|
> End Function
Public Overridable Sub Display()
Messagebox.Show("Name: " + name + " Age: " + str(age))
End Sub
End Class
Public Class Teacher
Inherits Person
Private salary As Decimal
Public Overloads Sub SetValue( ByVal na As String, ByVal a As Integer, ByVal
sa As Decimal)
SetValue(na, a)
salary = sa
End Sub
Public Overrides Sub Display()
MyBase.Display()
Messagebox.Show("Salary: " + str(salary))
End Sub
End Class
Public Class Student
Inherits Person
Private student_number As Integer
Public Overloads Sub SetValue( ByVal na As String, ByVal a As Integer, ByVal
no As Integer)
SetValue(na, a)
student_number = no
End Sub
Public Overrides Sub Display()
MyBase.Display()
Messagebox.Show("StudNo: " + str(student_number))
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 x As New Person()
x.SetValue("Alvin", 32)
Dim y As New Student()
y.SetValue("Tom", 36, 11138)
x.Display()
y.Display()
End Sub
End Class
此程序输出﹕
Name: Alvin Age: 32
Name: Tom Age: 36
StudNo: 11138
此时﹐Student 类别含有两个SetValue()程序，一个是从Person类别继承而来，另一个是自行定义的。如果上述Form1_Click()内的指令更改如下：
Dim y As New Student()
y.SetValue("Tom", 36, 5000.25) ''''Error!
y.Display()
虽然SetValue("Tom", 36, 5000.25)合乎Teacher的SetValue()程序的参数，但是Student并非Person的子类别，没有继承Student的SetValue()，所以错了。n
上一页 [1] [2] [3] [4]
没有相关教程
| 
注：本站部分文章源于互联网，版权归原作者所有！如有侵权，请原作者与本站联系，本站将立即删除！ 本站文章除特别注明外均可转载，但需注明出处！ [MinTao学以致用网] 
