Computer Programming Concepts and Visual Basic David I. Schneider

cedures that are available to all forms. To do so, select Add Module from the Project menu
and then double-click on the Module icon. A code window will appear with Module1 in the
title bar. Procedures created in this window with the Public keyword will be available to all
forms. To declare a variable that is available to all forms, declare it in the Module1 window,
but use the word Public instead of Dim. For instance, if the statement
Public person As String
appears in the Module1 code window, the variable person can be accessed anywhere in the program.
The contents of this code window are said to form a (Standard) code module. Project
Explorer shows the names of all forms and code modules and gives you access to the code
from any form or module. When a code module is selected, you can save it by choosing Save
Module As from the File menu. You add an existing code module to a program by choosing
Add File from the Project menu.
■ THE COMMON DIALOG CONTROL
The common dialog control does not initially appear in your Toolbox. To add the control, select
Components from the Project menu, click the Controls tab, and click on the check box to
the left of “Microsoft Common Dialog Control 6.0.” Then press the OK button. By convention,
names of common dialog boxes have the prefix dlg.
The common dialog control can produce each of the useful dialog boxes in Figures 10.13
through 10.17, thereby saving the programmer the trouble of designing custom dialog boxes
for these purposes. The common dialog control has no events, only methods and properties.
Actually, like the Timer control, the common dialog box control is invisible. However, when
you execute a statement of the form
CommonDialog1.Show_________
where the blank line is filled with Open, Save, Color, Font, or Printer, the specified dialog
box is produced. Table 10.1 gives the purposes of the various dialog boxes.
TABLE 10.1
The Different Types of Dialog Boxes
Type of Dialog box Purpose of Dialog Box
Open Determine what file to open
Save As Determine where and with what name to save a file
Color Select any available color
Font Select a font for the screen or printer
Print Help control the printer
FIGURE 10-13 An Open Common Dialog Box
Five Additional Objects 313