Professional C# 6 and .neT Core 1.0

inTroduCTion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . li

➤ ParT i The C# language

ChaPTer 1 .NET Application Architectures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

ChaPTer 2 Core C#  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

ChaPTer 3 Objects and Types  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

ChaPTer 4 Inheritance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

ChaPTer 5 Managed and Unmanaged Resources  . . . . . . . . . . . . . . . . . . . . . . 123

ChaPTer 6 Generics  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159

ChaPTer 7 Arrays and Tuples  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183

ChaPTer 8 Operators and Casts  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205

ChaPTer 9 Delegates, Lambdas, and Events  . . . . . . . . . . . . . . . . . . . . . . . . . . 243

ChaPTer 10 Strings and Regular Expressions  . . . . . . . . . . . . . . . . . . . . . . . . . . . 267

ChaPTer 11 Collections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287

ChaPTer 12 Special Collections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319

ChaPTer 13 Language Integrated Query  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339

ChaPTer 14 Errors and Exceptions  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371

ChaPTer 15 Asynchronous Programming   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 395

ChaPTer 16 Reflection, Metadata, and Dynamic Programming  . . . . . . . . . . . . 417

➤ ParT ii .neT Core and WindoWs runTime

ChaPTer 17 Visual Studio 2015 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 455

ChaPTer 18 .NET Compiler Platform   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 511

ChaPTer 19 Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 541

ChaPTer 20 Diagnostics and Application Insights  . . . . . . . . . . . . . . . . . . . . . . . 569

ChaPTer 21 Tasks and Parallel Programming  . . . . . . . . . . . . . . . . . . . . . . . . . . . 591

ChaPTer 22 Task Synchronization  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 613

ChaPTer 23 Files and Streams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 641

Continues

ChaPTer 24 Security  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 681

ChaPTer 25 Networking  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 703

ChaPTer 26 Composition  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 749

ChaPTer 27 XML and JSON   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 781

ChaPTer 28 Localization   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 819

➤ ParT iii WindoWs aPPs

ChaPTer 29 Core XAML  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 849

ChaPTer 30 Styling XAML Apps   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 871

ChaPTer 31 Patterns with XAML Apps  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 923

ChaPTer 32 Windows Apps: User Interfaces  . . . . . . . . . . . . . . . . . . . . . . . . . . . 951

ChaPTer 33 Advanced Windows Apps  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 991

ChaPTer 34 Windows Desktop Applications with WPF  . . . . . . . . . . . . . . . . . . 1035

ChaPTer 35 Creating Documents with WPF  . . . . . . . . . . . . . . . . . . . . . . . . . . . 1101

ChaPTer 36 Deploying Windows Apps  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1125

➤ ParT iv Web aPPliCaTions and serviCes

ChaPTer 37 ADO.NET  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1143

ChaPTer 38 Entity Framework Core  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1159

ChaPTer 39 Windows Services  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1189

ChaPTer 40 ASP.NET Core  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1219

ChaPTer 41 ASP.NET MVC  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1255

ChaPTer 42 ASP.NET Web API  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1311

ChaPTer 43 WebHooks and SignalR  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1337

ChaPTer 44 Windows Communication Foundation  . . . . . . . . . . . . . . . . . . . . . 1357

ChaPTer 45 Deploying Websites and Services  . . . . . . . . . . . . . . . . . . . . . . . . . 1401

index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1417

Professional

C# 6 and .neT Core 1.0

Professional

C# 6 and .neT Core 1.0

Christian Nagel

Professional C# 6 and .neT Core 1.0

Published by John Wiley & Sons, Inc. 10475 Crosspoint Boulevard Indianapolis, IN 46256 www.wiley.com

Copyright © 2016 by John Wiley & Sons, Inc., Indianapolis, Indiana

Published simultaneously in Canada

ISBN: 978-1-119-09660-3

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ISBN: 978-1-119-09663-4 (ebk)

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This book is dedicated to my family—Angela,

Stephanie, and Matthias—I love you all!

abouT The auThor 

ChrisTian nagel is Microsoft MVP for Visual Studio and Development Technologies, and has been Microsoft Regional Director for more than 15 years. Christian is an associate of thinktecture and founder of CN innovation, where he offers training and consulting on how to develop solutions using the Microsoft platform. He draws on more than 25 years of software development experience.

