0

假设我有一个这样的数据库结构:

create table Product(id int not null identity,Name varchar(30))
INSERT INTO Product VALUES ('ProductA')
INSERT INTO Product VALUES ('ProductB')

和这样的类结构:

    Imports System.Data.SqlClient

Public Class Product

    Protected ProductName As String

    Public Overridable Sub Display()

    End Sub

End Class

Public Class ProductA
    Inherits Product

    Public Sub New(ByVal product As String)
        ProductName = product
    End Sub

    Public Overrides Sub Display()
        'Specific logic to display product A
    End Sub

End Class

Public Class ProductB
    Inherits Product

    Public Sub New(ByVal product As String)
        ProductName = product
    End Sub

    Public Overrides Sub Display()
        'Specific logic to display product B
    End Sub

End Class

Public Class Form1

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Dim p1 As Product
        Dim p2 As Product

        p1 = New ProductA("ProductA")
        p2 = New ProductB("ProductB")
        p1.Display()
        p2.Display()
    End Sub
End Class

有一个属性(产品)可以标识该类与哪个产品相关。这对我来说看起来不正确。有没有更好的建模方法?这类似于 NHibernate 的鉴别器概念(在这种情况下我没有使用 NHibernate)。

4

1 回答 1

0

随着您的最新更改,您应该将构造函数移动到基类。除此之外,设计还不错。

Public Class Product

    Protected ProductName As String

    Public Sub New(ByVal product As String)
        ProductName = product
    End Sub

    Public Overridable Sub Display()

    End Sub

End Class

Public Class ProductA
    Inherits Product

    Public Overrides Sub Display()
        'Specific logic to display product A
    End Sub

End Class

此外,在您的声明中,您可以使用继承的类:

Dim p1 As ProductA
Dim p2 As ProductB
于 2013-02-11T21:23:03.767 回答