中.

My question is pretty simple, how can I do this in one statement so that instead of having to new the empty list and then aggregate in the next line, that I can have a single linq statement that outputs my final list. details is a list of items that each contain a list of residences, I just want all of the residences in a flat list.

var residences = new List<DAL.AppForm_Residences>();
details.Select(d => d.AppForm_Residences).ToList().ForEach(d => residences.AddRange(d));

推荐答案

您要使用SelectMany扩展方法.

var residences = details.SelectMany(d => d.AppForm_Residences).ToList();

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