如何将标准 DayOfWeek 与 Flag 进行比较

Question

我有自己的 DaysOfWeek Flag 枚举（类似于https://learn.microsoft.com/en-us/previous-versions/ms886541(v=msdn.10)）[Flags]public enum DayOfWeek{    Sunday = 0,    Monday = 1,    Tuesday = 2,    Wednesday = 4,    Thursday = 8,    Friday = 16,    Saturday = 32}我需要将标准的 DayOfWeek 与我的进行比较。我怎样才能做到这一点？

Answer 1

由于您的枚举使用与内置相同的天数顺序DayOfWeek，因此您需要做的就是使用DayOfWeektype 的变量作为的指数2，然后将其与您的枚举变量按位与运算。

像这样的东西（这将检查Monday你的枚举标志1是否存在）：

MyDayOfWeek Days = MyDayOfWeek.Monday | MyDayOfWeek.Friday;

DayOfWeek D = DayOfWeek.Monday;

var Mask = 1 << (int)D;

if ((Mask & (int)Days) == Mask)

  //Do whatever;

我已将您的枚举重命名为MyDaysOfWeek，而DayOfWeek是内置 .NET 类型。你可以在一周中的任何一天做同样的事情。

Answer 2

最后，我有解决方案

拥有带有标志的 DaysOfWeek：

[Flags]

public enum DaysOfWeek

{

    None = 0,

    Sunday = 1 << 0,

    Monday = 1 << 1,

    Tuesday = 1 << 2,

    Wednesday = 1 << 3,

    Thursday = 1 << 4,

    Friday = 1 << 5,

    Saturday = 1 << 6,

}

由于自己的枚举具有相同的天数，我们可以编写扩展方法将标准 DayOfWeek 转换为自己的

public static class EnumExtensions

{

    public static DaysOfWeek ToFlag(this DayOfWeek dayOfWeek)

    {

        var mask = 1 << (int)dayOfWeek;

        return (DaysOfWeek)Enum.ToObject(typeof(DaysOfWeek), mask);

    }

}

和用法：

  var days = DaysOfWeek.Sunday | DaysOfWeek.Friday;

  var day = DayOfWeek.Sunday;

  var ownDay = day.ToFlag();

  if (days.HasFlag(ownDay))

      // Do whatever;

Answer 3

public enum BitwiseDayOfWeek

{

    Sunday   = 1,

    Monday   = 2,

    Tuesday  = 4,

    Wednesday    = 8,

    Thursday     = 16,

    Friday   = 32,

    Saturday     = 64

}

public class Program

{

    public static void Main(string[] args)

    {

        BitwiseDayOfWeek scheduledDayOfWeek

            = BitwiseDayOfWeek.Saturday | BitwiseDayOfWeek.Sunday;

        // turn System.DayOfWeek (DateTime.Now.DayOfWeek) into BitwiseDayOfWeek

        BitwiseDayOfWeek currentDayOfWeek

            = (BitwiseDayOfWeek)Math.Pow(2, (double)DateTime.Now.DayOfWeek);

        // test if today is the scheduled day

        if ( (currentDayOfWeek & scheduledDayOfWeek) == currentDayOfWeek )

            Console.WriteLine(currentDayOfWeek);

        Console.WriteLine("---------------------");

        Console.ReadLine();

    }

}

Answer 4

如果您像这样更改枚举：

[Flags]

public enum DayOfWeek

{

    Sunday = 0,

    Monday = 1,

    Tuesday = 2,

    Wednesday = 3,

    Thursday = 4,

    Friday = 5,

    Saturday = 6

}

你可以试试这个：

class Program

{

    public static bool Equal(DayOfWeek mine, System.DayOfWeek cSharp)

    {

        int mineInt = (int)mine;

        int cSharpInt = (int)cSharp;

        return mineInt == cSharpInt;

    }

    static void Main(string[] args)

    {

        DateTime dateTime = DateTime.Now;

        DayOfWeek dayOfWeek = DayOfWeek.Sunday;

        bool areEqual = Equal(dayOfWeek, dateTime.DayOfWeek);

        Console.WriteLine(areEqual);

        Console.ReadKey();

    }

}

如果你不能改变你的枚举，你可以试试这个：

class Program

{

    public static bool Equal(DayOfWeek mine, System.DayOfWeek cSharp)

    {

        if (mine == DayOfWeek.Friday && cSharp == System.DayOfWeek.Friday       || 

            mine == DayOfWeek.Monday && cSharp == System.DayOfWeek.Monday       || 

            mine == DayOfWeek.Saturday && cSharp == System.DayOfWeek.Saturday   || 

            mine == DayOfWeek.Sunday && cSharp == System.DayOfWeek.Sunday       || 

            mine == DayOfWeek.Thursday && cSharp == System.DayOfWeek.Thursday   ||

            mine == DayOfWeek.Tuesday && cSharp == System.DayOfWeek.Tuesday     || 

            mine == DayOfWeek.Wednesday && cSharp == System.DayOfWeek.Wednesday)

            return true;

        return false;

    }

    static void Main(string[] args)

    {

        DateTime dateTime = DateTime.Now;

        DayOfWeek dayOfWeek = DayOfWeek.Tuesday;

        bool areEqual = Equal(dayOfWeek, dateTime.DayOfWeek);

        Console.WriteLine(areEqual);

        Console.ReadKey();

    }

}