Teach Yourself Borland C++ in 14 Days - portal

NOTE
The C++Builder IDE Explored: Projects and Forms
resource script is compiled into an .RES file (the binary resource file), which then gets linked
to the .EXE by the linker. At runtime the dialog box is displayed either modally or modelessly,
depending on the dialog box’s intended purpose. When the dialog box is executed, Windows
loads the dialog box resource from the executable file, builds the dialog box, and displays it.
A modal dialog box is one that must be dismissed before the user can
continue using the application. The main window of an application is
disabled while this type of dialog box is open. Most dialog boxes are
modal. The Compile Status dialog box in C++Builder is an example of
a modal dialog box.
A modeless dialog box is one that allows the user to continue to work
with the application while the dialog box is displayed. The Find dialog
box in some word-processing programs is an example of a modeless
dialog box.
Now, with that background information on how dialog boxes are handled in a traditional
Windows program, let’s take a look at how C++Builder handles dialog boxes.
Dialog Boxes in C++Builder
In C++Builder, a dialog box is simply another form. You create a dialog box just like you do
a main window form or any other form. To prevent the dialog box from being sized, you can
change the BorderStyle property to bsDialog or bsSingle. If you use bsDialog, your dialog
box will have only the close box on the title bar, which is traditional for dialog boxes. Other
than that, you don’t have to do anything special to get a form to behave like a dialog box. All
C++Builder forms have tabbing support built in. You can set the tab order by altering the
TabOrder property of the individual controls on the dialog box.
A C++Builder dialog box (any C++Builder form, actually) is modal or modeless, depending
on how it is displayed. To execute a modal dialog box, you call the ShowModal() method of
TForm. To create a modeless dialog box, you call the Show() method.
Let’s add an About box to the multiple-forms project we created earlier. If you don’t have that
project open, choose File | Open from the main menu or click the Open Project button on
the toolbar and locate the file (you should have saved it with the project name Multiple).
189
6