c# - 类修饰符

我从来没有主动学习正确的类修饰符，因为它一直是“很高兴”但不是“需要”。

我可以做Dim F as New Person.FavoriteFoodsList令我很烦。

我使用哪个类修饰符，以便我的Person类可以利用FavoriteFoodsList，但Person之外的任何实例都不能实例化FavoriteFoodsList？

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    Dim P As New Person
    P.FavoriteFoods.Add("Pizza")
    Dim F As New Person.FavoriteFoodsList 'How do I prevent this
End Sub
Public Class Person
    Public FavoriteFoods As New FavoriteFoodsList
    Public Class FavoriteFoodsList
        Inherits Collections.Generic.List(Of String)
    End Class
End Class

最佳答案

我建议您为类定义一个公共接口，然后将实现标记为私有。

Public Interface IFavoriteFoodsList
    Inherits Collections.Generic.IList(Of String)
    ' Define other public api methods'
End Interface

Public Class Person
    Public FavoriteFoods As IFavoriteFoodsList = New FavoriteFoodsList
    Private Class FavoriteFoodsList
        Inherits Collections.Generic.List(Of String)
        Implements IFavoriteFoodsList
    End Class
End Class