Mark Michaelis - Essential C# 6.0

ePUB is an open, industry-standard format for eBooks. However, support of ePUB and its many features varies across reading devices and applications. Use your device or app settings to customize the presentation to your liking. Settings that you can customize often include font, font size, single or double column, landscape or portrait mode, and figures that you can click or tap to enlarge. For additional information about the settings and features on your reading device or app, visit the device manufacturers Web site.

Many titles include programming code or configuration examples. To optimize the presentation of these elements, view the eBook in single-column, landscape mode and adjust the font size to the smallest setting. In addition to presenting code and configurations in the reflowable text format, we have included images of the code that mimic the presentation found in the print book; therefore, where the reflowable format may compromise the presentation of the code listing, you will see a Click here to view code image link. Click the link to view the print-fidelity code image. To return to the previous page viewed, click the Back button on your device or app.

Mark Michaelis
with Eric Lippert

New York Boston Indianapolis San Francisco
Toronto Montreal London Munich Paris Madrid
Capetown Sydney Tokyo Singapore Mexico City

Microsoft, Windows, Visual Basic, Visual C#, and Visual C++ are either registered trademarks or trademarks of Microsoft Corporation in the U.S.A. and/or other countries/regions.

Many of the designations used by manufacturers and sellers to distinguish their products are claimed as trademarks. Where those designations appear in this book, and the publisher was aware of a trademark claim, the designations have been printed with initial capital letters or in all capitals.

The authors and publisher have taken care in the preparation of this book, but make no expressed or implied warranty of any kind and assume no responsibility for errors or omissions. No liability is assumed for incidental or consequential damages in connection with or arising out of the use of the information or programs contained herein.

For information about buying this title in bulk quantities, or for special sales opportunities (which may include electronic versions; custom cover designs; and content particular to your business, training goals, marketing focus, or branding interests), please contact our corporate sales department at or (800) 382-3419.

For government sales inquiries, please contact .

For questions about sales outside the U.S., please contact .

Visit us on the Web: informit.com/aw

Library of Congress Cataloging-in-Publication Data

Michaelis, Mark.
Essential C# 6.0 / Mark Michaelis with Eric Lippert.
pages cm
Includes index.
ISBN 978-0-13-414104-6 (pbk. : alk. paper) ISBN 0-13-414104-0 (pbk. : alk. paper)
1. C# (Computer program language) 2. Microsoft .NET Framework. I. Lippert, Eric, author. II. Title.
QA76.73.C154M5239 2016
005.133dc23
2015025757

Copyright 2016 Pearson Education, Inc.

All rights reserved. Printed in the United States of America. This publication is protected by copyright, and permission must be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, or likewise. To obtain permission to use material from this work, please submit a written request to Pearson Education, Inc., Permissions Department, 200 Old Tappan Road, Old Tappan, New Jersey 07657, or you may fax your request to (201) 236-3290.

ISBN-13: 978-0-13-414104-6
ISBN-10: 0-13-414104-0
Text printed in the United States on recycled paper at Edwards Brothers Malloy in Ann Arbor, Michigan First printing, September 2015

To my family: Elisabeth, Benjamin, Hanna, and Abigail.

You have sacrificed a husband and daddy for countless hours of writing,
frequently at times when he was needed most.

Thanks!

Welcome to one of the greatest collaborations you could dream of in the world of C# booksand probably far beyond! Mark Michaelis Essential C# series was already a classic when, for the previous edition, he teamed up with famous C# blogger Eric Lipperta masterstroke.

You may think of Eric as writing blogs and Mark as writing books, but that is not how I first got to know them.

In 2005 when LINQ (Language Integrated Query) was disclosed, I had only just joined Microsoft, and I got to tag along to the PDC conference for the big reveal. Despite my almost total lack of contribution to the technology, I thoroughly enjoyed the hype. The talks were overflowing, the printed leaflets were flying like hotcakes. It was a big day for C# and .NET, and I was having a great time.

It was pretty quiet in the hands-on labs area, though, where people could try out the technology preview themselves with nice, scripted walkthroughs. Thats where I ran into Mark. Needless to say, he wasnt following the script. He was doing his own experiments, combing through the docs, talking to other folks, and busily pulling together his own picture.

As a newcomer to the C# community, I think I may have met a lot of people for the first time at that conferencepeople with whom I have since formed great relationships. But to be honest, I dont remember itits all a blur. The only one I remember is Mark. Here is why: When I asked him if he was liking the new stuff, he didnt just join the rave. He was totally level-headed: I dont know yet. I havent made up my mind about it. He wanted to absorb and understand the full package, and until then he wasnt going to let anyone tell him what to think.

So instead of the quick sugar-rush of affirmation I might have expected, I got to have a frank and wholesome conversationthe first of many over the yearsabout details, consequences, and concerns with this new technology. And so it remains: Mark is an incredibly valuable community member for us language designers to have, because he is super smart, insists on understanding everything to the core, and has phenomenal insight into how things affect real developers. But perhaps most of all because he is forthright and never afraid to speak his mind. If something passes the Mark Test, then we know we can start feeling pretty good about it!

These are the same qualities that make Mark such a great writer. He goes right to the essence and communicates with great integrity, no sugarcoating, and a keen eye for practical value and real-world problems.

Eric is, of course, my former colleague of seven years on the C# team. Hed been there much longer than I had, and the first I recall of him, he was explaining to the team how to untangle a bowl of spaghetti. More precisely, our C# compiler code base at the time was in need of some serious architectural TLC and was exceedingly hard to add new features tosomething we desperately needed to be able to do with LINQ. Eric had been investigating what kind of architecture we ought to have (Phases! We didnt even really have those!), and more importantly, how to get from here to there, step by step. The remarkable thing was that as complex as this was, and as new as I was to the team and the code base, I immediately understood what he was saying!