VB.NET Language in a Nutshell, Second Edition

Name

MyBase Keyword

Syntax

MyBase

Description

Provides a reference to the base class from within a derived class. If you want to call a member of the base class from within a derived class, you can use the syntax:

MyBase.MemberName

where MemberName is the name of the member. This will resolve any ambiguity if the derived class also has a member of the same name.

Rules at a Glance

• MyBase will call through the chain of inherited classes until it finds a callable implementation. For example, in the code:

  Public Class CTestClass
  ...
  End Class
  
  Public Class CTestClass2
     Inherits CTestClass
  
     Public Function ShowType(  ) As Type
        Return Mybase.GetType
     End Function
  End Class

  the call to ShowType is eventually resolved as a call to Object.GetType, since all classes are ultimately derived from the Object class.

• MyBase cannot be used to call Private class members.

• MyBase cannot be used to call base class members marked as MustOverride.

Programming Tips and Gotchas

• MyBase is commonly used to call back into the overridden member from the member that overrides it in the derived class.

• The MyBase keyword can be used to call the constructor of the base class to instantiate a member of that class, as in:

  MyBase.New(...)

VB.NET/VB 6 Differences

The MyBase keyword is new to VB.NET.