【C#-枚举】枚举的使用

枚举是用户定义的整数类型。

namespace ConsoleApplication1
{
    /// <summary>
    /// 在枚举中使用一个整数值，来表示一天的阶段
    /// 如：TimeOfDay.Morning返回数字0
    /// </summary>
    class EnumExample
    {
        public enum TimeOfDay
        {
            Morning = 0,
            Afternoon = 1,
            Evening = 2
        }

        public static void Main()
        {
            WriteGreeting(TimeOfDay.Morning);

            //获取枚举的字符串表示
            TimeOfDay time = TimeOfDay.Afternoon;
            Console.WriteLine(time.ToString());  //返回字符串Afternoon

            //从字符串中获取枚举值，并转换为整数
            TimeOfDay time2 = (TimeOfDay)Enum.Parse(typeof(TimeOfDay), "afternoon", true);
            Console.WriteLine((int)time2); //返回数字1

            Console.ReadKey();
        }

        /// <summary>
        /// 把枚举合适的值传给方法，并在switch中迭代可能的值
        /// </summary>
        /// <param name="timeOfDay"></param>
        static void WriteGreeting(TimeOfDay timeOfDay)
        {
            switch (timeOfDay)
            {
                case TimeOfDay.Morning:
                    Console.WriteLine("Good Morning!");
                    break;
                case TimeOfDay.Afternoon:
                    Console.WriteLine("Good Afternoon!");
                    break;
                case TimeOfDay.Evening:
                    Console.WriteLine("Good Evening!");
                    break;
                default:
                    Console.WriteLine("Hello!");
                    break;
            }
        }
    }
}