LINQ DISTINCT运算符，忽略大小写？ [英] LINQ Distinct operator, ignore case?

问题描述

由于以下简单的例子：

    List<string> list = new List<string>() { "One", "Two", "Three", "three", "Four", "Five" };

    CaseInsensitiveComparer ignoreCaseComparer = new CaseInsensitiveComparer();

    var distinctList = list.Distinct(ignoreCaseComparer as IEqualityComparer<string>).ToList();

看样子CaseInsensitiveComparer没有实际使用做了区分大小写的比较。

It appears the CaseInsensitiveComparer is not actually being used to do a case-insensitive comparison.

在换句话说 distinctList 包含相同数量的项目作为列表即可。相反，我所期望的，例如，三和三被视为相等。

In other words distinctList contains the same number of items as list. Instead I would expect, for example, "Three" and "three" be considered equal.

我缺少的东西，或这是与DISTINCT运营商的问题？

Am I missing something or is this an issue with the Distinct operator?

推荐答案

StringComparer 做了你所需要的：

List<string> list = new List<string>() {
    "One", "Two", "Three", "three", "Four", "Five" };

var distinctList = list.Distinct(
    StringComparer.CurrentCultureIgnoreCase).ToList();

（或不变/序号的/ etc取决于你比较数据）

(or invariant / ordinal / etc depending on the data you are comparing)

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