This is what I did. What I've done differently is use the same name and the new keyword on the "consuming" enum. Since the name of the enum is the same, you can just mindlessly use it and it will be right. Plus you get intellisense. You just have to manually take care when setting it up that the values are copied over from the base and keep them sync'ed. You can help that along with code comments. This is another reason why in the database when storing enum values I always store the string, not the value. Because if you are using automatically assigned increasing integer values those can change over time.

// Base Class for balls 
public class Ball
{
    // keep synced with subclasses!
    public enum Sizes
    {
        Small,
        Medium,
        Large
    }
}

public class VolleyBall : Ball
{
    // keep synced with base class!
    public new enum Sizes
    {
        Small  = Ball.Sizes.Small,
        Medium = Ball.Sizes.Medium,
        Large  = Ball.Sizes.Large,
        SmallMedium,
        MediumLarge,
        Ginormous
    }
}

枚举不能从其他枚举派生，只能从int、uint、short、ushort、long、ulong、byte和sbyte派生。

就像Pascal说的，你可以使用其他枚举的值或常量来初始化一个枚举值，但仅此而已。

这是不可能的。枚举不能从其他枚举继承。事实上，所有枚举都必须从System.Enum继承。c#允许语法改变枚举值的底层表示，这看起来像继承，但实际上它们仍然继承自System.enum。

详细信息请参见CLI规范的8.5.2节。来自规范的相关信息

所有枚举必须从System派生。枚举 因此，所有枚举都是值类型，因此是密封的

上述使用int常量类的解决方案缺乏类型安全。也就是说，你可以发明一些在课堂上没有定义的新值。 此外，举例来说，编写以这些类之一作为输入的方法是不可能的。

你需要写

public void DoSomethingMeaningFull(int consumeValue) ...

但是，在以前的Java中有一个基于类的解决方案，当时没有可用的枚举。这提供了几乎类似枚举的行为。唯一需要注意的是，这些常量不能在switch语句中使用。

public class MyBaseEnum
{
    public static readonly MyBaseEnum A = new MyBaseEnum( 1 );
    public static readonly MyBaseEnum B = new MyBaseEnum( 2 );
    public static readonly MyBaseEnum C = new MyBaseEnum( 3 );

    public int InternalValue { get; protected set; }

    protected MyBaseEnum( int internalValue )
    {
        this.InternalValue = internalValue;
    }
}

public class MyEnum : MyBaseEnum
{
    public static readonly MyEnum D = new MyEnum( 4 );
    public static readonly MyEnum E = new MyEnum( 5 );

    protected MyEnum( int internalValue ) : base( internalValue )
    {
        // Nothing
    }
}

[TestMethod]
public void EnumTest()
{
    this.DoSomethingMeaningful( MyEnum.A );
}

private void DoSomethingMeaningful( MyBaseEnum enumValue )
{
    // ...
    if( enumValue == MyEnum.A ) { /* ... */ }
    else if (enumValue == MyEnum.B) { /* ... */ }
    // ...
}

忽略base是保留字的事实，你不能继承enum。

你能做的最好的事情就是这样:

public enum Baseenum
{
   x, y, z
}

public enum Consume
{
   x = Baseenum.x,
   y = Baseenum.y,
   z = Baseenum.z
}

public void Test()
{
   Baseenum a = Baseenum.x;
   Consume newA = (Consume) a;

   if ((Int32) a == (Int32) newA)
   {
   MessageBox.Show(newA.ToString());
   }
}

因为它们都是相同的基类型(即:int)，你可以将一个类型的实例的值赋给另一个类型，这就是强制转换。虽然不理想，但很有效。

你可以通过类实现你想要的:

public class Base
{
    public const int A = 1;
    public const int B = 2;
    public const int C = 3;
}
public class Consume : Base
{
    public const int D = 4;
    public const int E = 5;
}

现在你可以像使用枚举一样使用这些类:

int i = Consume.B;

更新(在您更新问题后):

如果你将相同的int值赋给现有枚举中定义的常量，那么你可以在枚举和常量之间进行类型转换，例如:

public enum SomeEnum // this is the existing enum (from WSDL)
{
    A = 1,
    B = 2,
    ...
}
public class Base
{
    public const int A = (int)SomeEnum.A;
    //...
}
public class Consume : Base
{
    public const int D = 4;
    public const int E = 5;
}

// where you have to use the enum, use a cast:
SomeEnum e = (SomeEnum)Consume.B;