Base Classes Available in Visual FoxPro (129790)

SUMMARY

All Visual FoxPro base classes recognize a minimum set of events and properties. You can create objects or derive subclasses from most of the Visual FoxPro base classes, but not all.

This article lists the Visual FoxPro base classes, indicates whether or not each class can be subclassed, lists the minimum event set for Visual FoxPro base classes, and lists the minimum property set for Visual FoxPro base classes.

MORE INFORMATION

Visual FoxPro Base Classes That Can Be Subclassed

The following Visual FoxPro Classes are not an integral part of a parent container, so they can be subclassed in the Class Designer:

  check box        EditBox        list box              Shape
  Column (1)       Form           OLEBoundControl       Spinner
  CommandButton    FormSet        OLEContainerControl   text box
  CommandGroup     Grid           Timer                 ComboBox
  OptionGroup      ToolBar        Container             Image Control
  Label            PageFrame      Custom                Line

Visual FoxPro Base Classes That Cannot Be Subclassed

The following Visual FoxPro Classes are an integral part of a parent container, so they cannot be subclassed in the Class Designer:

  Header
  OptionButton
  Page
  Separator

Base Class Minimum Event Set

All Visual FoxPro base classes recognize the following minimum set of events:

  Event   - Description
-----------------------
  Init    - Invoked when the object is created.
  Destroy - Invoked when the object is released from memory.
  Error   - Invoked when an error occurs in event or method procedures
            of the class.

Base Class Minimum Property Set

All Visual FoxPro base classes have the following minimum set of properties:

  Property     -  Description

  Class        -  What type of class it is.

  BaseClass    -  The base class it was derived from, such as Form,
                  Commandbutton, Custom, and so on.

  ClassLibrary -  The class library the class belongs to.

  ParentClass  -  The class the object was derived from. If the class was
                  derived directly from a Visual FoxPro base class, the
                  ParentClass property is the same as the BaseClass
                  property.

NOTE: Most of the information in this article is available under many different topics in the Visual FoxPro Help file.