程序代码：

using System.Collections.Generic;
using System;

namespace Test
{
    class Test
    {
        static void Main()
        {
            // 第一个方法
            Dictionary<string, string> map = new Dictionary<string, string>();

            map["first"] = "one";
            map["second"] = "two";
            map["third"] = "three";

            // 第二个方法
            map = new Dictionary<string, string>
            {
                {"first", "one"},
                {"second", "two"},
                {"third", "three"}
            };

            foreach (var pair in map)
            {
                Console.WriteLine("{0}: {1}", pair.Key, pair.Value);
            }

            Console.ReadLine();
        }
    }
}