Christian started his computing career with PDP 11 and VAX/VMS systems at Digital Equipment Corporation, covering a variety of languages and platforms. Since 2000, when .NET was just a technology preview, he has been working with various technologies to build .NET solutions. Currently, he mainly coaches people

on development of Universal Windows Platform apps and ASP.NET MVC, using several Microsoft Azure service offerings.

Even after many years in software development, Christian still loves learning and using new technologies and teaching others how to use the new technologies in various forms. Using his profound knowledge of Microsoft technologies, he has written numerous books, and is certified as Microsoft Certified Trainer and Certified Solution Developer. Christian speaks at international conferences such as TechEd, BASTA!, and TechDays. He founded INETA Europe to support .NET user groups. You can contact Christian via his website www.cninnovation.com and follow his tweets at @christiannagel.

http://www.cninnovation.com

abouT The TeChniCal ediTor

isTván novák is an associate and the chief technology consultant with SoftwArt, a small Hungarian IT consulting company. He works as a software architect and community evangelist. In the last 25 years, he has participated in more than 50 enterprise software development projects. In 2002, he coauthored the first Hungarian book about .NET development. In 2007, he was awarded the Microsoft Most Valuable Professional (MVP) title, and in 2011 he became a Microsoft Regional Director. István coauthored Visual Studio 2010 and .NET 4 Six-in-One (Wiley, 2010) and Beginning Windows 8 Application Development (Wiley, 2012), and he authored Beginning Visual Studio LightSwitch Development (Wiley, 2011).

István holds master’s degree from the Technical University of Budapest, Hungary and also has a doctoral degree in software technology. He lives in Dunakeszi, Hungary, with his wife and two daughters. He is a passionate scuba diver. You may have a good chance of meeting him underwater in the Red Sea, any season of the year.

senior aCquisiTions ediTorKen Brown

ProjeCT ediTorCharlotte Kughen

TeChniCal ediTorIstván Novák

ProduCTion ediTorDassi Zeidel

manager of ConTenT develoPmenT & assemblyMary Beth Wakefield

ProduCTion manager Kathleen Wisor

markeTing direCTorDavid Mayhew

markeTing managerCarrie Sherrill

Professional TeChnology & sTraTegy direCTorBarry Pruett

business managerAmy Knies

assoCiaTe PublisherJim Minatel

ProjeCT CoordinaTor, CoverPatrick Redmond

ProofreaderAmy J. Schneider

indexerJohn Sleeva

Cover designerWiley

Cover image© Digital Storn/Shutterstock

CrediTs  

aCknoWledgmenTs 

i WanT To Thank Charlotte Kughen, who made my text so much more readable. Often I was working late at night writing while .NET Core was continuously evolving. Charlotte was of enormous help to change my ideas into great readable text. I’m almost sure that Charlotte now knows a lot more about programming than she would like to. Special thanks also goes to István Novák, who has authored several great books. Despite all the issues we had with the fast-evolving .NET Core and the interim builds I was using while working on the book, István challenged me to enhance the code samples that allow you—the reader—to better follow the flow. Thank you, Charlotte and István—you’ve been of great help for the quality of this book.

I also would like to thank Kenyon Brown and Jim Minatel and everyone else at Wiley who helped to get edition 10 of this great book to be published. I also want to thank my wife and children for supporting my writing. You understood and helped with the time I was working on the book, including evenings, nights, and weekends. Angela, Stephanie, and Matthias—you are my loved ones. This would not have been possible without you.

Contents

IntroductIon li

Part I: the C# Language

ChaPter 1: .net aPPLICatIon arChIteCtures 3

Choosing Your Technologies 3Reviewing .NET History 4

C# 1.0—A New Language 4C# 2 and .NET 2 with Generics 5.NET 3—Windows Presentation Foundation 6C# 3 and .NET 3.5—LINQ 6C# 4 and .NET 4—Dynamic and TPL 7C# 5 and Asynchronous Programming 7C# 6 and .NET Core 8Choosing Technologies and Going Forward 9

