Illustrated C# 7: The C# Language Presented Clearly, Concisely, and Visually

817 Pages·2018·34.96 MB·English

by  Daniel Solis

Illustrated C# 7
The C# Language Presented Clearly,
Concisely, and Visually
—
Fifth Edition
—
Daniel Solis
Cal Schrotenboer
Illustrated C# 7
The C# Language Presented Clearly,
Concisely, and Visually
Fifth Edition
Daniel Solis
Cal Schrotenboer
Illustrated C# 7
Daniel Solis Cal Schrotenboer
SAN JOSE, California, USA Kissimmee, Florida, USA
ISBN-13 (pbk): 978-1-4842-3287-3 ISBN-13 (electronic): 978-1-4842-3288-0
https://doi.org/10.1007/978-1-4842-3288-0
Library of Congress Control Number: 2018934213
Copyright © 2018 by Daniel Solis and Cal Schrotenboer
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This book is dedicated to Sian and Galen.
—Dan
This book is dedicated to Paul, Kristin, and Alison.
—Cal
Contents
About the Authors ������������������������������������������������������������������������������������������������xxvii
About the Technical Reviewers ����������������������������������������������������������������������������xxix
Acknowledgments ������������������������������������������������������������������������������������������������xxxi
Introduction ��������������������������������������������������������������������������������������������������������xxxiii
■ Chapter 1: C# and the �NET Framework �����������������������������������������������������������������1
Before .NET ......................................................................................................................2
Windows Programming in the Late 1990s ..............................................................................................2
Goals for the Next-Generation Platform Services ...................................................................................2
Enter Microsoft .NET ........................................................................................................3
Components of the .NET Framework ......................................................................................................3
An Improved Programming Environment ................................................................................................4
Compiling to the Common Intermediate Language ..........................................................7
Compiling to Native Code and Execution..........................................................................8
Overview of Compilation and Execution .................................................................................................9
The Common Language Runtime ...................................................................................10
The Common Language Infrastructure ...........................................................................11
Important Parts of the CLI .....................................................................................................................12
Review of the Acronyms .................................................................................................13
The Evolution of C# ........................................................................................................14
C# and the Evolution of Windows ...................................................................................15
v
■ Contents
■ Chapter 2: C# and �NET Core ��������������������������������������������������������������������������������17
The .NET Framework Background ..................................................................................18
Why .NET Core (and Xamarin)? ......................................................................................18
Goals of .NET Core ..........................................................................................................19
Multiplatform Support ....................................................................................................20
Rapid Development and Upgrades .................................................................................20
Smaller Application Footprints, Simpler Deployment,
and Reduced Versioning Problems .................................................................................20
Open Source Community Support ..................................................................................21
Improved Application Performance ................................................................................21
Fresh Start ......................................................................................................................21
The Development of .NET Core .......................................................................................22
Where Does This Leave the .NET Framework? ...............................................................22
Where Does Xamarin Fit In? ...........................................................................................22
■ Chapter 3: Overview of C# Programming ������������������������������������������������������������23
A Simple C# Program .....................................................................................................24
More About SimpleProgram ..................................................................................................................25
Identifiers .......................................................................................................................26
Keywords ........................................................................................................................27
Main: The Starting Point of a Program ...........................................................................28
Whitespace .....................................................................................................................28
Statements .....................................................................................................................29
Blocks ...................................................................................................................................................29
Text Output from a Program ...........................................................................................30
Write .....................................................................................................................................................30
WriteLine ..............................................................................................................................................30
The Format String .................................................................................................................................31
Multiple Markers and Values ................................................................................................................33
Formatting Numeric Strings .................................................................................................................34
vi
■ Contents
Comments: Annotating the Code ....................................................................................40
More About Comments .........................................................................................................................41
Documentation Comments ...................................................................................................................41
Summary of Comment Types ................................................................................................................42
■ Chapter 4: Types, Storage, and Variables ������������������������������������������������������������43
A C# Program Is a Set of Type Declarations ...................................................................44
A Type Is a Template .......................................................................................................45
Instantiating a Type ........................................................................................................45
Data Members and Function Members ..........................................................................46
Types of Members ................................................................................................................................46
Predefined Types ............................................................................................................47
More About the Predefined Types .........................................................................................................48
User-Defined Types.........................................................................................................49
The Stack and the Heap .................................................................................................50
The Stack ..............................................................................................................................................50
The Heap ..............................................................................................................................................51
Value Types and Reference Types ..................................................................................52
Storing Members of a Reference Type Object ......................................................................................52
Categorizing the C# Types ....................................................................................................................53
Variables .........................................................................................................................54
Variable Declarations ............................................................................................................................54
Multiple-Variable Declarations .............................................................................................................56
Using the Value of a Variable ................................................................................................................56
Static Typing and the dynamic Keyword ........................................................................57
Nullable Types ................................................................................................................57
■ Chapter 5: Classes: The Basics ����������������������������������������������������������������������������59
Overview of Classes .......................................................................................................60
A Class Is an Active Data Structure ......................................................................................................60
Programs and Classes: A Quick Example .......................................................................61
Declaring a Class ............................................................................................................62
vii
■ Contents
Class Members ...............................................................................................................63
