Introduction

The article assumes that you're familiar with Visual Basic .NET and the Visual Studio .NET Windows Forms designer.

When developing Windows Forms controls it is often useful to provide your own, drop-down type editors for some of the control's properties. Custom type editors provide for richer design-time experience and they might be the deciding factor whether your users like your controls or not.

If you decide to create your own drop-down type editor, it should, presumably, follow the same behavioral pattern exposed by the built-in drop-down editors. Let's take the Anchor property as an example. A typical design-time user interaction with the property is as follows:

• The user selects the Anchor property in the property grid and clicks the down-arrow button to the right of the property's cell.
• A nice graphical control is dropped down allowing the user to either click the edges by the mouse or use the arrow keys to highlight an edge and the SPACEBAR key to select / deselect it.
• The user presses the ENTER key or clicks outside of the drop-down control for accepting the changes. In order to cancel the changes, the user presses the ESC key.

Pretty intuitive!

So what does it take to replicate the above-mentioned behavior?