Visual Basic 6


Apply Now

CONTENT

1. Introduction to the Visual Basic Language and

Environment

Preview...................................................................................................................1-1

Course Objectives.................................................................................................1-1

What is Visual Basic?...........................................................................................1-2

Visual Basic 6.0 versus Other Versions of Visual Basic ..................................1-3

16 Bits versus 32 Bits...........................................................................................1-3

Structure of a Visual Basic Application...............................................................1-4

Steps in Developing Application .........................................................................1-4

Drawing the User Interface and Setting Properties...........................................1-5

Example 1-1: Stopwatch Application - Drawing Controls.................................1-9

Setting Properties of Objects at Design Time ................................................ 1-10

Setting Properties at Run Time......................................................................... 1-11

How Names Are Used in Object Events..........................................................1-11

Example 1-2: Stopwatch Application - Setting Properties ............................1-12

Variables .............................................................................................................1-14

Visual Basic Data Types...................................................................................1-14

Variable Declaration..........................................................................................1-14

Example 1-3: Stopwatch Application - Attaching Code................................. 1-18

Quick Primer on Saving Visual Basic Applications........................................ 1-20

Exercise 1: Calendar/Time Display..................................................................1-21

iv Learn Visual Basic 6.0

2. The Visual Basic Language

Review and Preview..............................................................................................2-1

A Brief History of Basic.........................................................................................2-1

Visual Basic Statements and Expressions ........................................................2-2

Visual Basic Operators.........................................................................................2-3

Visual Basic Functions .........................................................................................2-4

A Closer Look at the Rnd Function......................................................................2-5

Example 2-1: Savings Account............................................................................2-6

Visual Basic Symbolic Constants.....................................................................2-10

Defining Your Own Constants ...........................................................................2-10

Visual Basic Branching - If Statements............................................................2-11

Key Trapping....................................................................................................... 2-12

Example 2-2: Savings Account - Key Trapping .............................................. 2-14

Select Case - Another Way to Branch.............................................................2-16

The GoTo Statement..........................................................................................2-17

Visual Basic Looping......................................................................................... 2-17

Visual Basic Counting........................................................................................ 2-19

Example 2-3: Savings Account - Decisions ....................................................2-20

Exercise 2-1: Computing a Mean and Standard Deviation...........................2-23

Exercise 2-2: Flash Card Addition Problems ................................................. 2-28

3. Exploring the Visual Basic Toolbox

Review and Preview..............................................................................................3-1

The Message Box .................................................................................................3-1

Object Methods......................................................................................................3-3

The Form Object....................................................................................................3-4

Command Buttons.................................................................................................3-5

Label Boxes...........................................................................................................3-5

Text Boxes..............................................................................................................3-6

Example 3-1: Password Validation.....................................................................3-8

Check Boxes....................................................................................................... 3-11

Option Buttons ....................................................................................................3-11

Arrays...................................................................................................................3-12

Control Arrays .....................................................................................................3-13

Frames................................................................................................................ 3-14

Example 3-2: Pizza Order................................................................................. 3-15

List Boxes............................................................................................................3-20

Combo Boxes.....................................................................................................3-21

Example 3-3: Flight Planner.............................................................................. 3-23

Exercise 3: Customer Database Input Screen................................................ 3-27

Contents v

4. More Exploration of the Visual Basic Toolbox

Review and Preview..............................................................................................4-1

Display Layers.......................................................................................................4-1

Line Tool.................................................................................................................4-2

Shape Tool.............................................................................................................4-3

Horizontal and Vertical Scroll Bars......................................................................4-4

Example 4-1: Temperature Conversion..............................................................4-7

Picture Boxes...................................................................................................... 4-12

Image Boxes ....................................................................................................... 4-14

Quick Example: Picture and Image Boxes ...................................................... 4-14

Drive List Box...................................................................................................... 4-15

Directory List Box ............................................................................................... 4-15

File List Box........................................................................................................ 4-16

Synchronizing the Drive, Directory, and File List Boxes................................ 4-17

