如何在C#List <T> LINQ中找到重复项和原始文件？

Question

我在这里阅读了几乎所有关于在C#中查找List类型字符串中的重复项的答案,但我还没有找到我需要的解决方案.

假设我有一个清单:

List<String> list = new List<String>{"6","1","2","4","6","5","1","2","1","2"};

我想要检索的是重复值及其原始文件,在新列表中,以便生成的列表如下所示:

List<String> duplist = {"6","6","1","1","1,","2","2","2"};

Answer 1

我想到的第一种方法是:

List<String> duplist = list
    .GroupBy(str => str)
    .Where(g=> g.Count() != 1)
    .SelectMany(g => g)
    .ToList();

如果有人有兴趣,这是查询语法:

var dups = from str in list
           group str by str into g
           where g.Count() != 1
           from str in g
           select str;

List<String> duplist = dups.ToList();