Fields ....................................................................................................................................................63
Methods ................................................................................................................................................65
Creating Variables and Instances of a Class ..................................................................66
Allocating Memory for the Data .....................................................................................67
Combining the Steps ............................................................................................................................68
Instance Members ..........................................................................................................69
Access Modifiers ............................................................................................................70
Private and Public Access .....................................................................................................................70
Accessing Members from Inside the Class ....................................................................73
Accessing Members from Outside the Class ..................................................................74
Putting It All Together .....................................................................................................75
■ Chapter 6: Methods ���������������������������������������������������������������������������������������������77
The Structure of a Method .............................................................................................78
Code Execution in the Method Body ...............................................................................79
Local Variables ...............................................................................................................80
Type Inference and the var Keyword ....................................................................................................81
Local Variables Inside Nested Blocks ...................................................................................................82
Local Constants ..............................................................................................................83
Flow of Control ...............................................................................................................84
Method Invocations ........................................................................................................85
Return Values .................................................................................................................86
The Return Statement and Void Methods .......................................................................88
Local Functions ..............................................................................................................90
Parameters .....................................................................................................................91
Formal Parameters ...............................................................................................................................91
Actual Parameters ................................................................................................................................92
Value Parameters ...........................................................................................................94
Reference Parameters ....................................................................................................97
viii
■ Contents
Reference Types As Value and Reference Parameters .................................................100
Output Parameters .......................................................................................................104
Parameter Arrays..........................................................................................................108
Method Invocation ..............................................................................................................................109
Arrays As Actual Parameters ..............................................................................................................112
Summary of Parameter Types ......................................................................................112
Ref Local and Ref Return .............................................................................................113
Method Overloading .....................................................................................................117
Named Parameters ......................................................................................................118
Optional Parameters .....................................................................................................120
Stack Frames ...............................................................................................................124
Recursion .....................................................................................................................126
■ Chapter 7: More About Classes �������������������������������������������������������������������������129
Class Members .............................................................................................................130
Order of Member Modifiers ..........................................................................................130
Instance Class Members ..............................................................................................132
Static Fields ..................................................................................................................133
Accessing Static Members from Outside the Class .....................................................134
Example of a Static Field ....................................................................................................................135
Lifetimes of Static Members ..............................................................................................................136
Static Function Members .............................................................................................137
Other Static Class Member Types .................................................................................138
Member Constants .......................................................................................................139
Constants Are Like Statics ............................................................................................140
Properties .....................................................................................................................141
Property Declarations and Accessors .................................................................................................142
A Property Example ............................................................................................................................143
Using a Property .................................................................................................................................144
Properties and Associated Fields .......................................................................................................145
ix
■ Contents
Performing Other Calculations............................................................................................................147
Read-Only and Write-Only Properties .................................................................................................148
Properties vs. Public Fields ................................................................................................................148
An Example of a Computed, Read-Only Property ...............................................................................149
Automatically Implemented Properties—Auto-properties .................................................................150
Static Properties .................................................................................................................................151
Instance Constructors ..................................................................................................152
Constructors with Parameters ............................................................................................................153
Default Constructors ...........................................................................................................................154
Static Constructors .......................................................................................................155
Example of a Static Constructor .........................................................................................................156
Object Initializers ..........................................................................................................157
Destructors ...................................................................................................................158
The readonly Modifier ..................................................................................................159
The this Keyword ..........................................................................................................160
Indexers ..............................................................................................................................................162
What Is an Indexer? ............................................................................................................................163
Indexers and Properties ......................................................................................................................163
Declaring an Indexer ...........................................................................................................................164
The Indexer set Accessor....................................................................................................................165
The Indexer get Accessor ...................................................................................................................166
More About Indexers ...........................................................................................................................166
Declaring the Indexer for the Employee Example ...............................................................................167
Another Indexer Example....................................................................................................................168
Indexer Overloading ............................................................................................................................169
Access Modifiers on Accessors ....................................................................................170
Partial Classes and Partial Types ..................................................................................171
Partial Methods ............................................................................................................173
x