您如何获得 ToDictionary() 失败的重复键? [英] How do you get the duplicate key that ToDictionary() has failed on?

问题描述

我正在创建一个 Dictionary 对象，使用 IEnumerable 的 ToDictionary() 扩展方法:

I'm creating a Dictionary object, using IEnumerable's ToDictionary() extension method:

var dictionary = new Dictionary<string, MyType>
    (myCollection.ToDictionary<MyType, string>(k => k.Key));

当它执行时，它会抛出以下ArgumentException:

When it executes, it throws the following ArgumentException:

已添加具有相同密钥的项目.

An item with the same key has already been added.

如何让它告诉我重复键是什么?

How do I get it to tell me what the duplicate key is?

推荐答案

获取重复键:

var duplicateKeys =
  myCollection
 .GroupBy(k => k.Key)
 .Where(g => g.Count() > 1)
 .Select(g => g.Key);

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