Question

http://msdn.microsoft.com/en-us/library/cc138362.aspx

我引用上面链接中的代码，该代码显示向Enum Type添加值。但它不适合我。代码是预期的输出：我得到实际输出：

请参考代码： **
//预期产出：会议日为周二，周四，周五

//实际输出：会议日为星期五

//预期输出：会议日是星期四，星期五

// Actaul输出：会议日是星期一**

     class Program
{
    enum Days2
    {
        None = 1,
        Sunday = 2,
        Monday = 3,
        Tuesday = 4,
        Wednesday = 5,
        Thursday = 6,
        Friday = 7,
        Saturday = 8
    }



    static void Main(string[] args)
    {
        Days2 meetingDays = Days2.Tuesday | Days2.Thursday;

        // Initialize with two flags using bitwise OR.
        meetingDays = Days2.Tuesday | Days2.Thursday;

        // Set an additional flag using bitwise OR.
        meetingDays = meetingDays | Days2.Friday;


        Console.WriteLine("Meeting days are {0}", meetingDays);
        // Expected Output: Meeting days are Tuesday, Thursday, Friday
        **// Actual Output: Meeting days are  Friday**

        // Remove a flag using bitwise XOR.
        meetingDays = meetingDays ^ Days2.Tuesday;
        Console.WriteLine("Meeting days are {0}", meetingDays);

        // Expected Output: Meeting days are Thursday, Friday
        **// Actaul Output: Meeting days are Monday**

        Console.ReadLine();

    }
}

Answer 1

为了能够使用按位运算来组合枚举值，它们需要具有与2的幂相对应的值。

此外，您应该使用Flags属性标记枚举，并按惯例使用零作为“无标志设置”。例如：

[Flags]
public enum Days2 
{
    None = 0,
    Sunday = 1
    Monday = 2,
    Tuesday = 4,
    Wednesday = 8,
    Thursday = 16,
    Friday = 32,
    Saturday = 64
}

有关详细信息，请参阅C# Programming Guide。

Answer 2

将[Flags]属性添加到枚举。

Answer 3

你忘了使用FlagsAttribute！

http://msdn.microsoft.com/es-es/library/system.flagsattribute(v=vs.80).aspx

Answer 4

查看Days2.Tuesday | Days2.Thursday;的值应该是10.按位AND本质上是一个补充。

如果你想要几天，就这样做，二元风格：

enum Days2
{
    None = 0,
    Sunday = 1,
    Monday = 2,
    Tuesday = 4,
    Wednesday = 8,
    Thursday = 16,
    Friday = 32,
    Saturday = 64    
}

或者像其他人所说的那样使用Flags属性。

Answer 5

使用[Flags]属性标记枚举。

[Flags]
enum Days2
{
    None = 0,
    Sunday = 1,
    Monday = 2,
    Tuesday = 4,
    Wednesday = 8,
    Thursday = 16,
    Friday = 32,
    Saturday = 64
}

向Enum Type变量添加多个值

5 个答案: