C#枚举的类型

参考文献：

1.https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/keywords/enum

2.https://docs.microsoft.com/zh-cn/dotnet/csharp/programming-guide/enumeration-types

 

枚举：

1.默认情况下，枚举中每个元素的基础类型都为 int。

2.如果未为枚举器列表中的元素指定值，则值将自动按 1 递增。

3.已批准的枚举类型有 byte、sbyte、short、ushort、int、uint, long 或 ulong。

4.枚举数名称中不能含有空格。

5.枚举成员采用驼峰命名

6.若要在枚举上设置标志，请使用按位 OR 运算符，如以下示例所示：// Initialize with two flags using bitwise OR. meetingDays = Days.Tuesday | Days.Thursday;

7.若要确定是否设置了特定标志，请使用按位 AND 运算，如以下示例所示：// Test value of flags using bitwise AND. bool test = (meetingDays & Days.Thursday) == Days.Thursday;

8.使用 System.Enum 方法来发现和操作枚举值

 

[Flags]
enum Days
{
    None = 0x0,
    Sunday = 0x1,
    Monday = 0x2,
    Tuesday = 0x4,
    Wednesday = 0x8,
    Thursday = 0x10,
    Friday = 0x20,
    Saturday = 0x40
}
class MyClass
{
    Days meetingDays = Days.Tuesday | Days.Thursday;
}

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

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

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

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

// Test value of flags using bitwise AND.
bool test = (meetingDays & Days.Thursday) == Days.Thursday;
Console.WriteLine("Thursday {0} a meeting day.", test == true ? "is" : "is not");
// Output: Thursday is a meeting day.

 8.

string s = Enum.GetName(typeof(Day), 4);
Console.WriteLine(s);

Console.WriteLine("The values of the Day Enum are:");
foreach (int i in Enum.GetValues(typeof(Day)))
    Console.WriteLine(i);

Console.WriteLine("The names of the Day Enum are:");
foreach (string str in Enum.GetNames(typeof(Day)))
    Console.WriteLine(str);