Programming VB .NET: A Guide for Experienced Programmers

514 Pages·2001·4.01 MB·English

by  Gary Cornell

Programming VB.NET:
A Guide for Experienced
Programmers
GARY CORNELL AND JONATHAN MORRISON
Programming VB.NET: A Guide for Experienced Programmers
Copyright ©2002 by Gary Cornell
All rights reserved. No part of this work may be reproduced or transmitted in any form or by any
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ISBN (pbk): 1-893115-99-2
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Dedication
To the people at Apress: the best group of people I can ever imagine working with.
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Contents at a Glance
Dedication ..............................................................................................................iii
Contents ....................................................................................................................v
Acknowledgments .................................................................................................viii
About This Book......................................................................................................ix
Chapter 1 Introduction.....................................................................................1
Chapter 2 The VB .NET IDE: Visual Studio .NET ..............................11
Chapter 3 Expressions, Operators, and Control Flow ...................47
Chapter 4 Classes and Objects (with a Short Introduction
to Object-Oriented Programming) .......................................97
Chapter 5 Inheritance and Interfaces................................................. 177
Chapter 6 Event Handling and Delegates ...........................................237
Chapter 7 Error Handling the VB .NET Way:
Living with Exceptions .........................................................265
Chapter 8 Windows Forms, Drawing, and Printing ..........................279
Chapter 9 Input/Output ..............................................................................333
Chapter 10 Multithreading ..........................................................................379
Chapter 11 A Brief Introduction to Database Access
with VB .NET ..............................................................................423
Chapter 12 A Brief Overview of ASP .NET ...........................................443
Chapter 13 .NET Assemblies, Deployment, and COM Interop .........463
Index.........................................................................................................................479
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Contents
Dedication............................................................................................................iii
Acknowledgments............................................................................................ xiii
About This Book.............................................................................................. xv
Chapter 1 Introduction ........................................................................1
Visual Basic Then and Now ..............................................................................1
The Versions of Visual Basic ........................................................................2
The .NET Mentality Shift ................................................................................3
The Common Language Runtime ......................................................................4
Completely Object Oriented ...............................................................................5
Automatic Garbage Collection: Fewer Memory Leaks .....................................6
Structured Exception Handling .....................................................................6
True Multithreading ...........................................................................................6
Why You Will Need To Learn a Whole Lot of New Concepts
to Use VB .NET ...............................................................................................7
Should You Use C# and Not Bother with VB .NET? ................................9
Chapter 2 The VB .NET IDE: Visual Studio .NET ...........11
Getting Started ..................................................................................................12
Creating a New Solution ...................................................................................13
A Tour of the Main Windows in the IDE ..................................................17
The Editor ...........................................................................................................19
The Solution Explorer ........................................................................................24
Properties Window ............................................................................................25
References and the Reference Window ...........................................................26
Output Window and Command Window ........................................................27
Working with a Solution ................................................................................28
Adding Projects to a Solution ............................................................................33
Compiling ...............................................................................................................34
Multiple Compilations ......................................................................................36
Build Options .....................................................................................................38
Debug vs. Release Versions ...............................................................................39
Output Files ........................................................................................................40
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Contents
Debugging in VB .NET ........................................................................................40
New Debugger Features .....................................................................................41
Chapter 3 Expressions, Operators,
and Control Flow .............................................................47
Console Applications ........................................................................................48
Statements in VB .NET ......................................................................................51
Comments ..................................................................................................................52
Variables and Variable Assignments .........................................................52
Literals and Their Associated Data Types ............................................54
Non-Numeric Literals ........................................................................................58
Declaring Variables ..........................................................................................59
Conversion between Values of Different Types ...............................................61
Strings ....................................................................................................................64
String Functions .................................................................................................65
Formatting Data .................................................................................................68
Arithmetic Operators ........................................................................................69
Parentheses and Precedence .............................................................................72
Math Functions and Math Constants ...............................................................73
Constants ................................................................................................................75
Repeating Operations—Loops ...........................................................................75
Determinate Loops .............................................................................................75
Indeterminate Loops ..........................................................................................77
Conditionals—Making Decisions ....................................................................79
Scoping Changes ................................................................................................80
Short Circuiting ..................................................................................................81
Select Case ...........................................................................................................81
The GoTo ..................................................................................................................82
The Logical Operators on the Bit Level ................................................83
