VB.Net Tutorial/Class Module/MustOverride — различия между версиями
Admin (обсуждение | вклад) м (1 версия) |
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Версия 16:40, 26 мая 2010
MustOverride method
Option Strict On
Imports System
MustInherit Public Class Control
Public Sub New(top As Integer, left As Integer)
Me.top = top
Me.left = left
End Sub
Public MustOverride Sub DrawControl( )
Protected top As Integer
Protected left As Integer
End Class
Public Class Label
Inherits Control
Public Sub New(top As Integer, left As Integer, contents As String)
MyBase.New(top, left)
listBoxContents = contents
End Sub
Public Overrides Sub DrawControl( )
Console.WriteLine("Writing string to the listbox: {0}", listBoxContents)
End Sub
Private listBoxContents As String
End Class
Public Class Button
Inherits Control
Public Sub New(top As Integer, left As Integer)
MyBase.New(top, left)
End Sub
Public Overrides Sub DrawControl( )
Console.WriteLine("Drawing a button at {0}, {1}" + ControlChars.Lf, top, left)
End Sub
End Class
Public Class Tester
Shared Sub Main( )
Dim winArray(3) As Control
winArray(0) = New Label(1, 2, "A")
winArray(1) = New Label(3, 4, "B")
winArray(2) = New Button(5, 6)
Dim i As Integer
For i = 0 To 2
winArray(i).DrawControl( )
Next i
End Sub "Main
End Class "Tester
Writing string to the listbox: A Writing string to the listbox: B Drawing a button at 5, 6
MustOverrides MustInherit
public class MustOverrideMustInherit
public Shared Sub Main
Dim Emp1 As New Employee()
Emp1.Name = "B"
Console.WriteLine(GetName(Emp1))
Dim Cus1 As New Customer()
Cus1.Name = "T"
Console.WriteLine(GetName(Cus1))
End Sub
Public Shared Function GetName(ByVal p As Person) As String
Return p.Name
End Function
End class
Public MustInherit Class Person
Public MustOverride Property Name() As String
End Class
Public Class Employee
Inherits Person
Private m_Name
Public Overrides Property Name() As String
Get
Return m_Name
End Get
Set(ByVal Value As String)
m_Name = Value
End Set
End Property
End Class
Public Class Customer
Inherits Person
Private m_Name
Public Overrides Property Name() As String
Get
Return m_Name
End Get
Set(ByVal Value As String)
m_Name = Value
End Set
End Property
End Class
B T