From the Publisher
“Shining a bright light into many of the dark corners of C# 3.0, this book not only covers the ‘how,’ but also the ‘why,’ arming the reader with many field-tested methods for wringing the most from the new language features, such as LINQ, generics, and multithreading. If you are serious about developing with the C# language, you need this book.”
—Bill Craun, Principal Consultant, Ambassador Solutions, Inc.
“More Effective C# is an opportunity to work beside Bill Wagner. Bill leverages his knowledge of C# and distills his expertise down to some very real advice about programming and designing applications that every serious Visual C# user should know. More Effective C# is one of those rare books that doesn’t just regurgitate syntax, but teaches you how to use the C# language.”
—Peter Ritchie, Microsoft MVP: Visual C#
“More Effective C# is a great follow-up to Bill Wagner’s previous book. The extensive
C# 3.0 and LINQ coverage is extremely timely!”
—Tomas Restrepo, Microsoft MVP: Visual C++, .NET, and Biztalk Server
“As one of the current designers of C#, it is rare that I learn something new about the language by reading a book. More Effective C# is a notable exception. Gently blending concrete code and deep insights, Bill Wagner frequently makes me look at C# in a fresh light—one that really makes it shine. More Effective C# is at the surface a collection of very useful guidelines. Look again. As you read through it, you’ll find that you acquire more than just the individual pieces of advice; gradually you’ll pick up on an approach to programming in C# that is thoughtful, beautiful, and deeply pleasant. While you can make your way willy-nilly through the individual guidelines, I do recommend reading the whole book—or at least not skipping over the chapter introductions before you dive into specific nuggets of advice. There’s perspective and insight to be found there that in itself can be an important guide and inspiration for your future adventures in C#.”
—Mads Torgersen, Program Manager, Visual C#, Microsoft
“Bill Wagner has written an excellent book outlining the best practices for developers who work with the C# language. By authoring More Effective C#, he has again established himself as one of the most important voices in the C# community. Many of us already know how to use C#. What we need is advice on how to hone our skills so that we can become wiser programmers. There is no more sophisticated source of information on how to become a first-class C# developer than Bill Wagner’s book. Bill is intelligent, thoughtful, experienced, and skillful. By applying the lessons from this book to your own code, you will find many ways to polish and improve the work that you produce.”
—Charlie Calvert, Community Program Manager, Visual C#, Microsoft
Read an Excerpt
When Anders Hejlsberg first showed Language-Integrated Query (LINQ) to the world at the 2005 Professional Developers Conference (PDC), the C# programming world changed. LINQ justified several new features in the C# language: extension methods, local variable type inference, lambda expressions, anonymous types, object initializers, and collection initializers. C# 2.0 set the stage for LINQ by adding generics, iterators, static classes, nullable types, property accessor accessibility, and anonymous delegates. But all these features are useful outside LINQ: They are handy for many programming tasks that have nothing to do with querying data sources.
This book provides practical advice about the features added to the C# programming language in the 2.0 and 3.0 releases, along with advanced features that were not covered in my earlier Effective C#: 50 Specific Ways to Improve Your C# (Addison-Wesley, 2004). The items in More Effective C# reflect the advice I give developers who are adopting C# 3.0 in their professional work. There’s a heavy emphasis on generics, an enabling technology for everything in C# 2.0 and 3.0. I discuss the new features in C# 3.0; rather than organize the topics by language feature, I present these tips from the perspective of recommendations about the programming problems that developers can best solve by using these new features.
Consistent with the other books in the Effective Software Development Series, this book contains self-contained items detailing specific advice about how to use C#. The items are organized to guide you from using C# 1.x to using C# 3.0 in the best way.
Generics are an enabling technology for all new idioms that are part of C# 3.0. Although only the first chapter specifically addresses generics, you’ll find that they are an integral part of almost every item. After reading this book, you’ll be much more comfortable with generics and metaprogramming.
Of course, much of the book discusses how to use C# 3.0 and the LINQ query syntax in your code. The features added in C# 3.0 are very useful in their own right, whether or not you are querying data sources. These changes in the language are so extensive, and LINQ is such a large part of the justification for those changes, that each warrants its own chapter. LINQ and C# 3.0 will have a profound impact on how you write code in C#. This book will make that transition easier.
Who Should Read This Book?
This book was written for professional software developers who use C#. It assumes that you have some familiarity with C# 2.0 and C# 3.0. Scott Meyers counseled me that an Effective book should be a developer’s second book on a subject. This book does not include tutorial information on the new language features added as the language has evolved. Instead, I explain how you can integrate these features into your ongoing development activities. You’ll learn when to leverage the new language features in your development activities, and when to avoid certain practices that will lead to brittle code.
In addition to some familiarity with the newer features of the C# language, you should have an understanding of the major components that make up the .NET Framework: the .NET CLR (Common Language Runtime), the .NET BCL (Base Class Library), and the JIT (Just In Time) compiler. This book doesn’t cover .NET 3.0 components, such as WCF (Windows Communication Foundation), WPF (Windows Presentation Foundation), and WF (Windows Workflow Foundation). However, all the idioms presented apply to those components as well as any other .NET Framework components you happen to prefer.
About the Content
Generics are the enabling technology for everything else added to the C# language since C# 1.1. Chapter 1 covers generics as a replacement for System.Object and casts and then moves on to discuss advanced techniques such as constraints, generic specialization, method constraints, and backward compatibility. You’ll learn several techniques in which generics will make it easier to express your design intent.
Multicore processors are already ubiquitous, with more cores being added seemingly every day. This means that every C# developer needs to have a solid understanding of the support provided by the C# language for multithreaded programming. Although one chapter can’t cover everything you need to be an expert, Chapter 2 discusses the techniques you’ll need every day when you write multithreaded applications.
Chapter 3 explains how to express modern design idioms in C#. You’ll learn the best way to express your intent using the rich palette of C# language features. You’ll see how to leverage lazy evaluation, create composable interfaces, and avoid confusion among the various language elements in your public interfaces.
Chapter 4 discusses how to use the enhancements in C# 3.0 to solve the programming challenges you face every day. You’ll see when to use extension methods to separate contracts from implementation, how to use C# closures effectively, and how to program with anonymous types.
Chapter 5 explains LINQ and query syntax. You’ll learn how the compiler maps query keywords to method calls, how to distinguish between delegates and expression trees (and convert between them when needed), and how to escape queries when you’re looking for scalar results.
Chapter 6 covers those items that defy classification. You’ll learn how to define partial classes, work with nullable types, and avoid covariance and contravariance problems with array parameters.
Regarding the Sample Code
The samples in this book are not complete programs. They are the smallest snippets of code possible that illustrate the point. In several samples the method names substitute for a concept, such as AllocateExpensiveResource(). Rather than read pages of code, you can grasp the concept and quickly apply it to your professional development. Where methods are elided, the name implies what’s important about the missing method.
In all cases, you can assume that the following namespaces are specified:
Where types are used from other namespaces, I’ve explicitly included the namespace in the type.
In the first three chapters, I often show C# 2.0 and C# 3.0 syntax where newer syntax is preferred but not required. In Chapters 4 and 5 I assume that you would use the 3.0 syntax.