SortedDictionary<TKey,TValue>正序与反序排序

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SortDictionary
{
    class Program
    {
        static void Main(string[] args)
        {
            TestDictionarySort();
            TestDictionarySort2();
            Console.Read();
        }
        private static void TestDictionarySort()
        {
            SortedDictionary<string, string> sd = new SortedDictionary<string, string>();
            sd.Add("321", "fdsgsags");
            sd.Add("acb", "test test");
            sd.Add("1123", "lslgsgl");
            sd.Add("2bcd13", "value");

            foreach (KeyValuePair<string, string> item in sd)
            {
                Console.Write("键名：" + item.Key + " 键值：" + item.Value+"\r\n");
            }

        }

        private static void TestDictionarySort2()
        {
            SortedDictionary<string, string> sd = new SortedDictionary<string, string>();
            sd.Add("321", "fdsgsags");
            sd.Add("acb", "test test");
            sd.Add("1123", "lslgsgl");
            sd.Add("2bcd13", "value");

            Console.Write("\r\n正序排序数据：\r\n");
            foreach (KeyValuePair<string, string> item in sd)
            {
                Console.Write("键名：" + item.Key + " 键值：" + item.Value + "\r\n");
            }

            //重新封装到Dictionary里（PS：因为排序后我们将不在使用排序了，所以就使用Dictionary）
            Dictionary<string, string> dc = new Dictionary<string, string>();
            foreach (KeyValuePair<string, string> item in sd.Reverse())
            {
                dc.Add(item.Key, item.Value);
            }
            sd = null;
            //再看其输出结果：
            Console.Write("\r\n反序排序数据：\r\n");
            foreach (KeyValuePair<string, string> item in dc)
            {
                Console.Write("键名：" + item.Key + " 键值：" + item.Value + "\r\n");
            } 
        }

    }
}