使用linq查找重复字段的总数并仅返回一行

using System;
using System.Collections.Generic;
using System.Linq;

public class Program
{
    public static void Main()
    {
        List<string> names = new List<string> { "John", "Jane", "John", "Mary", "Jane" };

        var duplicateNames = names
            .GroupBy(n => n)
            .Where(g => g.Count() > 1)
            .Select(g => new { Name = g.Key, Count = g.Count() });

        foreach (var name in duplicateNames)
        {
            Console.WriteLine($"Name: {name.Name}, Count: {name.Count}");
        }
    }
}

Name: John, Count: 2
Name: Jane, Count: 2