[C#]フラグ(ビット演算とEnum)

BitFlagTest.cs

class BitFlagTest : IFlagTest
{
    // ビットシフトで表記
    const int flag1 = 1 << 0;   //2進数:001 10進数:1 16進数:0x1;
    const int flag2 = 1 << 1;   //2進数:010 10進数:2 16進数:0x2;
    const int flag3 = 1 << 2;   //2進数:100 10進数:4 16進数:0x4;

    int flag = 0;

    public void AllFlags_On()
    {
        flag = flag1 | flag2 | flag3;
    }

    public void Flag1_On()
    {
        // 和集合
        // |(OR)演算子
        flag |= flag1;
    }

    public void Flag2_Off()
    {
        // flag2の補集合の積集合
        // &(AND)演算子, ~(反転)演算子
        flag &= ~flag2;
    }

    public void Switch_Flag3()
    {
        // 排他的論理和
        // ^(XOR)演算子
        flag ^= flag3;
    }

    public void Reverse()
    {
        // 反転
        flag = ~flag;
    }

    public void ShowFlag()
    {
        //2進数表記
        var base2 = Convert.ToString(flag, 2).PadLeft(3, '0');
        Console.WriteLine(base2.Substring(base2.Length - 3));
    }

    public bool HasFlag1_or_2()
    {
        return (flag & (flag1 | flag2)) != 0;
    }

    public bool HasFlag2_and_3()
    {
        return (flag & (flag2 | flag3)) == (flag2 | flag3);
    }
}

EnumFlagTest.cs

class EnumFlagTest : IFlagTest
{
    [Flags]
    enum Hoge
    {
        none = 0,
        flag1 = 1,
        flag2 = 2,
        flag3 = 4,
        all = flag1 | flag2 | flag3
    }

    Hoge flag = Hoge.none;

    public void AllFlags_On()
    {
        flag = Hoge.all;
    }

    public void Flag1_On()
    {
        flag |= Hoge.flag1;
    }

    public void Flag2_Off()
    {
        flag &= ~Hoge.flag2;
    }

    public void Switch_Flag3()
    {
        flag ^= Hoge.flag3;
    }

    public bool HasFlag1_or_2()
    {
        return flag.HasFlag(Hoge.flag1) || flag.HasFlag(Hoge.flag2);
    }

    public bool HasFlag2_and_3()
    {
        return flag.HasFlag(Hoge.flag2) && flag.HasFlag(Hoge.flag3);
    }

    public void Reverse()
    {
        //flag = ~flagは負の数になってしまう 
        flag ^= Hoge.all;
    }

    public void ShowFlag()
    {
        Console.WriteLine(flag);
    }
}

IFlagTest.cs

interface IFlagTest
{
    void AllFlags_On();
    void Flag1_On();
    void Flag2_Off();
    bool HasFlag1_or_2();
    bool HasFlag2_and_3();
    void Switch_Flag3();
    void Reverse();
    void ShowFlag();
}

Program.cs

using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        try
        {
            var list = new List<IFlagTest>
            {
                new BitFlagTest(),
                new EnumFlagTest()
            };

            foreach (IFlagTest test in list)
            {
                WriteMethodName("Flag1_On");
                test.Flag1_On();
                test.ShowFlag();

                WriteMethodName("AllFlags_On");
                test.AllFlags_On();
                test.ShowFlag();

                WriteMethodName("Flag2_Off");
                test.Flag2_Off();
                test.ShowFlag();

                WriteMethodName("HasFlag1_or_2");
                Console.WriteLine(test.HasFlag1_or_2());

                WriteMethodName("Reverse");
                test.Reverse();
                test.ShowFlag();

                WriteMethodName("HasFlag2_and_3");
                Console.WriteLine(test.HasFlag2_and_3());

                WriteMethodName("AllFlags_On");
                test.AllFlags_On();
                test.ShowFlag();

                WriteMethodName("Switch_Flag3");
                test.Switch_Flag3();
                test.ShowFlag();

                WriteMethodName("Switch_Flag3");
                test.Switch_Flag3();
                test.ShowFlag();

                Console.WriteLine();
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }
    }

    static void WriteMethodName(string name)
    {
        Console.Write($"{name + ":",-15}");
    }
}