2006 oreilly c sharp cookbook, 2nd edition

Nearly every solution, or "recipe," contains a complete, documented code sample showing you how to solve the specific problem, as well as a detailed discussion of how and why the underli

By Jay Hilyard, Stephen Teilhet

Publisher: O'Reilly Pub Date: January 2006 Print ISBN-10: 0-596-10063-9 Print ISBN-13: 978-0-59-610063-6 Pages: 1184

Table of Contents | Index

With C# Cookbook, 2nd Edition, you'll be able to learn and improve your mastery of both

the C# language and the NET platform This updated bestseller has been completely revised to account for C# 2.0, the latest version of this popular object-oriented

programming language It also includes more than 100 new code solutions (over 300 overall) to common problems and tasks that you're sure to face as a C# programmer

Nearly every solution, or "recipe," contains a complete, documented code sample showing you how to solve the specific problem, as well as a detailed discussion of how and why the underling technology works This question-solution-discussion format is a proven teaching method, as any fan of O'Reilly's "Cookbook" series can attest to In fact, no other source offers a learn-as-you-go format quite like this.

By Jay Hilyard, Stephen Teilhet

Publisher: O'Reilly Pub Date: January 2006 Print ISBN-10: 0-596-10063-9 Print ISBN-13: 978-0-59-610063-6 Pages: 1184

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[M]

C# is a language targeted at developers for the Microsoft NETplatform who have already worked with a C-like language such

as C, C++, or Java Unlike previous versions of C or C++ forthe Microsoft Windows platform, C# code runs under a

managed execution environment While C and C++ developers

using Visual Studio NET can write managed code using

Managed C++, C# offers a middle path between C++'s overallpower but sometimes difficult code and the higher-level taskorientation provided by Visual Basic NET Microsoft portrays C#

as a modern and innovative language for NET developmentthat will be familiar to current C++ programmers while allowingmore runtime control over the executing code

C# allows you to perform many C/C++-like functions such asdirect memory access via pointers and operator overloadingthat are not supported in Visual Basic NET C# is the system-level programming language for NET You can still do great

application-level work in C#, but it really shines when you need

to build code a little closer to the Framework

If you have seen C#, you may have noticed that it looks a lotlike Java; Java programmers will feel very much at home in C#once they learn the Framework SDK C# can also be a greatlanguage for Visual Basic NET programmers when they need alittle more control over what the code is doing and don't want tohave to write C++ to gain an advantage On the Web, you'll find

a large community of people doing really neat things with C#and tons of sample code on sites such as

http://www.gotdotnet.com, http://www.codeproject.com, and

http://www.4guysfromrolla.com

We put this book together based on programming problems weran into when we were first learning C# as well as during ourcontinued use of it Since the first edition we have encountered

it will help you get past some of the common (and not-so-common) pitfalls and initial questions everyone has when

learning a new language as well as the slightly off the beatenpath items that come up during a development cycle There arerecipes dealing with things we found missing from the NET

Framework Class Library (FCL), even though Microsoft has

provided tons of functionality to keep folks from reinventing thewheel Some of these solutions you might immediately use andsome may never darken your door, but we hope this book helpsyou get the most out of C# and the NET Framework

The book is laid out with respect to the types of problems youwill 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 thesolution and other relevant related information, and finally

where you can look for more information about the classes usedfrom the FCL, other books addressing this topic, related articles,and other recipes The question-answer format provides

complete solutions to problems, making the book easy to readand use Nearly every recipe contains a complete, documentedcode sample showing you how to solve the specific problem, aswell as a discussion of how the underlying technology worksand a list of alternatives, limitations, and other considerationswhen appropriate

You don't have to be an experienced C# or NET developer touse this bookit is designed for users of all levels This book

provides solutions to problems that developers face every day

as well as some that may come along infrequently The recipesare targeted at the real-world developer who needs to solveproblems now, not learn lots of theory first before being able tosolve the problem While reference or tutorial books can teachgeneral concepts, they do not generally provide the help youneed in solving real-world problems We chose to teach by

