Karl Moore's Visual Basic .NET:

The Tutorials KARL MOORE

APress Media, LLC

Karl Moore's Visual Basic .NET: The Tutorials Copyright © 2002 by Karl Moore Originally published by Apress in 2002

All rights reserved. No part of this work may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval system, without the prior written permission of the copyright owner and the publisher.

ISBN 978-1-59059-021-8 ISBN 978-1-4302-1153-2 (eBook) DOI 10.1007/978-1-4302-1153-2

Trademarked names may appear in this book. Rather than use a trademark symbol with every occurrence of a trademarked name, we use the names only in an editorial fashion and to the benefit of the trademark owner, with no intention of infringement of the trademark.

Technical Reviewers: Patricia Moore, Richard Costall, Ray Ellison, Erik Giggey, Donald Carter Editorial Directors: Steve Anglin, Dan Appleman, Ewan Buckingham, Gary Cornell, Tony Davis,

Iason Gilmore, Dominic Shakeshaft, Iim Sumser, Karen Watterson, Iohn Zukowski Managing Editor: Grace Wong Project Manager: Alexa Stuart Copy Editor: Tom Gillen Production Editors: IanetVail and Grace Wong Compositor: Impressions Book and Iournal Services, Inc. Indexer: Ann Rogers Cover Designer: Tom Debolski Marketing Manager: Stephanie Rodriguez

The information in this book is distributed on an "as is" hasis, without warranty. Although every precaution has been taken in the preparation of this work, neither the author nor Apress shall have any liability to any person or entity with respect to any loss or damage caused or alleged to be caused directly or indirectly by the information contained in this work.

Dedicated to my loving family: David, Patricia, and]o-Anne.

Oh, and my brain-without whom none of this would've been possible.

Brief Contents

Foreword ............................................................. . xiii

About the Author .................................................... . xv

About This Book .................................................... . xvii

Tutorial 1: Beginning VB . NET ................................ . I

1.1 Programming, Visual Basic, and Everything .................. . 3

1. 2 Exploring Controls and Making Decisions ................... .23

1. 3 Variables and the Coolest Code .............................. . 51

1. 4 Menus, Methods, Modules, and Multiple Forms ............... 71

1. 5 Errors, Setup, and Going from Here ......................... . 95

Tutorial 2: Doing Databases ................................ . 117

2.1 Introducing Databases ....................................... . 119

2. 2 Our Own Database and VB . NET ............................... . 137

2. 3 Doing It Completely in Code ................................ . 165

2.4 SQL Server, Web Applications, Transactions ••• Oh My! ..... 189

2. 5 Designing Reports and Going from Here .................... . 219

Tutorial 3: Working the Web ................................ . 241

3.1 The ASP. NET Revolution ...................................... . 243

3.2 Ten Top Code Snippets You Can't Live Without ............ . 277

3. 3 Authentication, Tips, Distribution, and More ............ . 293

v

Brief Contents

Tutorial 4: Going Mobile ..................................... . 319

4.1 Introducing the Mobile Internet Toolkit .................. . 321

4.2 Your Device, Filters, Images, Memory, and More .......... . 343

Tutorial 5: Using Objects .................................. .. 367

5.1 Why Objects Are Important .................................. .. 369

5.2 Objects in Real Life, Class Libraries, and More ........ .. 391

Tutorial 6: Services Rendered .............................. .417

6.1 Introducing the World of Web Services .................... .419

Tutorial 7: From VB6 to . NET ............................... .445

7.1 All the Changes, Quickly .................................... .447

Tutorial 8: Tips and Techinques ........................... .475

8.1 Beginner Tips and Techniques ............................... .477

8. 2 Intermediate Tips and Techniques .......................... .487

8.3 Advanced Tips and Techniques .............................. .. 505

Appendixes ........................................................ . 531

Appendix A Installing Visual Studio • NET ...................... . 533

Appendix B Project Defaults .................................... .. 536

Appendix C Standard Naming Conventions ........................ . 542

Appendix D Windows Form Controls .............................. .. 545

Appendix E VB • NET Data Types .................................. .. 548

Appendix F SQL Server Data Types .............................. .. 550

Index ................................................................ . 553

vi

Contents

Foreword ............................................................. . xiii

About the Author .................................................... . xv

About This Book .................................................... . xvii

Tutorial 1 Beginning VB . NET ........................ . 1

1.1 Programming, Visual Basic, and Everything ..... . 3

What Is VB . NET? .................................................... .4

Creating Your First Program ....................................... . 5

Conclusion .......................................................... . 19 Review Sheet ........................................................ . 21

