using System;
public class CSharpLab
{ public enum State
{ Init, Open, Proc, Close, Done = 9
}
public static void Test()
{ State st = State.Init;
//列出所有名稱
foreach (string en in Enum.GetNames(typeof(State)))
Console.WriteLine("Enum Name: " + en); //列舉背後有值, 預設由零開始排, 但也可自訂
//TIPS: typeof(State)與st.GetType()都可取得列舉型別
foreach (int v in Enum.GetValues(st.GetType()))
Console.WriteLine("Enum Value: " + v.ToString()); //將列舉轉為字串
Console.WriteLine("Enum To String: " + st.ToString()); //將字串轉為列舉
st = (State)Enum.Parse(typeof(State), "proc", true);
Console.WriteLine("String To Enum: " + st); try { Console.WriteLine("String To Enum(not found): " + Enum.Parse(typeof(State), "WTF"));
} catch (Exception ex) { Console.WriteLine("Error when Enum.Parse: " + ex.Message); }
//將列舉轉為數字
Console.WriteLine("Enum to Int: " + st + " " + (int)st); //將數字轉回列舉
st = (State)9;
Console.WriteLine("Int to Enum: " + st); //小心數字轉換對不上時不會有錯誤，但會出現非列舉值
st = (State)100;
Console.WriteLine("Int(100) to Enum: " + st); //如果數字有連續，可以用+1, -1找上一個下一個
//注意: 以下範例並未檢查邊界及數值不連續的狀況,
//並非嚴謹寫法，僅為簡單示意，勿用於正式用途
st = State.Proc;
State next = (State)((int)st)+1;
State prev = (State)((int)st)-1;
Console.WriteLine("Now = " + st + " Next = " + next + " Prev = " + prev); }
}