To save you even the effort of typing in the solution, we providethe sample code for the book on the O'Reilly web site to

facilitate the "editor inheritance" mode of development (copyand paste) as well as to help less experienced developers seegood programming practice in action The sample code provides

a running test harness that exercises each of the solutions, butenough of the code is provided in each solution in the book toallow you to implement the solution without the sample code.The sample code is available from the book's catalog page:

http://www.oreilly.com/catalog/csharpckbk2

To run the samples in this book, you need a computer runningWindows 2000 or later (if you are using Windows NT 4.0, youcan use many, but not all, of the examples in this book; inparticular, ASP.NET and NET Web Services do not run on NT4.0) A few of the networking and XML solutions require

Microsoft Internet Information Server (IIS) Version 5 or later

To open and compile the samples in this book, you need VisualStudio NET 2005 If you are proficient with the downloadableFramework SDK and its command-line compilers, you shouldnot have any trouble following the text of this book and thecode samples

The solutions in this book are developed using Visual Studio.NET 2005 The differences between Version 2.0 and Version1.1 of the NET Framework are significant and the sample codehas changed from the first edition to reflect that A complete list

of differences between Version 2.0 and Version 1.1 of the NETFramework can be found at

http://www.gotdotnet.com/team/upgrade/apiChanges.aspx

This book is organized into 20 chapters, each of which focuses

on a particular topic in creating C# solutions The followingparagraphs summarize each chapter to give you an overview ofthis book's contents:

Chapter 1, Numbers and Enumerations

This chapter focuses on the numeric and enumeration datatypes used in C# code Recipes cover such things as

numeric conversions, using bitwise operators on numbers,and testing strings to determine whether they contain anumeric value The display, conversion, and testing of

enumeration types and recipes on using enumerations thatconsist of bit flags are also shown

Chapter 2, Strings and Characters

This chapter covers both the String and Char data types.Various recipes show how to compare strings in variousways, encode/decode strings, break strings apart, and putthem back together again, to name a few

Chapter 3, Classes and Structures

This large chapter contains recipes dealing with both classand structure data types This chapter covers a wide range

of recipes from design patterns to converting a class tointeroperating with COM

This is a new chapter focusing on the new generics capacity

in C#, which allows you to have code operate uniformly onvalues of different types There are recipes to help yourgeneral understanding of generics as well as when they areappropriate to use, what support is provided in the

Framework for them, and how to create custom

implementations of collections using generics

Chapter 5, Collections

This chapter examines recipes that make use of collections.The collection recipes make use ofas well as extend thefunctionality ofthe array (single, multi, and jagged), the

List<T>, and the Hashtable The new generic-based collectionsare explored, and the various ways to create your own

strongly typed collection are also discussed

Chapter 6, Iterators and Partial Types

In this chapter, two of the new features of C# are used tosolve very different programming problems We show howyou can implement iterators for generic and nongenerictypes and implement foreach functionality using iterators, aswell as custom iterator implementations The other feature

of C# in this chapter is partial types We show how you canuse partial types to do things like better segment your codeand how to generate code that is more easily extensible

Chapter 7, Exception Handling

implement exception handling in your application

Preventing unhandled exceptions, reading and displayingstack traces, and throwing/rethrowing exceptions are

included recipes In addition, specific recipes show how toovercome some tricky situations, such as exceptions fromlate-bound called methods, and how to build a custom

exception visualizer for the debugger

Chapter 8, Diagnostics

This chapter explores recipes that use data types that fallunder the System.Diagnostics namespace Recipes deal withthe trace/Debug classes, event logs, processes, performancecounters, and custom debugger displays for your types

Chapter 9, Delegates, Events, and Anonymous Methods

This chapter's recipes show how delegates, events, andanonymous methods can be used in your applications