1. 2 Exploring Controls and Making Decisions ....... .23

Exploring Controls ................................................. .23 Responding to Events .............................................. . 27

The Top Ten Controls .............................................. .29 Bringing It All Together .......................................... . 38

Making Decisions ................................................... .44 Conclusion .......................................................... . 46

Review Sheet ........................................................ . 49

1. 3 Variables and the Coolest Code ................... .. 51

Using Variables .................................................... . 51

Time for a Test .................................................... . 56 And Now, the Cool Stuff! .......................................... . 57 Conclusion .......................................................... . 67

Review Sheet ........................................................ . 69

vii

Contents

1.4 Menus, Methods, Modules, and Multiple Forms ............................................ . 71

Expanding with Menus .............................................. . 71

Expanding with Forms ............................................... 77 Expanding with Methods ............................................ . 81

Expanding with Functions .......................................... . 83

Methods, Modules, Mayhem-oh My! ................................. . 89

Conclusion .......................................................... . 92

Review Sheet ........................................................ . 93

1. 5 Errors, Setup, and Going from Here .............. . 95

Handling the Errors ............................................... . 95

Distributing Your Program ....................................... . 100

FAQ ................................................................. . 108

Where to Go from Here ............................................ . 111

Conclusion ......................................................... . 113

Review Sheet ....................................................... . 115

Tutorial 2 Doing Databases ........................ .. 117

2.1 Introducing Databases ................................ . 119

What Are Databases? .............................................. . 120

Choices, Choices .................................................. . 122

Exploring Northwind .............................................. . 122

Doing the Data Bind .............................................. . 126

Conclusion ......................................................... . 134

Review Sheet ........................................................ . 136

2. 2 Our Own Database and VB . NET ...................... . 137

Creating Our Own Database ....................................... . 137 Adding Relationships ............................................. . 141

Binding to a Windows Form ....................................... . 145

Binding on the Web ................................................ . 154

Using the Wizards ................................................. . 159

Conclusion ......................................................... . 161

Review Sheet ........................................................ . 163

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Contents

2. 3 Doing It Completely in Code ........................ . 165

Talking the Talk .................................................. . 165

Cheating at SQL ................................................... . 170

Accessing in Code ................................................. . 171

Our Completely-in-Code Program ................................. . 172

Expanding with Relationships .................................... . 181

Conclusion ......................................................... . 186

Review Sheet ........................................................ . 187

2.4 SQL Server, Web Applications, Transactions . .. Oh My! ...................................... . 189

Joining the Big Boys ............................................. . 189

Creating a Server Database ...................................... . 191

Creating a Transactional Database-Powered Web Application ............................................... . 200

And for My Next Trick ... Transactions! ......................... .210

Conclusion ......................................................... . 215

Review Sheet ........................................................ . 217

2. 5 Designing Reports and Going from Here ......... . 219

Reporting with Crystal ........................................... . 219

FAQ ................................................................. . 232 Where to Go from Here ............................................ .236

Conclusion ......................................................... . 237

Review Sheet ........................................................ . 139

Tutorial 3 Working the Web ......................... . 241

3 .1 The ASP. NET Revolution ............................... . 243

How It All Works .................................................. .244

Creating Your First Site ........................................ . 244

Getting Bigger and Better ....................................... .248

The Greatest Controls Ever Sold ................................ . 258

Conclusion ......................................................... . 272

Review Sheet ........................................................ . 273

ix

Contents

3.2 Ten Top Code Snippets You Can't Live Without ................................................... . 277

The Top Ten List .................................................. . 277 Quiz Time .......................................................... . 288

Conclusion ......................................................... . 290

Review Sheet ........................................................ . 291

3.3 Authentication, Tips, Distribution, and More ..................................... .293

Securing Your Sites .............................................. .293

Improving Your Site .............................................. . 303

Deployment ......................................................... . 309

FAQ ................................................................. . 311

Conclusion ......................................................... . 315

Review Sheet ........................................................ . 317

Tutorial 4 Going Mobile .............................. . 319

4.1 Introducing the Mobile Internet Toolkit ...... . 321

How Does It Work? ................................................. . 322 Creating Our First Mobile Application ......................... . 323

