C#详解枚举类型的定义和转换

水深无声 2023-02-28 01:48 25阅读 0赞

**定义枚举类型**

![C\#枚举类型定义][C]

using DocumentFormat.OpenXml.Office2010.Excel;
    using System;
    using System.Collections.Generic;
    using System.Text;
    
    namespace KnowledgePoint
    {
        public enum QQStatus
        {
            // 枚举QQ状态：在线，Q我吧，离开，忙碌，请勿打扰，隐身，离线
            OnLine, QMe, Leave, Busy, PleaseDoNotDisturb, Cloaking, OffLine
        }
        class _23_EnumStringAndInt
        {
            /// <summary>
            /// 枚举类型的类型转换
            /// </summary>
            /// <param name="args"></param>
            static void Main(string[] args)
            {
                #region 枚举类型强转为int类型
                QQStatus sta = QQStatus.OnLine;
                int staIndex = (int)sta;
                Console.WriteLine("枚举类型的值下标从 " + staIndex + " 开始");
                QQStatus OnLine = QQStatus.OnLine;
                int index0 = (int)OnLine;
                QQStatus QMe = QQStatus.QMe;
                int index1 = (int)QMe;
                QQStatus Leave = QQStatus.Leave;
                int index2 = (int)Leave;
                QQStatus Busy = QQStatus.Busy;
                int index3 = (int)Busy;
                QQStatus PleaseDoNotDisturb = QQStatus.PleaseDoNotDisturb;
                int index4 = (int)PleaseDoNotDisturb;
                QQStatus Cloaking = QQStatus.Cloaking;
                int index5 = (int)Cloaking;
                QQStatus OffLine = QQStatus.OffLine;
                int index6 = (int)OffLine;
                Console.WriteLine("枚举下标依次是：");
                Console.WriteLine("{0} - {1}", OnLine, index0);
                Console.WriteLine("{0} - {1}", QMe, index1);
                Console.WriteLine("{0} - {1}", Leave, index2);
                Console.WriteLine("{0} - {1}", Busy, index3);
                Console.WriteLine("{0} - {1}", PleaseDoNotDisturb, index4);
                Console.WriteLine("{0} - {1}", Cloaking, index5);
                Console.WriteLine("{0} - {1}", OffLine, index6);
                #endregion
    
                Console.WriteLine("\n----------------------------------------\n");
    
                #region 枚举类型转为string类型
                QQStatus staOnLine = QQStatus.OnLine;
                string strOnLine = staOnLine.ToString(); // 调用枚举类型的ToString();方法
                Console.WriteLine("自定义枚举的第 1 个元素为：" + strOnLine);
                QQStatus staQMe = QQStatus.QMe;
                string strQMe = staQMe.ToString();
                Console.WriteLine("自定义枚举的第 2 个元素为：" + strQMe);
                QQStatus staLeave = QQStatus.Leave;
                string strLeave = staLeave.ToString();
                Console.WriteLine("自定义枚举的第 3 个元素为：" + strLeave);
                QQStatus staBusy = QQStatus.Busy;
                string strBusy = staBusy.ToString();
                Console.WriteLine("自定义枚举的第 4 个元素为：" + strBusy);
                QQStatus staPleaseDoNotDisturb = QQStatus.PleaseDoNotDisturb;
                string strPleaseDoNotDisturb = staPleaseDoNotDisturb.ToString();
                Console.WriteLine("自定义枚举的第 5 个元素为：" + strPleaseDoNotDisturb);
                QQStatus staCloaking = QQStatus.Cloaking;
                string strCloaking = staCloaking.ToString();
                Console.WriteLine("自定义枚举的第 6 个元素为：" + strCloaking);
                QQStatus staOffLine = QQStatus.OffLine;
                string strOffLine = staOffLine.ToString();
                Console.WriteLine("自定义枚举的第 7 个元素为：" + strOffLine);
                #endregion
    
                Console.WriteLine("\n----------------------------------------\n");
    