.NET 2015 10.NET Framework 4.6 10.NET Core 1.0 11Assemblies 12

Private Assemblies 12Shared Assemblies 13

NuGet Packages 13Common Language Runtime 14.NET Native 15Windows Runtime 15

Hello, World 16Compiling with .NET 4.6 17Compiling with .NET Core CLI 19

Setting Up the Environment 19Building the Application 19Packaging and Publishing the Application 22

Application Types and Technologies 23Data Access 23Windows Desktop Applications 24Universal Windows Platform 25SOAP Services with WCF 25

xviii

CONTENTS

Web Services with the ASP.NET Web API 26WebHooks and SignalR 26Windows Services 26Web Applications 27Microsoft Azure 27

Software as a Service 27Infrastructure as a Service 27Platform as a Service 27

Developer Tools 28Visual Studio Community 28Visual Studio Professional with MSDN 28Visual Studio Enterprise with MSDN 28Visual Studio Code 29

Summary 29

ChaPter 2: Core C#  31

Fundamentals of C# 32Creating Hello, World! with Visual Studio 32

Creating a Solution 32Creating a New Project 33Compiling and Running the Program 35Taking a Closer Look at the Code 37

Working with Variables 38Initializing Variables 39Using Type Inference 39Understanding Variable Scope 40

Scope Clashes for Local Variables 41Scope Clashes for Fields and Local Variables 42

Working with Constants 42Using Predefined Data Types 43

Value Types and Reference Types 43.NET Types 44Predefined Value Types 44

Integer Types 44Floating-Point Types 45The Decimal Type 46The Boolean Type 46The Character Type 46

Predefined Reference Types 47The object Type 47The string Type 47

xix

CONTENTS

Controlling Program Flow 49Conditional Statements 49

The if Statement 49The switch Statement 51

Loops 52The for Loop 52The while Loop 54The do. . .while Loop 54The foreach Loop 55

Jump Statements 55The goto Statement 55The break Statement 56The continue Statement 56The return Statement 56

Working with Enumerations 56Getting Organized with Namespaces 57

The using Directive 58Namespace Aliases 59

Understanding the Main Method 60Using Comments 61

Internal Comments Within the Source Files 61XML Documentation 62

Understanding C# Preprocessor Directives 63#define and #undef 63#if, #elif, #else, and #endif 64#warning and #error 65#region and #endregion 65#line 65#pragma 65

C# Programming Guidelines 66Rules for Identifiers 66Usage Conventions 67

Naming Conventions 68Use of Properties and Methods 70Use of Fields 70

Summary 71

ChaPter 3: objeCts and tyPes  73

Creating and Using Classes 74Classes and Structs 74Classes 75

xx

CONTENTS

Fields 76Properties 76

Auto-Implemented Properties 77Access Modifiers for Properties 77

Methods 78Declaring Methods 78Expression-Bodied Methods 79Invoking Methods 79Method Overloading 80Named Arguments 80Optional Arguments 81Variable Number of Arguments 82

Constructors 82Calling Constructors from Other Constructors 84Static Constructors 85

Readonly Members 87Readonly Fields 87Readonly Properties 88Auto-implemented Readonly Properties 88Expression-Bodied Properties 88Immutable Types 89

Anonymous Types 89Structs 90

Structs Are Value Types 91Structs and Inheritance 92Constructors for Structs 92

Passing Parameters by Value and by Reference 92ref Parameters 93out Parameters 94

Nullable Types 94Enumerations 95Partial Classes 97Extension Methods 99The Object Class 100Summary 101

ChaPter 4: InherItanCe 103

Inheritance 103Types of Inheritance 103

Multiple Inheritance 104Structs and Classes 104

xxi

CONTENTS

Implementation Inheritance 104Virtual Methods 105Polymorphism 107Hiding Methods 107Calling Base Versions of Methods 109Abstract Classes and Methods 109Sealed Classes and Methods 110Constructors of Derived Classes 111

Modifiers 113Access Modifiers 113Other Modifiers 114

Interfaces 115Defining and Implementing Interfaces 116Interface Inheritance 118

is and as Operators 120Summary 121

ChaPter 5: Managed and unManaged resourCes  123

Resources 123Memory Management Under the Hood 124

Value Data Types 124Reference Data Types 127Garbage Collection 129

Strong and Weak References 131Working with Unmanaged Resources 132

Destructors or Finalizers 133The IDisposable Interface 134The using Statement 135Implementing IDisposable and a Destructor 135IDisposable and Finalizer Rules 137

