c#使用HashSet 集合去重

說明：

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

namespace JsonTest
{
    public class Program
    {
        static void Main(string[] args)
        {
            List<People> list = new List<People>();
            People temp = new People() { Name = "小明", Age = 19 };
            list.Add(new People() { Name = "小明",Age=19 });
            list.Add(new People() { Name = "小紅", Age = 19 });
            list.Add(new People() { Name = "小明", Age = 19 });
            List<People> DistinctList = list.DistinctBy(x=> (x.Name,x.Age)).ToList();
            Console.Read();
        }

        public string GetName(People obj)
        {
            return obj.Name;
        }
    }
    public static class Test
    {
        /// <summary>
        /// 為集合去除重復
        /// </summary>
        /// <typeparam name="TSource">集合類型</typeparam>
        /// <typeparam name="TKey">根據xx標識去重</typeparam>
        /// <param name="source">待去重的集合</param>
        /// <param name="keySelector">去重的標識（可理解為GroupBy的key）</param>
        /// <returns></returns>
        public static IEnumerable<TSource> DistinctBy<TSource, TKey>(this IEnumerable<TSource> source, Func<TSource, TKey> keySelector)
        {
            //創建一個 TKey類型的 HashSet集合
            var seenKeys = new HashSet<TKey>();
            //循環待去重的數組
            foreach (TSource element in source)
            {
                //使用 Hash集合的不能添加重復對象的特性，來判讀是否重復（if能添加成功，則說明當前集合內數據未重復）
                if (seenKeys.Add(keySelector(element)))
                {
                    yield return element;
                }
            }
        }
    }

    /// <summary>
    /// 測試類
    /// </summary>
    public class People
    { 
        public string Name { get; set; }

        public int Age { get; set; }
    }
}