C＃中的long值枚举 [英] Enum of long values in C#

问题描述

为什么要声明？

public enum ECountry : long
{
    None,
    Canada,
    UnitedStates
}

是否需要强制转换其任何值？

require a cast for any of its values?

long ID = ECountry.Canada;
// Error Cannot implicitly convert type 'ECountry' to 'long'.
// An explicit conversion exists (are you missing a cast?)

有没有办法获取

这也不起作用，例如：

public enum ECountry : long
{
    None = 0L,
    Canada = 1L,
    UnitedStates=2L
}

推荐答案

问题不是不是，基础类型仍然是 int 。 long ，您可以为成员分配 long 个值。但是，您可以从不仅将枚举值分配给整数类型而无需强制转换。这应该起作用：

The issue is not that the underlying type is still int. It's long, and you can assign long values to the members. However, you can never just assign an enum value to an integral type without a cast. This should work:

public enum ECountry : long
{
    None,
    Canada,
    UnitedStates = (long)int.MaxValue + 1;
}

// val will be equal to the *long* value int.MaxValue + 1
long val = (long)ECountry.UnitedStates;

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