How does the tooltip control enhance all controls on the form with a new property?

Question

When answering another question I started to wonder how I could Add new properties to all controls in a form just like the ToolTip-control does.

For example I could use that to Add a "IsDirty"-flag to all textboxes just by adding the component to the form and it would handle this for every textbox.

When adding the tooltip-control to the form all controls magically gets a new property "Tooltip on tooltip1" that can be set both programatically and in design view.

I want to be able to do my own enhancer like that.

Answer 1

It's an Extender Provider.