Example 4-2: Image Viewer.............................................................................. 4-18

Common Dialog Boxes .....................................................................................4-23

Open Common Dialog Box............................................................................... 4-24

Quick Example: The Open Dialog Box............................................................4-25

Save As Common Dialog Box..........................................................................4-27

Quick Example: The Save As Dialog Box....................................................... 4-28

Exercise 4: Student Database Input Screen...................................................4-29

5. Creating a Stand-Alone Visual Basic Application

Review and Preview..............................................................................................5-1

Designing an Application.....................................................................................5-1

Using General Sub Procedures in Applications ................................................5-2

Creating a Code Module ......................................................................................5-5

Using General Function Procedures in Applications.........................................5-5

Quick Example: Temperature Conversion..........................................................5-7

Quick Example: Image Viewer (Optional)...........................................................5-8

Adding Menus to an Application..........................................................................5-8

Example 5-1: Note Editor ..................................................................................5-12

Using Pop-Up Menus......................................................................................... 5-16

Assigning Icons to Forms..................................................................................5-17

Designing Your Own Icon with IconEdit............................................................5-17

Creating Visual Basic Executable Files ..........................................................5-19

Example 5-2: Note Editor - Building an Executable

and Attaching an Icon................................................................. 5-21

Using the Visual Basic Package & Deployment Wizard ............................... 5-22

Example 5-3: Note Editor - Creating a Distribution Disk............................... 5-25

Exercise 5: US Capitals Quiz............................................................................5-27

vi Learn Visual Basic 6.0

6. Error-Handling, Debugging and File Input/Output

Review and Preview..............................................................................................6-1

Error Types.............................................................................................................6-1

Run-Time Error Trapping and Handling ..............................................................6-2

General Error Handling Procedure......................................................................6-4

Example 6-1: Simple Error Trapping ..................................................................6-7

Debugging Visual Basic Programs.....................................................................6-9

Example 6-2: Debugging Example ..................................................................6-10

Using the Debugging Tools............................................................................... 6-11

Debugging Strategies........................................................................................ 6-16

Sequential Files..................................................................................................6-17

Sequential File Output (Variables) ...................................................................6-17

Quick Example: Writing Variables to Sequential Files ..................................6-19

Sequential File Input (Variables)....................................................................... 6-20

Quick Example: Reading Variables from Sequential Files ...........................6-21

Writing and Reading Text Using Sequential Files..........................................6-22

Random Access Files........................................................................................ 6-24

User-Defined Variables.....................................................................................6-25

Writing and Reading Random Access Files...................................................6-26

Using the Open and Save Common Dialog Boxes........................................ 6-29

Example 6-3: Note Editor - Reading and Saving Text Files..........................6-31

Exercise 6-1: Information Tracking ...................................................................6-35

Exercise 6-2: ‘Recent Files’ Menu Option....................................................... 6-41

7. Graphics Techniques with Visual Basic

Review and Preview..............................................................................................7-1

Graphics Methods .................................................................................................7-1

Using Colors ..........................................................................................................7-8

Mouse Events .....................................................................................................7-10

Example 7-1: Blackboard..................................................................................7-13

Drag and Drop Events ....................................................................................... 7-18

Example 7-2: Letter Disposal ...........................................................................7-20

Timer Tool and Delays ....................................................................................... 7-23

Animation Techniques ....................................................................................... 7-24

Quick Example: Simple Animation...................................................................7-25

Quick Example: Animation with the Timer Tool............................................... 7-26

Random Numbers (Revisited) and Games .....................................................7-28

Randomly Sorting N Integers.............................................................................7-29

Example 7-3: One-Buttoned Bandit..................................................................7-30

User-Defined Coordinates................................................................................ 7-35

Simple Function Plotting (Line Charts) ............................................................7-36

Simple Bar Charts.............................................................................................. 7-38

Contents vii

7. Graphics Techniques with Visual Basic (continued)

Example 7-4: Line Chart and Bar Chart Application...................................... 7-40

