Sams Teach Yourself Visual Basic 6 in 24 Hours

By Greg Perry

• Table of Contents
  • Copyright
  • About the Author
  • Acknowledgments
  • Introduction
  • Who Should Read This Book
  • What This Book Will Do for You
  • Can This Book Really Teach Visual Basic in 24 Hours?
  • What You Need
  • Files on the Visual Basic Distribution CD-ROM
  • Conventions Used in This Book
  • Enough! Time Is Ticking!
  • Part I: Introducing Visual Basic
  • Hour 1. Visual Basic at Work
  • Hour 2.Analyzing Visual Basic Programs
  • Hour 3.Controls and Properties
  • Hour 4.Examining Labels, Buttons, and Text Boxes
  • Part II: Coding the Details
  • Hour 5.Putting Code into Visual Basic
  • Hour 6.Message and Input Boxes
  • Hour 7.Making Decisions
  • Hour 8.Visual Basic Looping
  • Part III:Putting Code to Work
  • Hour 9.Combining Code and Controls
  • Hour 10.List Boxes and Data Lists
  • Hour 11.Additional Controls
    • Option Buttons
    • Frames and Option Buttons
    • Check Boxes
    • Scrollbars
    • VB's Clock: The Timer Control
    • Summary
    • Q&A
    • Workshop
  • Hour 12.Dialog Box Basics
  • Part IV:Programming with Data
  • Hour 13.Modular Programming
  • Hour 14.Built-In Functions Save Time
  • Hour 15.Visual Basic Database Basics
  • Hour 16.Printing with Visual Basic
  • Part V:Sprucing Up Programs
  • Hour 17.Menus and Visual Basic
  • Hour 18.The Graphic Image Controls
  • Hour 19.Toolbars and More Graphics
  • Hour 20.Writing Correct Applications
  • Part VI:Advancing Visual Basic Applications
  • Hour 21.Visual Basic and ActiveX
  • Hour 22.Object Basics
  • Hour 23.Distributing Your Applications
  • Hour 24.Online Visual Basic
  • Part VII:Appendixes
  • Appendix A.Operator Precedence
  • Appendix B.Answers
  • Appendix C.Using the CD-ROM

Q&A

1. Can I program check boxes to be mutually exclusive or do I have to use option buttons?

   Check boxes are not mutually exclusive by design. Option buttons are. Therefore, a Visual Basic application's user can only select one option button at a time within any one frame or on the form. If you want to change the behavior of check boxes and make them act like option buttons, be warned that you are giving your users mixed signals. Users are familiar with being able to select as many check boxes as they want. If your application prevents them from doing the usual, they might begin to dislike your application. Users feel comfortable when an application follows de facto standards.

   Nevertheless, you can make the check boxes act like option buttons, but you will have to put code in the check boxes' Click() event procedures to remove the check from the current check box when the user clicks another check box. The code is fairly trivial, but again, your users will adapt more easily to your application if you use option buttons in mutually exclusive cases.

2. How can I trust the Timer control if it isn't accurate?

   The Timer control is accurate, but your computer cannot always let Windows respond to events exactly when needed. A multitasking operating system such as Windows does a lot of things at once. If a Timer() event occurs, the operating system cannot always, at that exact millisecond, go back to the running application and signal that the event occurred. Therefore, your applications sometimes take a back seat to system operations. Today's fast computers have much less of a time-accuracy problem than in the past, so you shouldn't worry too much about the potential millisecond miss now and then.

Share This