为什么你只能使用别名来声明枚举而不是.NET类型？

Question

这完美地工作..

public  enum NodeType : byte
{ Search, Analysis, Output, Input, Audio, Movement} 

这会返回编译器错误...

public  enum NodeType : Byte
{ Search, Analysis, Output, Input, Audio, Movement} 

使用反射时也是如此......

那么,有人知道为什么enum-base只是一个整体类型？

Answer 1

可能它只是一个不完整的编译器实现(虽然记录在案).

从技术上讲,这也应该有效,但事实并非如此.

using x = System.Byte;

public  enum NodeType : x
{ Search, Analysis, Output, Input, Audio, Movement}

所以编译器的解析器部分只允许固定列表byte, sbyte, short, ushort, int, uint, long, or ulong.我没有技术限制.

Answer 2

因为规格如此说:

enum-declaration:

    attributesopt
    enum-modifiersopt enum identifier enum-baseopt
    enum-body ;opt
enum-base:

    : integral-type
enum-body:

    { enum-member-declarationsopt }

    { enum-member-declarations , }
Each enum type has a corresponding integral type called the underlying type
of the enum type. This underlying type must be able to represent all the
enumerator values defined in the enumeration. An enum declaration may
explicitly declare an underlying type of byte, sbyte, short, ushort, int, uint,
long or ulong. Note that char cannot be used as an underlying type. An enum
declaration that does not explicitly declare an underlying type has an
underlying type of int.
...

积分型定义为,

integral-type:

    sbyte

    byte

    short

    ushort

    int

    uint

    long

    ulong

    char