Special Edition Using Visual Basic 6

877 Pages·1998·10.09 MB·English

by  Brian Siler

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Brian Siler and Jeff Spotts
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iv Special Edition Using Visual Basic 6
Special Edition Using Visual Basic® 6
Copyright© 1998 by Que
All rights reserved. No part of this book shall be reproduced, stored
in a retrieval system, or transmitted by any means, electronic, me-
chanical, photocopying, recording, or otherwise, without written
permission from the publisher. No patent liability is assumed with
respect to the use of the information contained herein. Although
every precaution has been taken in the preparation of this book, the
publisher and author assume no responsibility for errors or omis-
sions. Neither is any liability assumed for damages resulting from
the use of the information contained herein.
International Standard Book Number: 0-7897-1542-2
Library of Congress Catalog Card Number: 98-84617
Printed in the United States of America
First Printing: September 1998
00 99 98 4 3 2 1
Trademarks
All terms mentioned in this book that are known to be trademarks
or service marks have been appropriately capitalized. Que cannot
attest to the accuracy of this information. Use of a term in this book
should not be regarded as affecting the validity of any trademark or
service mark.
Windows is a registered trademark of Microsoft Corporation.
Visual Basic is a registered trademark of Microsoft Corporation.
Warning and Disclaimer
Every effort has been made to make this book as complete and as
accurate as possible, but no warranty or fitness is implied. The
information provided is on an “as is” basis. The authors and the
publisher shall have neither liability or responsibility to any person
or entity with respect to any loss or damages arising from the infor-
mation contained in this book.
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Contents v
Contents at a Glance
I Getting Started with Visual Basic
1 Starting Out with Visual Basic 11
2 Creating Your First Program 17
3 Visual Basic Building Blocks 39
4 Using Visual Basic’s Default Controls 59
II Programming with Visual Basic
5 Responding to the User with Event Procedures 95
6 Giving More Control to the User: Menus and Toolbars 107
7 Using Dialog Boxes to Get Information 139
8 Using Variables to Store Information 159
9 Visual Basic Programming Fundamentals 173
10 Controlling the Flow of Your Program Code 203
11 Managing Your Project: Sub Procedures, Functions, and Multiple Forms 223
III Visual Basic Program Components
12 Microsoft Common Controls 245
13 Working with Control Arrays 289
14 Creating ActiveX Controls 305
15 Extending ActiveX Controls 341
16 Classes: Resusable Components 359
IV Visual Basic Interfaces
17 Multiple Document Interface Applications 381
18 Proper Interface Design 409
19 Using Visual Design Elements 425
V Advanced Programming Topics
20 Accessing the Windows API 449
21 Working with Files 469
22 Using OLE to Control Other Applications 489
23 Master’s Toolbox 501
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vi Special Edition Using Visual Basic 6
VI Visual Basic and Databases
24 Database Basics 527
25 The Data Control and Data-Bound Controls 545
26 Using Data Access Objects (DAO) 565
27 Using Remote Data Objects (RDO) 595
28 Using ActiveX Data Objects (ADO) 611
29 Creating Reports 641
VII Visual Basic and the Internet
30 Using VBScript 665
31 Active Server Pages 687
32 ActiveX Documents 719
33 Visual Basic and Other Uses of the Internet 741
VIII Appendixes
A Introduction to the Development Environment 759
B Packaging Your Applications 775
C SQL Summary 793
Index 829
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Contents vii
Table of Contents
Introduction 1
Getting Information From the User 23
Adding a TextBox Control 23
Fundamental Visual Basic Program-
Labeling Your Program’s Controls 28
ming 2
Adding a Command Button 29
