In the Visual Basic environment, an ActiveX designer appears in a frame at design time, just as a form does. A frame is a container that looks like a window and defines window-like properties, methods, and events. Visual Basic creates and manages the frame, and the visual designer interacts with it through ActiveX interfaces. Within the frame, the ActiveX designer controls its own visual representation.
The following figure illustrates the frame for an ActiveX designer named CircleCoCtl1:
Visual Basic provides the frame window. Hosted within the frame's boundaries, CircleCoCtl1 implements its own window to control the look and feel of the user interface, either handling events itself or passing them on to Visual Basic.