.NET Windows® Forms Custom Controls

Control Concepts

Regardless of the type of control being developed, its use should be immediately obvious to the user of the control. After all, if the user doesn't know what the control does, then the control serves no valid use. In addition, users expect some basic concepts to be universal among all controls. For example, users expect a left mouse click to result in an action.

Consider a menu, a toolbar, and a command button. Although each control looks different, users expect that when they left-click the control, some action will take place within the application. The action is, of course, application specific; however, the control's behavior is common among all applications. This common functionality is the cornerstone of Windows development ...