Basic Class Concepts

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In case you are not yet familiar with using class modules to build custom objects, this section covers the basics of adding a class to your project, creating an instance of a class in memory, and constructing properties and methods.

In This Section

  • What Is a Class?
    A class is a definition for an object. It contains information about how an object should behave, including its name, methods, properties, and events.
  • Adding a Class Module
    To add a class module to your Microsoft® Visual Basic® for Applications (VBA) project, click Class Module on the Insert menu in the Visual Basic Editor.
  • Creating a New Instance of a Class
    To work with a custom object from code, you first create a new instance of the class that defines the object.
  • The Instancing Property
    This property specifies whether the class module should be visible from another project when you have set a reference to the project that contains the class module.
  • Matters of Scope
    When designing a custom object, you should think carefully about the object's scope and lifetime within the project, as well as that of its properties and methods.
  • Creating Simple Properties with Variables
    The simplest way to create a property for a custom object is to add a public module-level variable to the class module.
  • Creating Methods
    Public module-level variables in a class module function as properties of an object.
  • Custom Classes and Objects
    If you have never used class modules to build custom objects before, this section covers the concepts that you must understand to design, build, and use custom objects with their own methods and properties.
  • Why Build Your Own Objects?
    Build entire custom object models that involve complex code behind the scenes, but that present a relatively simple and intuitive object syntax to the programmer.
  • Creating Property Procedures
    Public module-level variables in a class module function as properties of an object.
  • Creating Events and Event Procedures
    Take advantage of simple to create events procedures and use ThisDocument, ThisWorkbook, or SheetN objects.
  • Extending Objects Through Interfaces
    Suppose that in the process of designing your application, you decide that you want to create several objects that are closely related, and, in fact, require at least some of the same properties and methods.
  • Designing Object Models
    When you design an object model, you are taking abstract processes and imposing concrete relationships upon them.
  • Creating Custom Objects for Web Pages
    There are two ways to create objects for Web pages that are similar to custom objects created in Microsoft® Visual Basic® for Applications (VBA): by creating scriptlets, and by using Microsoft® Internet Explorer version 5 and later behaviors.