Recipes allow manipulation of delegates that call more thanone method, synchronous delegates, asynchronous

delegates, and Windows keyboard hooks Anonymous

methods are explored and recipes show their usage in place

of old-style delegates as well as their use in implementingclosures and functors

Chapter 10, Regular Expressions

This chapter covers a very useful set of classes that areused to run regular expressions against strings Recipesenumerate regular expression matches, break up stringsinto tokens, find/replace characters, and verify the syntax

Chapter 12, Filesystem I/O

This chapter deals with filesystem interactions in four

distinct ways The first way is to look at typical file

based interactions; the third way deals with paths and

interactions; the second way looks at directory-or folder-temporary files; and the fourth way deals with advancedfilesystem I/O topics

configuration Among the recipes in this chapter are usingthe new web browser control and setting up caching

Chapter 16, Networking

This chapter explores the connectivity options provided bythe NET Framework and how to programmatically accessnetwork resources Recipes for using TCP/IP directly, namedpipes for communication, building your own port scanner,and more are covered here

Chapter 17, Security

There are many ways to write secure code and protect datausing the NET Framework, and in this chapter, we exploreareas such as controlling access to types, encryption anddecryption, random numbers, securely storing data, andusing programmatic and declarative security

This chapter discusses how C# allows you to step outside ofthe safe environment of managed code and write code that

is considered unsafe by the NET Framework The

possibilities and restrictions of using unsafe code in C# areaddressed by illustrating solutions to problems using unsafecode

Chapter 20, Toolbox

This chapter has recipes for those random sorts of

operations that developers run into over and over again,like determining locations of system resources, sending

email, and working with services It also covers some lessfrequently accessed but helpful application pieces like

message queuing, running code in a separate AppDomain,and finding the versions of assemblies in the GAC

In some cases, certain recipes are related In these cases, theSee Also section of the recipe as well as some text in the

Discussion will note the relationships

This book uses the following typographic conventions:

Italic

Used for URLs, names of directories and files, options, andoccasionally for emphasis

Constant width

Used for program listings and for code items such as

commands, options, switches, variables, attributes, keys,functions, types, classes, namespaces, methods, modules,properties, parameters, values, objects, events, eventhandlers, XML tags, HTML tags, macros, the contents offiles, and the output from commands

Constant width bold

Used in program listings to highlight an important part ofthe code

//…

Ellipses in C# code indicate text that has been omitted forclarity

Ellipses in XML Schemas and documents' code indicate textthat has been omitted for clarity

This icon indicates a tip, suggestion, or general note.

This icon indicates a warning or caution.

Nearly every recipe in this book contains one or more code

samples These samples are included in a single solution andare pieces of code and whole projects that are immediately

usable in your application Most of the code samples are writtenwithin a class or structure, making it easier to use within yourapplications In addition to this, any using directives are includedfor each recipe so that you will not have to search for whichones to include in your code

Complete error handling is included only in critical areas, such

as input parameters This allows you to easily see what is

correct input and what is not Many recipes omit error handling.This makes the solution easier to understand by focusing on thekey concepts

This book is here to help you get your job done In general, youmay use the code in this book in your programs and

documentation You do not need to contact us for permissionunless you're reproducing a significant portion of the code Forexample, writing a program that uses several chunks of codefrom this book does not require permission Selling or

distributing a CD-ROM of examples from O'Reilly books does

require permission Answering a question by citing this bookand quoting example code does not require permission

Incorporating a significant amount of example code from this

book into your product's documentation does require

permission

We appreciate, but do not require, attribution An attributionusually includes the title, author, publisher, and ISBN For

example: "C# Cookbook, 2nd edition by Jay Hilyard and

10063-9."

