6 - Controls

Abstract

Creating windows and dialogue boxes is the first stage in the development of any application. The next stage is to add items to each window so that it has some practical functions. This chapter discusses the concept of controls—the buttons, list boxes, and other features that are added to any standard Windows application. It is in the creation of controls that the distinction between dialogue boxes and windows becomes important. The controls on a dialogue box are defined in the resource file. As such, they are not necessarily objects in the true sense and may appear on the dialogue box as a result of direct calls to the Windows functions. The controls on a window are objects, instances of some class, and are treated by Windows as child windows. The Visual Basic approach to controls is almost identical to that of App Studio for Visual C++. Visual Basic offers a few more controls in the tool palette; however, other than that the actions required for creating, deleting, moving, and copying controls are the same as those of C++.