Creating Components

Go Up to Introduction to component creation Index

A component can be almost any program element that you want to manipulate at design time. Creating a component means deriving a new class from an existing one. You can derive a new component in several ways:

• Modifying Existing Controls
• Creating Original Controls
• Creating Graphic Controls
• Subclassing Windows Controls
• Creating Nonvisual Components

The following table summarizes the different kinds of components and the classes you use as starting points for each.

Component creation starting points :

To do this	Start with this type
Modify an existing component	Any existing component, such as TButton or TListBox, or an abstract component type, such as TCustomListBox
Create a windowed control	TWinControl
Create a graphic control	TGraphicControl
Subclassing a control	Any Windows control
Create a nonvisual component	TComponent

You can also derive classes that are not components and cannot be manipulated on a form, such as TRegIniFile and TFont.

See Also

• Understanding the Component Library
• Components and Classes
• What Goes into a Component
• Creating a New Component
• Testing Uninstalled Components