Stephen Teilhet Copyright 2006 O'Reilly Media, Inc., 0-596-If you feel your use of code examples falls outside fair use orthe preceding permission, feel free to contact us at

permissions@oreilly.com

To comment or ask technical questions about this book, sendemail to:

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For more information about our books, conferences, ResourceCenters, and the O'Reilly Network, see our web site at:

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This book started for us after a long development cycle for anew product from Compuware called DevPartner

SecurityChecker Much was learned, and some of the conceptsfor recipes in this edition helped to build that product With theadvent of C# 2.0 and the new features in C#, we took the

opportunity to reexamine how we did things in the first edition

to see how we could improve the existing recipes as well aslearn better ways of accomplishing programming tasks with C#.During the process Jay moved on to other opportunities fromCompuware while Steve continued to help develop the

forthcoming version of SecurityChecker We have learned anincredible amount about C# and the Framework in general

while we worked hard to help bring you a better understanding

of how C# has evolved and how it can help you do your jobbetter in this edition

This book would have been impossible without the followingpeople and we'd like to acknowledge all of their efforts

Ralph Davis, our editor, who helped keep us on track, refereedthe technical discussions, and was a steadying influence on astormy project Thank you for all of your efforts during the

process and for your professionalism It was most appreciatedand impressive given the circumstances

Ian Griffiths and Nicholas Paldino, our technical editors, whogave us their honest takes on our efforts and made good

suggestions on how to make the recipes even better They

helped to make this an even better book and for that we thankthem."

From Jay Hilyard

stages of the book I enjoyed working with you again, eventhough most of it was on nights and weekends this time

Special thanks to my wife Brooke to whom I owe an immensedebt of gratitude for so many things You are a fabulous motherand an even better wife Who would have thought I would bethe one to write the "Cookbooks"? Thank you and I love you

My sons, Owen and Andrew, understood when Daddy couldn't

go to the beach and went to bed willingly on nights when I

needed them to the most I am truly blessed to have two finesons

Thanks to Phil and Gail for being there to help in ways that onlygrandparents can

Thanks for Matt Pietrek for helping to explain why the 2.0

Framework reacted as it did when I tried new things beforethere were many other resources available

Thanks to the Compuware gang of my era that helped produceDevPartner Studio and SecurityChecker My perspective on

development using NET was expanded greatly from my

discussions and experiences with all of you and I wish you allthe very best I say thank you to Steve Munyan, Barry

Tannenbaum, Craig Neth, Kit Von Sück, Bob Newton, Garry

Poegel, Katie King, Alice Pizzuto, Xin Li, Charles Kekeh, TomWagner, Bill Holmes, Jeff Simmons, Russ Osterlund, John Lyon-Smith, Katrina Lyon-Smith, Ian Goodsell, Rich Chiodo, AndyNajberg, Bob Crowling, and everyone else

Thanks to Patrick Hynds, Duane LaFlotte, and Naveen Kohli forhelping to keep my NET interest high

Thanks to Tim Pelletier, Scott Cronshaw, Lance Simpson, DavidBennett, Suzanne Gibson, Kate Keisling, and Shawn McGowan

is yet to come

Thanks to Kristen Acheson for being a great friend and a fan

Finally, thanks again to my family and friends for asking about abook they don't understand and for being excited for me

From Steve Teilhet

I'm proud to count Jay Hilyard as a good friend, excellent

coworker, and hardworking coauthor It's not every day that youfind a person who is not only a good friend, but you also work

worked in real-world applications

Thanks to the SecurityChecker development team (and friends)who helped me expand my knowledge of C# and also helped

me through the rough patches: Garry Poegel, Andrew Fournier,Katie King, Kelley-Sue LeBlanc, Xin Li, Alicia Rhoades, Tom

Wagner, Tim Weaver, Dave Chestnutt, Steve Munyan, Bob

Newton, Charles Kekeh, Barry Tannenbaum, and Dennis

Murphy Thanks for all your help and supportI think this calls for

a celebration.

Introduction

Recipe 1.1 Determining Approximate Equality Between aFraction and Floating-Point Value

Recipe 1.2 Converting Degrees to Radians

Recipe 1.3 Converting Radians to Degrees

Recipe 1.4 Using the Bitwise Complement Operator withVarious Data Types

Recipe 1.5 Testing for an Even or Odd Value

Recipe 1.6 Obtaining the High Word or Low Word of aNumber

Recipe 1.22 Determining the Integral Part of a Decimal orDouble