c# 枚举标志检查字符串是否在标志中

Question

我有一个枚举:

[Flags]
public enum WeekDays
{

    Monday = 1,
    Tuesday = 2,
    Wednesday = 4,
    Thursday = 8,
    Friday = 16,
    Saturday = 32,
    Sunday = 64
}

如果我这样做:

var weekDays = WeekDays.Monday | WeekDays.Tuesday | WeekDays.Friday;

如何检查是否在 weekDays 中设置了字符串，例如 Monday？

Answer 1

检查以下代码。您可以使用 HasFlag属性:

class Program
    {
        [Flags]
        public enum WeekDays
        {

            Monday = 1,
            Tuesday = 2,
            Wednesday = 4,
            Thursday = 8,
            Friday = 16,
            Saturday = 32,
            Sunday = 64
        }

        private static string result;

        static void Main()
        {
            var wd = new WeekDays();
            Console.WriteLine(wd.HasFlag(WeekDays.Monday));

            wd = WeekDays.Monday;

            Console.WriteLine(wd.HasFlag(WeekDays.Monday));

            bool is_defined = Enum.IsDefined(typeof(WeekDays), "Monday");

            Console.WriteLine(is_defined);

            bool is_not_defined = Enum.IsDefined(typeof(WeekDays), "Mondays");

            Console.WriteLine(is_not_defined);

            bool has_flag_by_string = Enum.TryParse<WeekDays>("Monday", out wd);

            Console.WriteLine(has_flag_by_string);

            Console.ReadLine();
        }
    }

编辑

添加了通过字符串检查属性是否存在的功能。

编辑 2

添加了 Enum.TryParse<>解析字符串值。

引用:

https://msdn.microsoft.com/en-us/library/system.enum.hasflag(v=vs.110).aspx