C# 6.0 Cookbook Jay Hilyard & Stephen Teilhet C# 6.0 Cookbook by Jay Hilyard and Stephen Teilhet Copyright © 2015 Jay Hilyard, Stephen Teilhet. All rights reserved. Printed in the United States of America. Published by O’Reilly Media, Inc., 1005 Gravenstein Highway North, Sebastopol, CA 95472. O’Reilly books may be purchased for educational, business, or sales promotional use. Online editions are also available for most titles (http://safaribooksonline.com). For more information, contact our corporate/institutional sales department: 800-998-9938 or [email protected]. Editor: Brian MacDonald Production Editor: Nicholas Adams Copyeditor: Rachel Monaghan Proofreader: Kim Cofer Indexer: Judith McConville Interior Designer: David Futato Cover Designer: Ellie Volckhausen Illustrator: Rebecca Demarest January 2004: First Edition January 2006: Second Edition December 2007: Third Edition October 2015: Fourth Edition Revision History for the Fourth Edition 2015-09-28: First Release See http://oreilly.com/catalog/errata.csp?isbn=9781491921463 for release details. The O’Reilly logo is a registered trademark of O’Reilly Media, Inc. C# 6.0 Cookbook, the cover image, and related trade dress are trademarks of O’Reilly Media, Inc. While the publisher and the authors have used good faith efforts to ensure that the information and instructions contained in this work are accurate, the publisher and the authors disclaim all responsibility for errors or omissions, including without limitation responsibility for damages resulting from the use of or reliance on this work. Use of the information and instructions contained in this work is at your own risk. If any code samples or other technology this work contains or describes is subject to open source licenses or the intellectual property rights of others, it is your responsibility to ensure that your use thereof complies with such licenses and/or rights. 978-1-4919-2146-3 [LSI] To Seth, Tom, Katie, and Jenna. Thank you for your friendship. Our lives are richer, happier, and more filled with laughter for having you in them. Jay Hilyard To my dear friend, pastor, and teacher, Damon Thomas. You and your family have been such a blessing to ours. Stephen Teilhet Preface C# is a language targeted at developers for the Microsoft .NET platform. Microsoft portrays C# as a modern and innovative language for .NET development and continues to deliver on that in C# 6.0 with features that help support dynamic programming, parallel programming, and writing less code. C# still allows for both declarative and functional styles of programming, and still includes great object-oriented features as well. In short, C# allows you to use the style of programming that fits your particular problem. We started writing this book together based on programming problems we ran into when we were first learning C#, and we have continued to expand it based on new challenges and capabilities in the language. In this edition, we have reworked the approach of many solutions to take advantage of the latest innovations in C# like the new expression-level (nameof, string interpolation, null conditional, index initializers), member declaration (auto-property initializers, getter-only auto-properties, expression-bodied function members), and statement-level (exception filters) features. We have also incorporated new uses of dynamic programming (C# 4.0) and asynchronous programming (C# 5.0) into both existing and new recipes to help you understand how to use these language features. We hope that these additions will help you get past some of the common (and not-so- common) pitfalls and questions everyone has when learning C# for the first time, exploring a new capacity of the language, or working on the slightly off-the-beaten-path items that come up during a development cycle. There are recipes addressing things we found missing from the .NET Framework Class Library (FCL), even though Microsoft has provided tons of functionality to keep folks from reinventing the wheel. Some of these solutions you might immediately use, and some may never darken your door, but we hope this book helps you get the most out of C# and the .NET Framework. The book is laid out with respect to the types of problems you will solve as you progress through your life as a C# programmer. These solutions are called recipes; each recipe consists of a single problem, its solution, a discussion of the solution and other relevant related information, and finally, a list of resources such as where in the FCL you can find more information about the classes used, other books addressing the topic, related articles, and other recipes. The question/answer format provides complete solutions to problems, making the book easy to read and use. Nearly every recipe contains a complete, documented code sample, showing you how to solve the specific problem, as well as a discussion of how the underlying technology works and a list of alternatives, limitations, and other considerations when appropriate.