如果我有以下枚举:
public enum ReturnValue{
Success = 0,
FailReason1 = 1,
FailReason2 = 2
//Etc...
}
我能避免铸造,当我回来,是这样的:
Can I avoid casting when I return, like this:
public static int main(string[] args){
return (int)ReturnValue.Success;
}
如果不是,为什么不是一个枚举值当作一个int默认?
If not, why isn't an enum value treated as an int by default?
枚举应该是类型安全的。我认为他们并没有使他们含蓄地浇注料,以阻止其他用途。虽然框架允许您在一个恒定值分配给他们,你应该重新考虑你的意图。如果你主要使用枚举存储常量值,可以考虑使用一个静态类:
enums are supposed to be type safe. I think they didn't make them implicitly castable to discourage other uses. Although the framework allows you to assign a constant value to them, you should reconsider your intent. If you primarily use the enum for storing constant values, consider using a static class:
public static class ReturnValue
{
public const int Success = 0;
public const int FailReason1 = 1;
public const int FailReason2 = 2;
//Etc...
}
这可以让你做到这一点。
That lets you do this.
public static int main(string[] args){
return ReturnValue.Success;
}
修改
在你的执行的要提供值枚举是当你想将它们组合。参见下面的例子:
When you do want to provide values to an enum is when you want to combine them. See the below example:
[Flags] // indicates bitwise operations occur on this enum
public enum DaysOfWeek : byte // byte type to limit size
{
Sunday = 1,
Monday = 2,
Tuesday = 4,
Wednesday = 8,
Thursday = 16,
Friday = 32,
Saturday = 64,
Weekend = Sunday | Saturday,
Weekdays = Monday | Tuesday | Wednesday | Thursday | Friday
}
这枚举然后可以通过按位数学消耗。看到对于一些应用下面的例子
This enum can then be consumed by using bitwise math. See the below example for some applications.
public static class DaysOfWeekEvaluator
{
public static bool IsWeekends(DaysOfWeek days)
{
return (days & DaysOfWeek.Weekend) == DaysOfWeek.Weekend;
}
public static bool IsAllWeekdays(DaysOfWeek days)
{
return (days & DaysOfWeek.Weekdays) == DaysOfWeek.Weekdays;
}
public static bool HasWeekdays(DaysOfWeek days)
{
return ((int) (days & DaysOfWeek.Weekdays)) > 0;
}
public static bool HasWeekendDays(DaysOfWeek days)
{
return ((int) (days & DaysOfWeek.Weekend)) > 0;
}
}