Professional Design Patterns in VB.NET: Building Adaptable Applications

365 Pages·2002·19.89 MB·English

by  Tom Fischer

Summary of Contents
Introduction
Chapter 1: Introduction to Design Patterns
Chapter 2: Design Patterns in the Data Tier
Chapter 3: Design Patterns in the Middle Tier
Chapter 4: Design Patterns in the Presentation Tier
Chapter 5: Between the Tiers: Design Patterns and .NET Remoting
Chapter 6: What Next?
Appendix A: UML Primer
Index
Professional
Design Patterns in VB.NET:
Building Adaptable Applications
Tom Fischer
John Slater
Pete Stromquist
ChaurG. Wu
APress Media, LLC
Professional
Design Patterns in VB.NET:
Building Adaptable Applications
© 2002 by Apress
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
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ISBN 978-1-59059-274-8 ISBN 978-1-4302-0783-2 (eBook)
DOI 10.1007/978-1-4302-0783-2
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About the Authors
Tom Fischer
Tom Fischer's career spans a broad range of technologies, working with some of the most
prestigious consulting firms in the Twin Cities. His certifications include the Sun Certified Java
Programmer (SejP), Microsoft Certified Solution Developer (MCSD), and Microsoft Certified
Database Administrator (MCDBA).
As a Microsoft Certified Teacher (MCT), Tom also helps teach other developers about the latest
.NET tools and technologies.
I would like to dedicate my contributions to Theresa, Ali, and Kate. They are the greatest! - TF
John Slater
John Slater is a project manager at Management Reports International in Cleveland, OH. At
MRI he is currently developing applications for the property management industry. Right now,
he is working on several projects using .NET development tools and .NET Enterprise servers.
In his free time John enjoys outdoor activities and playing with his children Rachel and Nathan.
He can be reached [email protected].
Pete StromquIst
Pete Stromquist is a consultant at Microsoft Technologies (one of the nation's premier Microsoft
Certified Solution ProViders), specializing in web-enabled application development using
Microsoft tools and technologies. He has spent the last several years architecting and developing
the following types of applications: intranet content management, web-enabled training and
testing software, B2B and B2C e-commerce, and web-based telemetry and logistics. He has
complemented his VB skills with several other technologies such as: XML, XSL, COM+, lIS,
ASP, and of course .NET.
Pete also enjoys teaching and presenting on .NET technologies. He has a Mechanical
Engineering background, and received his Bachelor of Science from the University of Minnesota.
ChaurG. Wu
Chaur Wu currently works for Trend Micro Inc. as a senior software engineer. He started
software programming before he was old enough to qualify for a driving license. The first
program he wrote was a bingo game - in assembly code on an 8051 Single chip. To capitalize on
the program, he ran a small casino in the lab - he developed primitive game boxes that
connected his pals and allowed them to place bets.
He's also been involved in much larger projects. For example, he developed a program in C++
to simulate the movement and geographical coverage of GPS satellites. As a research assistant in
his graduate study, he implemented a wavelet-based video compression algorithm for a traffic
surveillance system sponsored by Boston City Department of Transportation. He also helped
solve a blurred image problem using inverse filters and other image processing algorithms for a
client who designs fiber optics components in San Jose, CA.
His technical interests include distributed software systems inJava, COM, and .NET, generative
programming, software deSign, and neural networks. Outside of work, his favorite vacation combines
a one-night gambling trip to Reno followed by a day of skiing at some resort near Lake Tahoe.
You can email [email protected].
I would like to dedicate my efforts in this book to my two-year-old daughter, Sarah.
-CGW
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Table of Contents
Introduction 1
Who Is This Book For? 2
What Does This Book Cover? 2
What This Book Does Not Cover 3
What You Need to Use This Book 3
Style Conventions 4
Customer Support and Feedback 5
Source Code and Updates 5
Errata 6
forums.apress.com 6
Chapter 1: Introduction to Desl@ Patterns 9
What Is a Design Pattem? 10
Catalogs of Patterns 10
The Gang of Four 10
Other Catalogs and Resources 11
Design Patterns and Visual Basic 11
The Arrival of VB. NET 12
When Should we use Design Patterns? 12
How a Design Pattern can Improve a Design 13
The Actional TakeHomePay Application 13
The Building Blocks 16
Creational Patterns 17
The Singleton Design Pattem 18
The Abstract Factory Design Pattem 21
The Factory Method Design Pattem 26
Structural Patterns 29
The Adapter and Fagade Design Pattems 29
The Bridge Design Pattem 34
The Composite Design Pattem 39
The Decorator Design Pattem 43
The Proxy Design Pattem 49
Behavioral Patterns 51
The Observer Design Pattem 52
The State Design Pattem 55
The Strategy and Template Method Design Patterns 60
Table of Contents
Application of Design Patterns 64
Pattern Selection 64
Summary 66
Chapter 2: Design Patterns in the Data Tier 69
Requirements of a Data Tier 70
A Requirements List 71
Analysing the Requirements 71
Data-Tier Architecture 72
A Simple but Inflexible Data-Tier Example 72
A Slightly More Maintainable Example 74
Creating a Flexible Data Access Framework 75
The . NE T Data Providers 75
The .NET Data Provider Objects 76
The Design Patterns Analysis 77
Building the Data Tier 82
A UML Class Diagram 83
Building the Output Classes 84
The Abstract Base Output Classes 84
The Concrete Product Classes 85
Building the Factory Classes 88
The Abstract Factory Class 88
The NWDSARequest Helper Class 89
Managing Connection Strings 92
The Concrete Factory Classes 95
Compiling the Data Tier Application 103
Testing the Data Tier Application 104
A Simple Windows Test Application 104
Building the Application 104
Testing the SQL Server .NET Data Provider 109
Testing the OLE DB .NET Data Provider 109
Testing the ODBC .NET Data Provider 110
A Simple Web Test Application 111
Summary 114
Chapter 3: Design Patterns In the Middle Tier 117
Handling Orders 118
Business Requirements 118
Technology Requirements 119
Analysis and Design 119
Use Case Diagrams 120
Activity Diagrams 121
Homing in on Patterns 122
Sequence Diagrams 124
Class Diagrams 125
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