Exercise 7-1: Blackjack.....................................................................................7-43

Exercise 7-2: Information Tracking Plotting.....................................................7-54

8. Database Access and Management

Review and Preview..............................................................................................8-1

Database Structure and Terminology .................................................................8-1

ADO Data Control.................................................................................................8-6

Data Links..............................................................................................................8-8

Assigning Tables...................................................................................................8-9

Bound Data Tools............................................................................................... 8-10

Example 8-1: Accessing the Books Database............................................... 8-12

Creating a Virtual Table.....................................................................................8-14

Quick Example: Forming a Virtual Table......................................................... 8-14

Finding Specific Records..................................................................................8-16

Example 8-2: ‘Rolodex’ Searching of the Books Database..........................8-18

Data Manager.....................................................................................................8-21

Example 8-3: Phone Directory - Creating the Database............................... 8-22

Database Management.....................................................................................8-24

Example 8-4: Phone Directory - Managing the Database.............................8-26

Custom Data Aware Controls ...........................................................................8-31

Creating a Data Report .....................................................................................8-33

Example 8-5: Phone Directory - Building a Data Report............................... 8-34

Exercise 8: Home Inventory Database.............................................................8-39

9. Dynamic Link Libraries and the Windows API

Review and Preview..............................................................................................9-1

Dynamic Link Libraries (DLL)..............................................................................9-1

Accessing the Windows API With DLL...............................................................9-2

Timing with DLL Calls ...........................................................................................9-4

Quick Example 1: Using GetTickCount to Build a Stopwatch.........................9-5

Quick Example 2: Using GetTickCount to Implement a Delay........................9-6

Drawing Ellipses....................................................................................................9-7

Quick Example 3: Drawing Ellipses...................................................................9-7

Drawing Lines........................................................................................................9-8

Quick Example 4: Drawing Lines .......................................................................9-9

Drawing Polygons .............................................................................................. 9-10

Quick Example 5: Drawing Polygons .............................................................. 9-11

Sounds with DLL Calls - Other Beeps .............................................................9-14

Quick Example 6: Adding Beeps to Message Box Displays ....................... 9-15

viii Learn Visual Basic 6.0

9. Dynamic Link Libraries and the Windows API (continued)

More Elaborate Sounds.....................................................................................9-16

Quick Example 7: Playing WAV Files.............................................................9-16

Playing Sounds Quickly .....................................................................................9-17

Quick Example 8: Playing Sounds Quickly.....................................................9-18

Fun With Graphics.............................................................................................. 9-19

Quick Example 9: Bouncing Ball With Sound!............................................... 9-20

Flicker Free Animation ...................................................................................... 9-22

Quick Example 10: Flicker Free Animation....................................................9-23

Quick Example 11: Horizontally Scrolling Background ................................. 9-24

A Bit of Multimedia .............................................................................................9-26

Quick Example 12: Multimedia Sound and Video......................................... 9-26

Exercise 9: The Original Video Game - Pong!............................................... 9-27

10. Other Visual Basic Topics

Review and Preview...........................................................................................10-1

Custom Controls................................................................................................. 10-1

Masked Edit Control..........................................................................................10-3

Chart Control....................................................................................................... 10-4

Multimedia Control.............................................................................................10-6

Rich Textbox Control..........................................................................................10-8

Slider Control...................................................................................................... 10-9

Tabbed Dialog Control ....................................................................................10-12

UpDown Control...............................................................................................10-13

Toolbar Control.................................................................................................10-14

Using the Windows Clipboard ........................................................................10-17

Printing with Visual Basic ................................................................................10-18

Multiple Form Visual Basic Applications.......................................................10-21

Visual Basic Multiple Document Interface (MDI)...........................................10-25

Creating a Help File .........................................................................................10-29

Class Summary................................................................................................10-36

Exercise 10: The Ultimate Application...........................................................10-37

Appendix I: Visual Basic Symbolic Constants ................................... I-1

Appendix II: Common Dialog Box Constants..................................... II-1