Arrays ......................................................................................................................84
The For-Each Construct ....................................................................................86
Arrays with More than One Dimension ............................................................87
Procedures: User-Defined Functions and Subs .....................................87
Functions ............................................................................................................88
Sub Procedures ...................................................................................................90
Using Arrays with Functions and Procedures ..................................................92
Procedures with a Variable or Optional Number of Arguments ....................93
Recursion ................................................................................................................94
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Contents
Chapter 4 Classes and Objects (with a Short
Introduction to Object-Oriented
Programming) ......................................................................97
Introduction to OOP .........................................................................................98
Classes As (Smart) User-Defined Types ...........................................................99
The Vocabulary of OOP ...................................................................................101
The Relationships between Classes in Your Programs .................................101
How to Objectify Your Programs ...............................................................107
What about Individual Objects? ...............................................................109
Advantages to OOP ............................................................................................110
Creating Object Instances in VB .NET ..................................................111
More on Constructors: Parameterized Constructors ...................................114
Example: The String Class ..............................................................................115
Example: The StringBuilder Class ..................................................................115
Namespaces ...........................................................................................................120
Imports .............................................................................................................120
Help and the (Vast) .NET Framework ......................................................124
Example: The Framework Collection Classes ...............................................127
More on Object Variables ............................................................................134
Is and Nothing ..................................................................................................136
TypeName and TypeOf .........................................................................................137
Subtleties of Passing Object Variables by Value ............................................138
Building Your Own Classes ..........................................................................140
Overloading Class Members ...........................................................................144
More on Constructors .....................................................................................147
More on Properties ..........................................................................................148
Scope of Variables ............................................................................................150
Nested Classes ..................................................................................................152
Shared Data and Shared Members Inside Classes ..............................155
Shared Members ..............................................................................................157
The Object Life Cycle ...................................................................................158
Object Death ....................................................................................................160
Value Types .........................................................................................................161
Enums ...............................................................................................................163
Structure Types ................................................................................................165
Namespaces for Classes You Create .........................................................168
The Class View Window ...................................................................................169
Debugging Object-Based Programs .............................................................170
Summary .................................................................................................................175
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Contents
Chapter 5 Inheritance and Interfaces .................................177
Inheritance Basics ..........................................................................................178
Getting Started with Inheritance .....................................................................180
Overriding Properties and Methods ...............................................................184
Abstract Base Classes .......................................................................................195
Object: The Ultimate Base Class ..............................................................201
The Most Useful Members of Object ..............................................................202
The Fragile Base Class Problem: Versioning ......................................209
Overview of Interfaces .................................................................................215
Mechanics of Implementing an Interface ......................................................217
When to Use Interfaces, When To Use Inheritance? .........................222
Important Interfaces in the .NET Framework ......................................222
ICloneable .........................................................................................................223
IDisposable .......................................................................................................225
Collections .........................................................................................................225
For Each and IEnumerable ..............................................................................226
Chapter 6 Event Handling and Delegates ............................237
Event Handling from an OOP Point of View ..........................................237
What Goes into the Functions Called by Events? ..........................................239
Basic Event Raising ........................................................................................241
Hooking Up the Listener Objects to Event Source Objects ..........................243
Building Your Own Event Classes ...................................................................247
Dynamic Event Handling ................................................................................249
Handling Events in an Inheritance Chain ......................................................253
Delegates ..............................................................................................................254
Building Up a Delegate ....................................................................................255
A More Realistic Example: Special Sorting .....................................................257
Delegates and Events .......................................................................................264
Chapter 7 Error Handling the VB .NET Way:
Living with Exceptions ...........................................265
Error Checking vs. Exception Handling .................................................266
First Steps in Exception Handling ...................................................................267
Analyzing the Exception ..................................................................................269
Multiple Catch Clauses ....................................................................................269
Throwing Exceptions ........................................................................................272
Exceptions in the Food Chain .........................................................................275
And Finally…Finally Blocks .........................................................................277
Some Tips for Using Exceptions ................................................................278
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