Exploring the Controls ........................................... . 330

I'm Playing Around ................................................ . 339

Conclusion ......................................................... . 340

Review Sheet ........................................................ . 341

4.2 Your Device, Filters, Images, Memory, and More ............................................. . 343

Finding Out about Your Device ................................... . 343

A Word about Filters ............................................. . 348

Displaying Images, Using Filters ............................... . 354

Do You Remember? .................................................. . 358

FAQ ................................................................. . 360

Conclusion ......................................................... . 363

Review Sheet ........................................................ . 365

X

Contents

Tutorial 5 Using Objects ........................... .. 367

5.1 Why Objects Are Important .......................... . 369

What Are Objects? ................................................. . 369

Starting Small .................................................... . 372 Adding Properties ................................................. . 376

Bettering Properties ............................................. . 378

Methods, Functions, Parameters-Oh My! ......................... . 382

Events .............................................................. . 383 Going Further ...................................................... . 386

Conclusion ......................................................... . 387

Review Sheet ........................................................ . 389

5.2 Objects in Real Life, Class Libraries, and More ......................................................... . 391

Creating a Customers Class ...................................... . 391

Adding a Test Project ............................................ . 397

Time for a Chat ................................................... . 401

Distributing Your DLL ............................................ .404

FAQ ................................................................. .405 Conclusion ......................................................... . 412

Review Sheet ........................................................ . 413

Tutorial 6 Services Rendered ..................... .417

6.1 Introducing the World of Web Services ......... .419

How It All Works .................................................. .419

Creating a Web Service ........................................... . 422

Imagining the Possibilities ..................................... . 429

Passing Smart Data ................................................ .430

The Top Five Distribution Tips ................................. .435

Deploying Your Web Service ...................................... .437

FAQ ................................................................. . 438

Where to Go from Here ............................................ .440 Conclusion ......................................................... . 441

