VB.Net Tutorial/Data Type/CType
Версия от 19:40, 26 мая 2010; (обсуждение)
Use CType to convert from derived class to base class
<source lang="vbnet">public class Test
public Shared Sub Main Dim people As New Collection people.Add(New Employee("A")) people.Add(New Customer("B")) Dim emp As Employee For Each person As Object In people If TypeOf person Is Employee Then emp = CType(person, Employee) Console.WriteLine(emp.Name) ElseIf TypeOf person Is Customer Then Console.WriteLine(CType(person, Customer).Name) End If Next person End Sub
End class
Public Class Employee
Public Name As String Public Sub New(ByVal new_name As String) Name = new_name End Sub Public Overridable Function IsManager() As Boolean Return False End Function
End Class Public Class Customer
Public Name As String Public Sub New(ByVal new_name As String) Name = new_name End Sub
End Class Public Class Manager
Inherits Employee Public Sub New(ByVal new_name As String) MyBase.new(new_name) End Sub Public Overrides Function IsManager() As Boolean Return True End Function
End Class</source>
A B