                #region int类型强转为枚举类型
                //int target = 0;
                QQStatus staNO_0 = (QQStatus)0;
                Console.WriteLine("数字 0 转为枚举类型的结果为 - " + staNO_0);
                QQStatus staNO_1 = (QQStatus)1;
                Console.WriteLine("数字 1 转为枚举类型的结果为 - " + staNO_1);
                QQStatus staNO_2 = (QQStatus)2;
                Console.WriteLine("数字 2 转为枚举类型的结果为 - " + staNO_2);
                QQStatus staNO_3 = (QQStatus)3;
                Console.WriteLine("数字 3 转为枚举类型的结果为 - " + staNO_3);
                QQStatus staNO_4 = (QQStatus)4;
                Console.WriteLine("数字 4 转为枚举类型的结果为 - " + staNO_4);
                QQStatus staNO_5 = (QQStatus)5;
                Console.WriteLine("数字 5 转为枚举类型的结果为 - " + staNO_5);
                QQStatus staNO_6 = (QQStatus)6;
                Console.WriteLine("数字 6 转为枚举类型的结果为 - " + staNO_6);
                #endregion
    
                Console.WriteLine("\n----------------------------------------\n");
    
                #region string类型转为枚举类型
                string tran_OnLine = "0";
                // 调用Enum的Parse(Type enumType, string value);方法
                QQStatus _OnLine = (QQStatus)Enum.Parse(typeof(QQStatus),tran_OnLine);
                Console.WriteLine("字符串 {0} 转为枚举类型：{1}",tran_OnLine, _OnLine);
                string tran_QMe = "1";
                QQStatus _QMe = (QQStatus)Enum.Parse(typeof(QQStatus), tran_QMe);
                Console.WriteLine("字符串 {0} 转为枚举类型：{1}", tran_QMe, _QMe);
                string tran_Leave = "2";
                QQStatus _Leave = (QQStatus)Enum.Parse(typeof(QQStatus), tran_Leave);
                Console.WriteLine("字符串 {0} 转为枚举类型：{1}", tran_Leave, _Leave);
                string tran_Busy = "3";
                QQStatus _Busy = (QQStatus)Enum.Parse(typeof(QQStatus), tran_Busy);
                Console.WriteLine("字符串 {0} 转为枚举类型：{1}", tran_Busy, _Busy);
                string tran_PleaseDoNotDisturb = "4";
                QQStatus _PleaseDoNotDisturb = (QQStatus)Enum.Parse(typeof(QQStatus), tran_PleaseDoNotDisturb);
                Console.WriteLine("字符串 {0} 转为枚举类型：{1}", tran_PleaseDoNotDisturb, _PleaseDoNotDisturb);
                string tran_Cloaking = "5";
                QQStatus _Cloaking = (QQStatus)Enum.Parse(typeof(QQStatus), tran_Cloaking);
                Console.WriteLine("字符串 {0} 转为枚举类型：{1}", tran_Cloaking, _Cloaking);
                string tran_OffLine = "6";
                QQStatus _OffLine = (QQStatus)Enum.Parse(typeof(QQStatus), tran_OffLine);
                Console.WriteLine("字符串 {0} 转为枚举类型：{1}", tran_OffLine, _OffLine);
                #endregion
    
                Console.ReadKey();
            }
        }
    }

**运行结果**

枚举类型的值下标从 0 开始
    枚举下标依次是：
    OnLine - 0
    QMe - 1
    Leave - 2
    Busy - 3
    PleaseDoNotDisturb - 4
    Cloaking - 5
    OffLine - 6
    
    ----------------------------------------
    
    自定义枚举的第 1 个元素为：OnLine
    自定义枚举的第 2 个元素为：QMe
    自定义枚举的第 3 个元素为：Leave
    自定义枚举的第 4 个元素为：Busy
    自定义枚举的第 5 个元素为：PleaseDoNotDisturb
    自定义枚举的第 6 个元素为：Cloaking
    自定义枚举的第 7 个元素为：OffLine
    
    ----------------------------------------
    
    数字 0 转为枚举类型的结果为 - OnLine
    数字 1 转为枚举类型的结果为 - QMe
    数字 2 转为枚举类型的结果为 - Leave
    数字 3 转为枚举类型的结果为 - Busy
    数字 4 转为枚举类型的结果为 - PleaseDoNotDisturb
    数字 5 转为枚举类型的结果为 - Cloaking
    数字 6 转为枚举类型的结果为 - OffLine
    
    ----------------------------------------
    
    字符串 0 转为枚举类型：OnLine
    字符串 1 转为枚举类型：QMe
    字符串 2 转为枚举类型：Leave
    字符串 3 转为枚举类型：Busy
    字符串 4 转为枚举类型：PleaseDoNotDisturb
    字符串 5 转为枚举类型：Cloaking
    字符串 6 转为枚举类型：OffLine

[C]: /images/20230209/e60e44f133594055a65ce95354062b5c.png