using System;

    using System.Linq;

using System.Threading;

using System.Threading.Tasks;

​

public class Program

{

    public static void Main()

    {

        var e = MyEnum.Original | MyEnum.Thumbnail;

        Console.WriteLine(e); //Original, Thumbnail

        e |= MyEnum.aaa;;

        Console.WriteLine(e); //Original, Thumbnail, aaa

        Console.WriteLine(e.HasFlag(MyEnum.aaa)); //true

    }

​

}

​

[Flags]

public enum MyEnum {

Original = 1,

Thumbnail = 2,

aaa = 4,

bbb = 8}