Not all objects in Visual Basic are visible and displayed to the user. Neither are all object windows. Visual Basic contains system objects that are available to use, although they are not displayed in the toolbox, including the following:
- App – This object stores information about the application, including its name, path (where it is stored), and the files it requires. This object can also activate an application.
- clipboard – This object is a temporary storage location. It allows text, graphics and computer code to be transferred from one part of an application to another part or from one application to another.
- screen – This object references the entire video display screen. It manipulates the size and placement of forms on the screen.
- Debug – This object permits the display of information about a program while it is being developed.
- Printer – This object determines how text and graphics are printed on a page and how output is sent to the printer.
These are system objects because the Windows operating system keeps information about each one. For example, when you set up Windows, you must designate the computer printer to be used to send output to the printer. When a specific printer is selected, Windows stores information about its makeup, such as the paper width and length. In Visual Basic, you never have to use your printer’s name in a program. Instead, you can instruct your printer to print directly by using the Printer object.
System objects will become important later. For now, you should simply be aware that they exist and of what they do.