Working with Visual Basic Components 3
Changing a Form’s Properties 30
Creating Application Interfaces 4 Saving Your Work—Again… 31
Advanced Visual Basic Programming 4 Coding Your Program’s Actions 31
Responding to Events 31
Database Programming Techniques 5
Specifying Event Procedures 33
Additional References 5 Writing Program Code 34
Source Code and Programs Used in This Running Your Program 36
Book 6
From Here… 38
Conventions and Special Elements Used in
This Book 6 3 Visual Basic Building Blocks 39
Forms 40
I Getting Started with Visual Parts of a Form 40
What Do Forms Do? 41
Basic 9
Using Controls 41
What Are Controls? 41
1 Starting Out with Visual Basic 11
Control Functions 42
What Is a Computer Program? 12 Exploring Properties 42
Property Basics 43
Computer Programs and Programming
Common Properties 44
Languages 13
Using Properties to Control an Object’s
Visual Basic Is a Smart Language 14 Size 44
Using Properties to Adjust an Object’s
The Importance of Designing Your
Position 44
Program 14
Changing Properties at Runtime 45
How Design Fits into the Programming
Using Properties to Control User Inter-
Process 15
action 48
Program Design in a Nutshell 15
Referencing Forms and Controls from
From Here… 16 Your Code 49
A First Look at Methods and Events 50
2 Creating Your First Program 17
Taking Action with Methods 50
Responding to Actions with Events 51
Creating Your Program’s User Inter-
How Properties and Methods Are Re-
face 18
lated 51
Getting Started 18
Saving Your Work 20 Form Properties Revisited 52
Displaying a Form 55
From Here… 57
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viii Special Edition Using Visual Basic 6
4 Using Visual Basic’s Default Calling an Event Procedure from
Controls 59 Code 101
Understanding Event Sequences 102
Introduction to the Intrinsic Controls 60
Multiple Events for Each Action 102
Working with Text 62 Determining the Order of Events 103
Displaying Text with a Label Con-
From Here… 106
trol 63
Entering Text with a Text Box 65
6 Giving More Control to the User:
Controls for Making Choices 66
Menus and Toolbars 107
The Command Button 67
Check Boxes 68 Creating a Menu Bar 108
Option Buttons 68 Common Menus 109
The List Box 70 Setting Up the Main Items 110
The Combo Box 75 Multiple-Level Menus 112
Grouping Menu Items 114
Special-Purpose Controls 78
Modifying the Menu 115
Scrollbars 78
Adding Access Keys and Shortcut Keys
The Timer Control 81
for Quick Access 116
Frames 83
Writing Code for the Menu Items 119
Working with Multiple Controls at Optional Settings 119
Designtime 85
Creating Pop-Up Menus 122
Selecting Multiple Controls 86
Creating the Menu to Be Dis-
Using the Properties Window 87
played 123
Using the Form Editor Toolbar 87
Activating a Pop-Up Menu 124
Using the Format Menu 89
Multiple Controls in a Frame 90 Using Toolbars in Visual Basic 124
Toolbar Basics 125
Working with the Controls Collection 90
Getting the Images for Your
Changing All Controls 90
Toolbar 126
Changing Selected Controls 91
Creating a Standard Toolbar 127
From Here… 91 Creating the Toolbar’s Buttons 129
Starting a Toolbar Example 131
Enabling the Buttons with Code 132
II Programming with Visual
Creating a Toolbar with Code 133
Basic 93 Allowing the User to Customize the
Toolbar 135
5 Responding to the User with Event Using the CoolBar Control 136
Procedures 95 From Here… 137
Introducing Events 96 7 Using Dialog Boxes to Get
Handling Events in Your Programs 97 Information 139
Determining When an Event Has Oc-
curred 97 Keeping the User Informed 140
Types of Events 98 Understanding the Message Box 140
Writing Event Procedures 100 Displaying a Message 141
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Contents ix
Returning a Value from the MsgBox What’s Different About Constants 171
Function 143 How to Use Constants 171
Demonstrating the MsgBox Func- Constants That Visual Basic Sup-
tion 146 plies 171
Creating Your Own Constants 172
Getting Information from the User 146