Unsafe Code 137Accessing Memory Directly with Pointers 138

Writing Unsafe Code with the unsafe Keyword 139Pointer Syntax 140Casting Pointers to Integer Types 141Casting Between Pointer Types 142void Pointers 142Pointer Arithmetic 142The sizeof Operator 144Pointers to Structs: The Pointer Member Access Operator 144Pointers to Class Members 145

xxii

CONTENTS

Pointer Example: PointerPlayground 146Using Pointers to Optimize Performance 150

Creating Stack-based Arrays 150QuickArray Example 153

Platform Invoke 154Summary 158

ChaPter 6: generICs  159

Generics Overview 159Performance 160Type Safety 161Binary Code Reuse 162Code Bloat 162Naming Guidelines 162

Creating Generic Classes 162Generics Features 166

Default Values 167Constraints 167Inheritance 170Static Members 171

Generic Interfaces 171Covariance and Contra-variance 172Covariance with Generic Interfaces 172Contra-Variance with Generic Interfaces 174

Generic Structs 174Generic Methods 177

Generic Methods Example 177Generic Methods with Constraints 178Generic Methods with Delegates 179Generic Methods Specialization 180

Summary 181

ChaPter 7: arrays and tuPLes  183

Multiple Objects of the Same and Different Types 183Simple Arrays 184

Array Declaration 184Array Initialization 184Accessing Array Elements 185Using Reference Types 186

Multidimensional Arrays 187Jagged Arrays 188

xxiii

CONTENTS

Array Class 189Creating Arrays 189Copying Arrays 190Sorting 191

Arrays as Parameters 194Array Covariance 194ArraySegment 194

Enumerators 195IEnumerator Interface 196foreach Statement 196yield Statement 197

Different Ways to Iterate Through Collections 199Returning Enumerators with Yield Return 200

Tuples 201Structural Comparison 202Summary 204

ChaPter 8: oPerators and Casts  205

Operators and Casts 205Operators 206

Operator Shortcuts 207The Conditional Operator (?:) 208The checked and unchecked Operators 209The is Operator 210The as Operator 210The sizeof Operator 210The typeof Operator 211The nameof Operator 211The index Operator 212Nullable Types and Operators 212The Null Coalescing Operator 213The Null Propagation Operator 214Operator Precedence and Associativity 215

Type Safety 216Type Conversions 217

Implicit Conversions 217Explicit Conversions 218

Boxing and Unboxing 220Comparing Objects for Equality 221

Comparing Reference Types for Equality 221The ReferenceEquals Method 221

xxiv

CONTENTS

The Virtual Equals Method 221The Static Equals Method 221Comparison Operator (==) 222

Comparing Value Types for Equality 222Operator Overloading 222

How Operators Work 223Operator Overloading Example: The struct Vector 224Overloading the Comparison Operators 228Which Operators Can You Overload? 230

Implementing Custom Index Operators 231User-Defined Casts 233

Implementing User-Defined Casts 234Casts Between Classes 237Casts Between Base and Derived Classes 238Boxing and Unboxing Casts 239

Multiple Casting 239Summary 242

ChaPter 9: deLegates, LaMbdas, and events  243

Referencing Methods 243Delegates 244

Declaring Delegates 245Using Delegates 246Simple Delegate Example 249Action and Func Delegates 250BubbleSorter Example 251Multicast Delegates 253Anonymous Methods 256

Lambda Expressions 258Parameters 258Multiple Code Lines 259Closures 259

Events 260Event Publisher 260Event Listener 262Weak Events 263

Summary 265

ChaPter 10: strIngs and reguLar exPressIons  267

Examining System.String 268Building Strings 269StringBuilder Members 272

xxv

CONTENTS

String Formats 273String Interpolation 273

FormattableString 273Using Other Cultures with String Interpolation 274Escaping Curly Brackets 275

DateTime and Number Formats 275Custom String Formats 276

Regular Expressions 277Introduction to Regular Expressions 278The RegularExpressionsPlayground Example 279Displaying Results 282Matches, Groups, and Captures 283

