.net - 派生类的泛型版本可以使用泛型类型重写基方法吗？

Question

考虑:

Public MustInherit Class Column
    Public ReadOnly Property ReturnSomethingUseful() As Object
        Get
             'return something useful
        End Get
    End Property
End Class

Public Class TypedColumn(Of T)
    Inherits Column

    Public Overrides ReadOnly Property ReturnSomethingUseful() As T
        Get
             'return the same something useful, but as type T
             Return MyBase.ReturnSomethingUseful()
        End Get
    End Property
End Class

但这会出现以下错误:

Public Overrides Function ReturnSomethingUseful(sValue As String) As Boolean' cannot override 'Public Overridable Function ReturnSomethingUseful(sValue As String) As Object' because they differ by their return types.

我承认你不能这样做，但我希望能够保留我尝试要做的事情的语义，即拥有一个处理与Object，但派生类中的类型化版本知道特定类型T。有什么办法可以实现这一点吗？

Answer 1

是的，有:使用 Shadows修改器

Public Shadows ReadOnly Property ReturnSomethingUseful() As T
    Get
         'return the same something useful, but as type T
         Return MyBase.ReturnSomethingUseful()
    End Get
End Property