Public Sub New()
MyBase.New()
Form1 = Me
'This call is required by the Win Form Designer.
InitializeComponent()
'TODO: Add any initialization after the InitializeComponent() call
End Sub
'Form overrides dispose to clean up the component list.
Public Overrides Sub Dispose()
MyBase.Dispose()
components.Dispose()
End Sub
#Region " Windows Form Designer generated code "
.......
#End Region
Protected Sub Form1_Click( ByVal sender As Object,
ByVal e As System.EventArgs)
Dim crag As New Teacher("Crag", 38, 45000)
crag.modifyName("Crag Clinton")
MessageBox.Show( "AGE: " + str(crag.age) + ", SALARY: "
+ str(crag.salary))
End Sub
End Class

因为name是Person类别的私有资料，在子类别Teacher的modifyName()里不能使用此资料名称，所以错了。如果将Person类别定义为﹕

'ex03.bas
Imports System.ComponentModel
Imports System.Drawing
Imports System.WinForms
'---------------------------------------------------------
Class Person
Protected name As String
Public age As Integer

Public Sub New(ByVal na As String, ByVal a As Integer)
name = na
age = a
End Sub
Public Function GetName() As String
GetName = name
End Function
End Class

Class Teacher
Inherits Person

Public salary As Single
Public Sub New(ByVal na As String, ByVal a As Integer, ByVal sa As Single)
MyBase.New(na, a)
salary = sa
End Sub
Public Sub modifyName(ByVal na As String)
name = na
End Sub
End Class
'--------------------------------------------------------
Public Class Form1
Inherits System.WinForms.Form

Public Sub New()
MyBase.New()
Form1 = Me
'This call is required by the Win Form Designer.
InitializeComponent()
'TODO: Add any initialization after the InitializeComponent() call
End Sub
'Form overrides dispose to clean up the component list.
Public Overrides Sub Dispose()
MyBase.Dispose()
components.Dispose()
End Sub
#Region " Windows Form Designer generated code "
......
#End Region
Protected Sub Form1_Click( ByVal sender As Object,
ByVal e As System.EventArgs)
Dim crag As New Teacher("Crag", 38, 45000)
crag.modifyName("Crag Clinton")
MessageBox.Show( "AGE: " + str(crag.age) + ", NAME: "
+ crag.GetName())
End Sub
End Class

此程序输出：
AGE: 42, NAME: Crag Clinton

此时﹐name为家族公用之资料﹐凡是Person之子孙类别皆可取用之。但家族外之程序（如 Form1_Click()程序）仍不得直接使用之。如果上述定义改为﹕

Class Person
Protected name As String
Private salary As Decimal
Public age As Integer

Public Sub New(ByVal na As String, ByVal a As Integer)
name = na
age = a
End Sub
End Class

(编辑:aniston)