Review Sheet ........................................................ . 443

xi

Contents

Tutorial 1 From VB6 to . NET ....................... .445

7.1 All The Changes, Quickly ............................ .447

What is • NET? ...................................................... . 447

Introducing Visual Studio . NET ................................. .450

How Your Code Changes ............................................ .456

They're Objects, Jim ••........................................... .462

Getting It Out .................................................... . 471

Upgrading Your Existing Applications .......................... .472

Where to Go from Here ............................................ .472

Conclusion ......................................................... . 474

Tutorial 8 Tips and Techniques .................. .475

8.1 Beginner Tips and Techniques ...................... .477

Making Your Form Transparent .................................... .478

Snapping to the Grid ............................................. .478

Resizing Controls at Runtime .................................... .478

Adding Menus to Your Program .................................... .479

Changing Your Window State ...................................... .479

Adding the With Keyword .......................................... .479

Using Visual Inheritance ........................................ .480

Typing the TODO: Statement ...................................... .480

Setting a Site Home page .......................................... .480

Adding Smart Navigation to Web Forms .......................... .481

Changing the Tab Order .......................................... .. 481

Generating Random Numbers ........................................ .481

Exiting Your Code ................................................. .482

Customizing the Cursor ........................................... .482

Using Special Code Characters ................................... .482

Creating a Number-Only Text Box ................................ .483

Reversing a String ................................................ .484

Rounding a Number ................................................. .484

Replacing Text the Easy Way .................................... .. 484

Listing and Setting Fonts ....................................... .485

Trimming a String ................................................. .485

Ending Your Application .......................................... .486

Retrieving a Number Using Val ................................... .486

Resetting the Windows ............................................ .486

Capitalizing Your Characters .................................... .486

xii

8. 2 Intermediate Tips and Techniques ................ .487

Finding the Application Directory .............................. .488

Formatting Dates .................................................. .488

Exploring the Command Window .................................... .490

Creating an MDI Application ..................................... .490

Adding Toolbars ................................................... .491

Reading an XML File .............................................. .492

Using DataSets and XML ........................................... .494

Creating Your Own Icons .......................................... .495

Reading and Writing to Files .................................... .495

Finding the Last Day of the Month .............................. .496

Using the Handles Keyword ....................................... .497

Converting Text to Proper Case ................................. .498

Storing to the Clipboard ........................................ .498

Working with Files ................................................ .498

Highlighting Form Errors ........................................ .499

Using the IIF Function ........................................... . 500

Validating an Email Address ..................................... . 500

Resetting a Form .................................................. . 503

8. 3 Advanced Tips and Techniques ...................... . 505

Introducing the VS. NET Command Prompt ......................... . 506

Using Keywords in Your Code ..................................... . 506

Declaring Static Variables ...................................... . 507

Checking for a Leap Year ........................................ . 507

Creating a GUID ................................................... . 507

Generating OLE DB Strings with Ease ........................... . 508

Checking for a Whole Number .................................... .. 509

Read the Command Line Parameters ............................... . 509

Getting Special Folder Locations ............................... . 510

Checking for a Previous Instance ............................... . 510

Saving to the Registry ........................................... . 511

Using COM Objects ................................................. . 512

Turning a Recordset into a DataSet ............................ .. 513

Exposing .NET to the COM World ................................ .. 513

Storing Often-Used Code .......................................... . 514

Saving Time with Macros ......................................... .. 514

Using Simple Encryption .......................................... . 514

Encrypting a File ................................................. . 516

Generating Memorable Passwords ................................. . 519

Printing from Your Program ...................................... . 520

xiii

Contents

Creating and Sorting Arrays ..................................... . 523

Using the Special Array Functions .............................. . 526

Collections in • NET .............................................. . 527

Finding MTS and MSMQ ............................................. . 528

Fine-Tuning Your ASP. NET Applications ......................... . 529

Appendixes .................................................... . 531

Appendix A Installing Visual Studio • NET .......... . 533

Appendix B Project Defaults ............................ .. 536

Appendix C Standard Naming Conventions ............. . 542

Appendix D Windows Form Controls ...................... . 545

Appendix E VB • NET Data Types .......................... . 548

Appendix F SQL Server Data Types ...................... . 550

Index ............................................................... . 553

xiv

Foreword

"The man who has no imagination has no wings."-MuhammadAli

NOT EVERYTHING IN LIFE IS EASY.

Nuclear physics. Advanced trigonometry. The Welsh language. Pushing a twenty-ton truck up a hill using your left pinkie. That's not easy.

But some things definitely are. Like programming, say. The problem is, if you've ever tried to learn how to program, you'll know most

of the books out there are about as exciting as Bill Gates' cardigan collection. They're full of annoying acronyms and confusing concepts. On every other page, they stick whopping great big tables containing "keywords to remember."

Yeah, like that's going to happen. When I decided to teach programming online some years ago, I decided to go

against the flow. I decided to use what I knew about the learning process to help my readers understand concepts quicker and to actually enjoy the whole process.

I wrote in plain English. I constantly linked new concepts back to stuff each reader already knew. I presented the big picture and kept asking questions. I reg­ularly presented review sheets. I explained geek speak. I held the users' hands at first, pointed out potential pitfalls, then let each individual fly.

It worked, and the response blew me away. Thankfully, I managed to catch a plane back-and began writing the book

you're holding right now, all about the new .NET technologies. And this baby

works in just the same way as my online tutorials, only better. My mum is so proud. This book is split into eight separate tutorials, each of which teaches a real­

to-life area of programming. From databases to the Web, it's all here, and each tutorial will turn you into a real guru, with suggestions as to how you can take your knowledge even further.

So, let's prepare to enter the nerd world. Grow a beard and apply a little EO­and remember, don't worry and don't memorize. Just play and have fun!

Thank you for learning with me. Karl Moore, Apri/2002

XV

About the Author

KARL MooRE Is A TECHNOLOGY AUTHOR living in Yorkshire, England. He runs his own consultancy group, White Cliff Computing Ltd., and is senior editor behind the popular development site, VB-World. When he's not writing for magazines, speaking at conferences, or making embarrassing mistakes on live radio, Karl enjoys a complete lack of a social life.

Karl says his life goals include climbing out of bed, reaching the high notes in "Loving You", and learning to speak in hieroglyphics.

You can visit Karl on the Web at www. kar lmoore. com or email him at karl@karlmoore.com.

xvii

Acknowledgments

When I first plotted this book on a train home from Cardiff Central last year, I had­n't planned on including an Acknowledgments section. In fact, I'd only planned on three individual tutorials, one that never made it, and six extra that did.

But Acknowledgments? Hah, it was just me and my trusty fake-leather organizer. How very wrong I was. I've learned in the past months that writing a book is

a true culmination of efforts-and to all the people who have helped, I'd like to extend my sincere thanks.

First and foremost, thanks go to Tricia Moore, a family member and technical reviewer, for her patience and coordination skills-and for being one of the few people who didn't mind knocking me off my horse when things didn't work. Big appreciation also goes to project manager Alexa Stuart, who always managed to get me back on it.

Thanks to Tom Gillen, my editor, for recognizing that most of my best jokes were libelous and removing them before the lawyers did. Kudos to you, intelli­gent man. Also, my appreciation goes out to Grace Wong, who encountered all those last-minute typesetting hurdles-and survived. Plus I raise my hat to the best marketing queen of all, Stephanie Rodriguez.

