.net - 如何覆盖类中属性的 .ToString

Question

我确实首先搜索了这个并且有一些类似的帖子，但我找不到我的答案。 :(

假设我有一个类:

Public Class ND
    Private mNumsDrawn = New List(Of Integer)

    Public Sub New(ByVal vNum As Integer)
        For i = 1 To vNum
            mNumsDrawn.Add(0)
        Next
    End Sub

    Public Property NumsDrawn As List(Of Integer)
        Get
            Return mNumsDrawn
        End Get
        Set(ByVal value As List(Of Integer))
            mNumsDrawn = value
        End Set
    End Property
End Class

我想覆盖属性 NumsDrawn 的 .ToString。

如果我将 .ToString 覆盖放在类中，那么它当然会覆盖类的 .ToString。我可以用它来输出列表中的所有数字，但我想更改抽奖中一个数字的输出。

Dim MyDraw = New ND(6)

MsgBox(MyDraw.ToString)

但是我想要的是这样的..

MsgBox(MyDraw.NumsDrawn(1).ToString)

谢谢!

Answer 1

我不确定您为什么要对 Integer 类型进行自定义 .ToString() 覆盖...但是...

一个简单的方法是将 NumsDrawn 从 List(Of Integer) 更改为 List(Of NumClass)然后在那个类上覆盖.ToString:

Public Class ND
    Private mNumsDrawn As List(Of NumClass) = New List(Of NumClass)

    Public Sub New(ByVal vNum As Integer)
        For i = 1 To vNum
            mNumsDrawn.Add(New NumClass(0))
        Next
    End Sub

    Public Property NumsDrawn As List(Of NumClass)
        Get
            Return mNumsDrawn
        End Get
        Set(ByVal value As List(Of NumClass))
            mNumsDrawn = value
        End Set
    End Property
End Class

Public Class NumClass
    Public Property Value As Integer
    Public Sub New(value As Integer)
        Me.Value = value
    End Sub
    Public Overrides Function ToString() As String
        Return "Here is my formatted value: " & Me.Value
    End Function
End Class

用法:

    Dim myND As New ND(99)
    Debug.WriteLine(myND.NumsDrawn(6).ToString()) 'outputs:- Here is my formatted value: 0