Summary 285

ChaPter 11: CoLLeCtIons 287

Overview 287Collection Interfaces and Types 288Lists 289

Creating Lists 290Collection Initializers 290Adding Elements 291Inserting Elements 291Accessing Elements 292Removing Elements 292Searching 293Sorting 295Read-Only Collections 296

Queues 296Stacks 300Linked Lists 302Sorted List 306Dictionaries 308

Dictionary Initializers 308Key Type 309Dictionary Example 310Lookups 313Sorted Dictionaries 314

Sets 314Performance 316Summary 318

xxvi

CONTENTS

ChaPter 12: sPeCIaL CoLLeCtIons 319

Overview 319Working with Bits 319

BitArray 320BitVector32 322

Observable Collections 324Immutable Collections 326

Using Builders with Immutable Collections 328Immutable Collection Types and Interfaces 328Using LINQ with Immutable Arrays 329

Concurrent Collections 329Creating Pipelines 330Using a BlockingCollection 333Using a ConcurrentDictionary 334Completing the Pipeline 335

Summary 336

ChaPter 13: Language Integrated Query  339

LINQ Overview 339Lists and Entities 340LINQ Query 343Extension Methods 343Deferred Query Execution 345

Standard Query Operators 347Filtering 348Filtering with Index 349Type Filtering 349Compound from 350Sorting 351Grouping 352Variables Within the LINQ Query 352Grouping with Nested Objects 353Inner Join 354Left Outer Join 355Group Join 356Set Operations 359Zip 360Partitioning 361Aggregate Operators 362Conversion Operators 363Generation Operators 365

xxvii

CONTENTS

Parallel LINQ 365Parallel Queries 365Partitioners 366Cancellation 367

Expression Trees 367LINQ Providers 370Summary 370

ChaPter 14: errors and exCePtIons  371

Introduction 371Exception Classes 372Catching Exceptions 374

Implementing Multiple Catch Blocks 376Catching Exceptions from Other Code 379System.Exception Properties 379Exception Filters 380Re-throwing Exceptions 381

Naïve Use to Rethrow the Exception 382Changing the Exception 383Rethrowing the Exception 384Using Filters to Add Functionality 384

What Happens If an Exception Isn’t Handled? 385User-Defined Exception Classes 385

Catching the User-Defined Exceptions 386Throwing the User-Defined Exceptions 388Defining the User-Defined Exception Classes 391

Caller Information 393Summary 394

ChaPter 15: asynChronous PrograMMIng   395

Why Asynchronous Programming Is Important 395Asynchronous Patterns 396

Synchronous Call 402Asynchronous Pattern 403Event-Based Asynchronous Pattern 405Task-Based Asynchronous Pattern 405

Foundation of Asynchronous Programming 407Creating Tasks 408Calling an Asynchronous Method 408Continuation with Tasks 409Synchronization Context 409

xxviii

CONTENTS

Using Multiple Asynchronous Methods 409Calling Asynchronous Methods Sequentially 409Using Combinators 410

Converting the Asynchronous Pattern 410Error Handling 411

Handling Exceptions with Asynchronous Methods 412Handling Exceptions with Multiple Asynchronous Methods 412Using AggregateException Information 413

Cancellation 414Starting a Cancellation 414Cancellation with Framework Features 415Cancellation with Custom Tasks 415

Summary 416

ChaPter 16: refLeCtIon, Metadata, and dynaMIC PrograMMIng  417

Inspecting Code at RunTime and Dynamic Programming 417Custom Attributes 418

Writing Custom Attributes 419Specifying the AttributeUsage Attribute 420Specifying Attribute Parameters 421Specifying Optional Attribute Parameters 421

Custom Attribute Example: WhatsNewAttributes 422The WhatsNewAttributes Library Assembly 422The VectorClass Assembly 423

Using Reflection 425The System.Type Class 425

Type Properties 425Methods 426

The TypeView Example 427The Assembly Class 429

Getting Details About Types Defined in an Assembly 430Getting Details About Custom Attributes 430

Completing the WhatsNewAttributes Example 431Using Dynamic Language Extensions for Reflection 435

Creating the Calculator Library 435Instantiating a Type Dynamically 436Invoking a Member with the Reflection API 438Invoking a Member with the Dynamic Type 439

The Dynamic Type 440Dynamic Behind the Scenes 441