Most Delphi programmers are probably familiar with using existing components, but at times it can also be useful to write your own components or to customize existing ones. One of the most interesting aspects of Delphi is that creating components is not much more difficult than writing programs. For this reason, even though this book is intended for Delphi application programmers and not Delphi tool writers, this chapter will discuss creating components and introduce Delphi add-ins, such as component and property editors.
This chapter gives you an overview of writing Delphi components and presents some examples. There is not enough space to present very complex components, but the ideas I've included cover all the basics and will get you started.
You'll find more information about writing components in Chapter 17, "Writing Database Components," including how to build data-aware components.