Setting Up the InputBox Function 146 From Here… 172
Values Returned by InputBox 147
9 Visual Basic Programming
Using Built-In Dialog Boxes 148
Fundamentals 173
General Usage of the CommonDialog
Control 148
Writing Statements 174
Testing the CommonDialog Con-
trol 149 Using Assignment Statements 175
The File Dialog Boxes 150
Using Math Operations 176
The Font Dialog Box 152
Addition and Subtraction 177
The Color Dialog Box 154
Multiplication and Division 178
The Print Dialog Box 155
Exponentiation 181
The Help Dialog Box 157
Operator Precedence 181
Creating Your Own Dialog Boxes 157
Working with Strings 182
Creating a Custom Dialog Box 157
String Concatenation 183
Using Form Templates for Other Dialog
Determining the Length of the
Boxes 157
String 185
From Here… 158 Changing the Case of a String 185
Searching a String 187
8 Using Variables and Constants to Extracting Pieces of a String 189
Store Information 159 Getting Rid of Spaces 191
Replacing Characters in a String 191
Introduction to Variables 160 Working with Specific Characters 193
Naming Variables 160 Strings and Numbers 194
Types of Variables 161
Formatting Results 195
Variable Declarations 163 Specific Formatting Functions 195
Explicit Declaration 163 Using the Format Function 197
Implicit Declaration 164 Manipulating Date Values 200
Fixed-Length Strings 165
From Here… 202
Variable Arrays 166
10 Controlling the Flow of Your Program
Determining Where a Variable Can Be
Code 203
Used 166
Creating Variables That Are Available
Making Decisions in Your Program 204
Everywhere 167
Using the If Statement 204
Keeping a Variable Local 168
Working with the False Condition 205
Using Static Variables 168
Working with Multiple If State-
Using the Option Explicit Statement 169 ments 206
Using Select Case 207
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Working with Loops 209 III Visual Basic Program
For Loops 210
Components 243
Do Loops 211
Enumeration Loops 214
12 Microsoft Common Controls 245
Debugging Your Programs 214
Stepping Through Your Code 216 Introduction to the Common Controls 246
Working in the Immediate Win-
dow 217 The ImageList: A Fundamental Common
Tracking Variable Values 218 Control 248
Setting Up an ImageList at
Error Trapping 219 Designtime 248
Using the On Error Statement 219 Setting Up an ImageList with
Labeling Code Lines 219 Code 249
Controlling Program Flow After
an Error 220 Organizing Your Data 250
Determining the Type of Error 221 Using the ListView Control 251
Using the TreeView Control 258
From Here… 222 Using the TabStrip Control 261
11 Managing Your Project: Sub Accepting User Input 266
Using an ImageCombo Control 266
Procedures, Functions, and Multiple
The UpDown Control 269
Forms 223
Working with Dates 271
Sliding into Numbers 275
Using Procedures and Functions 224
Working with Procedures 224 Reporting Status and Progress 278
Working with Functions 231 Adding a Status Bar to Your Pro-
Determining the Scope of Procedures gram 279
and Functions 232 Progress Bar 284
Reusing Functions and Proce- Adding Video with the Animation Con-
dures 233 trol 285
Working with Multiple Forms 235 From Here… 287
Adding New Forms to Your Pro-
gram 235 13 Working with Control Arrays 289
Adding Code Modules to a Project 236
Accessing the Forms and Modules of a Introducing Control Arrays 290
Project 236 Control Array Elements 290
Understanding the Advantages of Con-
Managing Components in Your
trol Arrays 290
Project 237
Managing Program References 238 Creating a Control Array 291
Controlling Your Controls 238 Adding Control Arrays to a Form 291
Adding Forms, Modules, and Classes Writing Code for a Control Array 294
to the Project 238 Removing Elements from a Control Ar-
Removing Pieces 241 ray 296
Controlling How Your Program Starts 241 Working with Control Arrays 296
Setting the Startup Form 241 Using a Control Array in Your Pro-
Using Sub Main 241 grams 296
From Here… 242
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