如何使用LINQ查找和删除集合中的重复对象？

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

class Program
{
    static void Main(string[] args)
    {
        List<string> list = new List<string> { "apple", "banana", "orange", "apple", "banana", "grape" };

        // 查找重复对象
        var duplicates = list.GroupBy(x => x)
                             .Where(g => g.Count() > 1)
                             .Select(y => y.Key);

        Console.WriteLine("重复对象：");
        foreach (var item in duplicates)
        {
            Console.WriteLine(item);
        }

        // 删除重复对象
        var distinctList = list.Distinct().ToList();

        Console.WriteLine("删除重复对象后的集合：");
        foreach (var item in distinctList)
        {
            Console.WriteLine(item);
        }
    }
}

var distinctList = list.GroupBy(x => x).Select(y => y.Key).ToList();