Of course, the Apress editorial directors also need mentioning, not as a mat­ter of course, but because they're real people. First and foremost, Dan Appleman, who kept me entertained with readers' stories in London and has since regretted ever giving me his e-mail address; Gary Cornell, whom I shared an ice cream with in Barcelona and who convinced me that VB6 books were a dying breed back in the year 2000; and Karen Watterson, who provided much-needed moral support and now has her electricity back.

A big thanks also goes out to Mark and Katrina, the BBC pals who constantly remind me sleep is actually good for you. Also, the team behind my own com­pany, White Cliff, deserves a round of applause for their initiative and bright thinking-they're the people who continued to earn me a salary during the months I couldn't.

And, of course, the people who actually inspired the book: those who read my online scribblings and prompted me to go one step further. From the African King with an interest in programming, to the recently released Australian convict taking a long overdue career move, to Jenny in Auckland who has just passed her programming class with flying colors-you are the people who kept me burning the candle well into the midnight hours. Thank you.

Finally, to the most important people of all: Mum, Dad, and Jo-Anne. It is to these three I owe my life.

xix

About This Book

THIS BOOK IS SPLIT INTO EIGHT SEPARATE TUTORIALS, each designed tO get you Up tO speed with a different area of the .NET world:

'futoriall, "Beginning VB .NET": Who puts the fun into programming fun­damentals? If you're new to VB .NET, this is your starting block. This five-chapter tutorial will provide you with a thorough grounding in pro­gramming with your soon-to-be favorite language. Covering everything from painting a form to error handling.

'futorial2, "Doing Databases": In the real world, databases are essential. This five-chapter tutorial is your ultimate survival guide, covering every­thing from creating your own simple Access database through to writing your own transactional SQL Server-powered transactional Web appli­cation. Corr blimey, miss us.

'futorial3, "Working the Web": No matter how little Internet experience you have, this three-chapter ASP. NET tutorial will show you how to create your own fully interactive, advanced Web sites in minutes. Covering every­thing from Web controls to user authentication.

'futorial4, "Going Mobile": Fancy writing applications that can run on anything from your cell phone to that wired microwave? Get your VB .NET code talking in the language of mobile devices, with the free Mobile Internet Toolkit and this two-chapter lifesaver. A real eye-opener.

'futorial5, "Using Objects": Create better, more-maintainable, bug-free applications, quicker, by using object -oriented programming techniques. This two-chapter tutorial gives you the full lowdown on how using classes can really improve both your code and salary.

'futorial6, "Services Rendered": It's DCOM on a longer wire, it's a groovy way of getting computers talking to each other, it's a cross-platform XML­based communication method. It's cool, it's Web Services, and this single-chapter tutorial shows you how to get your own up and running within half an hour.

'futorial7, "From VB6 to .NET": If you've just moved to the world of .NET from Visual Basic 6, you need to get your head around a few changes. This

xxi

About This Book

xxii

one-chapter overview provides a quick rundown of the differences, plus advice on where to go from here.

Tutorial8, "Tips and Techniques": Split into Beginner, Intermediate, and Advanced chapters, this part provides reams of ready-to-run solutions to some of the most common .NET programming tasks. Whether you want to print from your program or generate OLE DB strings with ease, this nifty collection is a complete must-read for all developers.

Appendixes: Installing Visual Studio .NET, Project Defaults, Standard Naming Conventions, Windows Form Controls, VB .NET Data Types, and SQL Server Data Types.

If you're new to programming, it's recommended that you start with Thtoriall, "Beginning VB .NET", and then read through each tutorial sequentially. Every chap­ter builds upon the knowledge you acquired in the last. Also, ensure that you read the Review Sheets at the end of each chapter to help solidify your knowledge base.

If you have programmed in a previous version ofVisual Basic, start with Tutorial 7, "From VB6 to .NET", which should give you a grasp of changes in the new programming platform. After this, read the Review Sheets at the end of each chapter in Thtoriall "Beginning VB .NET", to ensure that you really grasp the key concepts. Once you've gotten an overview of the differences, start selectively reading the tutorials that interest you. Each includes special references for those coming from VB6.

Users of all levels will find it enormously beneficial to spend time browsing all the code samples in the three chapters ofThtorial8, "Tips and Techniques". They demonstrate real code in action and should help you grasp many of the techniques shown throughout the book.

Good luck!