Question

我是VB.net的新手，我无法编译这段代码，我不明白为什么。

MustInherit Class Poligono

    Protected p_cant_Lados As Integer
    Public Property cant_Lados() As Integer
        Get
            Return p_cant_Lados
        End Get
        Set(ByVal value As Integer)
            p_cant_Lados = value
        End Set
    End Property

    Public MustOverride Function obtenerPerimetro()
    Public MustOverride Function cargarLados()

End Class

Public Class Triangulo
    Inherits Poligono

    Private lado1 As Integer
    Private lado2 As Integer
    Private lado3 As Integer

    Public Function cargarLados() As Object
        Return 1
    End Function

    Public Function obtenerPerimetro() As Object
        Return 1
    End Function

End Class

错误2'Triangulo'不能继承“Poligono”类，因为它扩展基类的访问权限部件。 c：\ users \ win7 \ documents \ visual studio 2013 \ Projects \ WindowsApplication1 \ WindowsApplication1 \ Form1.vb 33 14 WindowsApplication1

谢谢！

Answer 1

默认情况下，classes declared at the namespace level get Friend access level。因此Poligono是Friend Class。一般公众可能无法看到Friend课程。

更改

MustInherit Class Poligono

到

Public MustInherit Class Poligono

Answer 2

两件事：

您必须使用As

添加返回类型

Public MustOverride Function obtenerPerimetro() As Object
Public MustOverride Function cargarLados() As Object

您必须将Overrides添加到覆盖抽象基类的方法

Public Overrides Function cargarLados() As Object
    Return 1
End Function

Public Overrides Function obtenerPerimetro() As Object
    Return 1
End Function

VB.net无法继承

2 个答案: