分组为元素字典 [英] Group into a dictionary of elements

问题描述

我有一个类类型为class1的元素列表，如下所示.如何将它们分组为

Hi I have a list of element of class type class1 as show below. How do I group them into a

Dictionary<int,List<SampleClass>>基于组ID

class SampleClass
{
   public int groupID;
   public string someData;
 }                                                                                  

我已经这样做了:

var t =(from data in datas group data by data.groupID into dataGroups select dataGroups).ToDictionary(gdc => gdc.ToList()[0].groupID, gdc => gdc.ToList());

是否有更好的方法做到这一点

Is there a better way of doing thiss

推荐答案

替换将更有效:

gdc => gdc.ToList()[0].groupID

具有:

gdc => gdc.Key

除此之外，看来我会做的.

Other than that, it looks like I would have done.

或者，如果您对LINQ的扩展方法没问题(我个人更喜欢它们)，则可以使用以下方法将其进一步缩短:

Alternately, if you are okay with extension methods over LINQ (I personally prefer them), it can be shortened further still with:

var t = data.GroupBy(data => data.groupID).ToDictionary(gdc => gdc.Key, gdc => gdc.ToList());

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