当我尝试使用或返回它时,我可以避免使用枚举值吗？

Question

如果我有以下枚举:

public enum ReturnValue{
    Success = 0,
    FailReason1 = 1,
    FailReason2 = 2
    //Etc...
}

我回来时可以避免施放,像这样:

public static int main(string[] args){
    return (int)ReturnValue.Success;
}

如果不是,为什么默认情况下不将枚举值视为int？

Answer 1

枚举应该是类型安全的.我认为他们并没有让他们暗中倾倒以阻止其他用途.虽然框架允许您为它们分配常量值,但您应该重新考虑您的意图.如果您主要使用枚举来存储常量值,请考虑使用静态类:

public static class ReturnValue
{
    public const int Success = 0;
    public const int FailReason1 = 1;
    public const int FailReason2 = 2;
    //Etc...
}

这可以让你这样做.

public static int main(string[] args){
    return ReturnValue.Success;
}

编辑

当你不希望提供值枚举是当你想将它们结合起来.见下面的例子:

[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
}

然后可以通过使用按位数学来消耗此枚举.有些应用程序请参见下面的示例.

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;
    }
}

Answer 2

不存在隐式强制转换，因为枚举不必使用 int 作为基础类型。例如，如果您的枚举使用 uint 作为基础类型，则不存在从 uint 到 int 的隐式转换。