引用本文:

This is actually by design. There seems to be no good reason to inherit a static class. It has public static members that you can always access via the class name itself. The only reasons I have seen for inheriting static stuff have been bad ones, such as saving a couple of characters of typing. There may be reason to consider mechanisms to bring static members directly into scope (and we will in fact consider this after the Orcas product cycle), but static class inheritance is not the way to go: It is the wrong mechanism to use, and works only for static members that happen to reside in a static class. (Mads Torgersen, C# Language PM)

来自9频道的其他观点

Inheritance in .NET works only on instance base. Static methods are defined on the type level not on the instance level. That is why overriding doesn't work with static methods/properties/events... Static methods are only held once in memory. There is no virtual table etc. that is created for them. If you invoke an instance method in .NET, you always give it the current instance. This is hidden by the .NET runtime, but it happens. Each instance method has as first argument a pointer (reference) to the object that the method is run on. This doesn't happen with static methods (as they are defined on type level). How should the compiler decide to select the method to invoke? (littleguru)

作为一个有价值的想法，littleuru对这个问题有一个部分的“变通方案”:单例模式。

引用本文:

This is actually by design. There seems to be no good reason to inherit a static class. It has public static members that you can always access via the class name itself. The only reasons I have seen for inheriting static stuff have been bad ones, such as saving a couple of characters of typing. There may be reason to consider mechanisms to bring static members directly into scope (and we will in fact consider this after the Orcas product cycle), but static class inheritance is not the way to go: It is the wrong mechanism to use, and works only for static members that happen to reside in a static class. (Mads Torgersen, C# Language PM)

来自9频道的其他观点

Inheritance in .NET works only on instance base. Static methods are defined on the type level not on the instance level. That is why overriding doesn't work with static methods/properties/events... Static methods are only held once in memory. There is no virtual table etc. that is created for them. If you invoke an instance method in .NET, you always give it the current instance. This is hidden by the .NET runtime, but it happens. Each instance method has as first argument a pointer (reference) to the object that the method is run on. This doesn't happen with static methods (as they are defined on type level). How should the compiler decide to select the method to invoke? (littleguru)

作为一个有价值的想法，littleuru对这个问题有一个部分的“变通方案”:单例模式。

虽然可以通过继承的类名访问“继承的”静态成员，但静态成员并不是真正继承的。这就是为什么它们不能是虚拟的或抽象的，也不能被覆盖的部分原因。在你的例子中，如果你声明了一个Base.Method()，编译器无论如何都会将对Inherited.Method()的调用映射回Base.Method()。您也可以显式地调用Base.Method()。您可以编写一个小测试，并使用Reflector查看结果。

所以…如果不能继承静态成员，并且静态类只能包含静态成员，那么继承静态类又有什么用呢?

你可以做的一个解决方法是不使用静态类，而是隐藏构造函数，这样类的静态成员是类外部唯一可访问的东西。结果是一个可继承的“静态”类:

public class TestClass<T>
{
    protected TestClass()
    { }

    public static T Add(T x, T y)
    {
        return (dynamic)x + (dynamic)y;
    }
}

public class TestClass : TestClass<double>
{
    // Inherited classes will also need to have protected constructors to prevent people from creating instances of them.
    protected TestClass()
    { }
}

TestClass.Add(3.0, 4.0)
TestClass<int>.Add(3, 4)

// Creating a class instance is not allowed because the constructors are inaccessible.
// new TestClass();
// new TestClass<int>();

不幸的是，由于“by-design”语言限制，我们无法做到:

public static class TestClass<T>
{
    public static T Add(T x, T y)
    {
        return (dynamic)x + (dynamic)y;
    }
}

public static class TestClass : TestClass<double>
{
}

当我试图对第三方库编写IComparer<T>实现时，我遇到了这个问题，其中T是嵌入在类中的enum，如下所示:

public class TheClass
{
    public enum EnumOfInterest
    {
    }
}

但是因为枚举是在第三方库类中定义的，所以我不能编写比较器，因为下面给出了“不能扩展列表”错误:

public class MyComparer : IComparer<TheClass.EnumOfInterest>
{
}

我甚至没有扩展静态类——我只是实现类中定义的枚举的比较器。

可以这样考虑:你通过类型名访问静态成员，就像这样:

MyStaticType.MyStaticMember();

如果你要从这个类继承，你必须通过新的类型名来访问它:

MyNewType.MyStaticMember();

因此，在代码中使用时，新项与原始项没有关系。没有办法利用任何继承关系来处理多态性之类的事情。

也许您只是想扩展原始类中的一些项。在这种情况下，没有什么可以阻止您在一个全新的类型中使用原始类型的成员。

也许您希望向现有静态类型添加方法。您已经可以通过扩展方法做到这一点。

也许您希望能够在运行时将静态类型传递给函数，并调用该类型的方法，而不需要确切地知道该方法的功能。在这种情况下，您可以使用接口。

所以，最终你不会从继承静态类中获得任何东西。