Professional C Sharp Wrox pot

He has written XML Web Services for ASP.NET, Web Services Enhancements: Understanding the WSE for Enterprise Applications, Visual Basic .NET Bible, and ASP.NET Professional Secrets all p

Professional C# Third Edition

Simon Robinson Christian Nagel Jay Glynn Morgan Skinner Karli Watson Bill Evjen

Professional C# Third Edition

Professional C# Third Edition

Simon Robinson Christian Nagel Jay Glynn Morgan Skinner Karli Watson Bill Evjen

Professional C#, Third Edition

Copyright © 2004 by Wiley Publishing, Inc., Indianapolis, Indiana All rights reserved

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About the Authors

Simon Robinson Simon Robinson is the editor-in-chief of ASP Today, one of the leading sitesrelated to Web programming on the Windows platform

Simon’s first experience of commercial computer programming was in theearly 1980s, when a computer project he was working on at college becamethe school’s student timetabling program, running on the BBC Micro Later

he studied for a Ph.D in physics and subsequently spent a couple of yearsworking as a university physics researcher From there he moved on to work-ing as a computer programmer, then writing books about programming, andfinally on to his present job at ASP Today

He has an extremely broad experience of programming on Windows These days his core specialty is NETprogramming He is comfortable coding in C++, C#, VB, and IL, and has skills ranging from graphics andWindows Forms to ASP.NET to directories and data access to Windows services and the native Windows API.Simon lives in Lancaster, UK His outside interests include theater, dance, performing arts, and politics.You can visit Simon’s Web site, http://www.SimonRobinson.com

Christian Nagel Christian Nagel is an independent software architect and developer whooffers training and consulting on how to design and develop Microsoft NETsolutions He looks back to more than 15 years’ experience as a developerand software architect Christian started his computing career with PDP 11and VAX/VMS platforms, covering a variety of languages and platforms.Since the year 2000—when NET was just a technology preview—he hasbeen working with various NET technologies to build distributed solutions.With his profound knowledge of Microsoft technologies, he has also writtennumerous NET books; is certified as Microsoft Certified Trainer (MCT),Solution Developer (MCSD), and Systems Engineer (MCSE); and is theMicrosoft Regional Director for Austria Christian is a speaker at international conferences (TechED,DevDays, VCDC) and is the regional manager of INETA Europe (International NET User GroupAssociation) supporting NET user groups You can contact Christian via his Web site,

http://www.christiannagel.com

Jay Glynn Jay Glynn started writing software nearly 20 years ago, writing applicationsfor the PICK operating system using PICK basic Since then, he has createdsoftware using Paradox PAL and Object PAL, Delphi, VBA, Visual Basic, C,C++, Java, and of course C# He is currently a Project coordinator andArchitect for a large financial services company in Nashville, Tennessee,working on software for the TabletPC platform He can be

contacted at jlsglynn@hotmail.com

Morgan Skinner Morgan Skinner began his computing career at a tender age on a SinclairZX80 at school, where he was underwhelmed by some code a teacher hadwritten and so began programming in assembly language After gettinghooked on Z80 (which he believes is far better than those paltry 3 registers onthe 6502), he graduated through the school’s ZX81s to his own ZX Spectrum.Since then he’s used all sorts of languages and platforms, including VAXMacro Assembler, Pascal, Modula2, Smalltalk, X86 assembly language,PowerBuilder, C/C++, VB, and currently C# He’s been programming in.NET since the PDC release in 2000, and liked it so much, he joined Microsoft in 2001 He now works inPremier Support for Developers and spends most of his time assisting customers with C#.

You can reach Morgan at http://www.morganskinner.com

Karli Watson

Karli Watson is a freelance author and the technical director of 3form Ltd(http://www.3form.net) Despite starting out by studying nanoscalephysics, the lure of cold, hard cash proved too much and dragged Karli intothe world of computing He has since written numerous books on NET andrelated technologies, SQL, mobile computing, and a novel that has yet to seethe light of day (but that doesn’t have any computers in it) Karli is alsoknown for his multicolored clothing, is a snowboarding enthusiast, and stillwishes he had a cat

Bill Evjen Bill Evjen is an active proponent of the NET technologies and community-based learning initiatives for NET He has been actively involved with NETsince the first bits were released in 2000 and has since become president ofthe St Louis NET User Group (http://www.stlusergroups.org) Bill isalso the founder and executive director of the International NET ssociation(http://www.ineta.org), which represents more than 125,000 membersworldwide Based in St Louis, Missouri, USA, Bill is an acclaimed author

and speaker on ASP.NET and XML Web services He has written XML Web

Services for ASP.NET, Web Services Enhancements: Understanding the WSE for Enterprise Applications, Visual Basic NET Bible, and ASP.NET Professional Secrets (all published by Wiley) Bill is a Technical Director for Reuters, the

international news and financial services company He graduated from Western Washington University

in Bellingham, Washington, with a Russian language degree You can reach Bill at evjen@yahoo.com.Contributor

Allen Jones

Allen Jones has a career spanning 15 years that covers a broad range of IT disciplines, including prise management, solution and enterprise architecture, and project management But software develop-ment has always been Allen’s passion Allen has architected and developed Microsoft Windows–basedsolutions since 1990, including a variety of e-commerce, trading, and security systems

enter-Allen has co-authored four popular NET books including the C# Programmer's Cookbook (Microsoft Press) and Programming NET Security (O’Reilly), and he is actively involved in the development of

courseware for Microsoft Learning covering emerging NET technologies

Text Design & Composition

Wiley Indianapolis Composition Services

Introduction xxvii

The Relationship of C# to NET 4 The Common Language Runtime 4

A Closer Look at Intermediate Language 7

Creating NET Applications Using C# 21

More on Compiling C# Files 63

The C# Preprocessor Directives 70

readonly Fields 99

Operator Precedence 137

Comparing Objects for Equality 142

Memory Management under the Hood 187

Implementing IDisposable and a Destructor 196

Reflection 265

Summary 276

Chapter 11: Errors and Exceptions 277

Looking into Errors and Exception Handling 277

Summary 297

Working with Visual Studio NET 2003 301

Summary 337

Global Assembly Cache 366

Creating Shared Assemblies 369

Support for Security in the Framework 405

Managing Security Policy 419

Distributing Code Using Certificates 429

Chapter 16: Distributed Applications with NET Remoting 455

Contexts 460

Remote Objects, Clients, and Servers 462

Localization Example Using Visual Studio NET 527

Globalization and Localization with ASP.NET 539

A Custom Resource Reader 540

Part III: Windows Forms 571

Creating a Windows Form Application 574

Understanding Drawing Principles 624

Measuring Coordinates and Areas 632

Drawing Scrollable Windows 638

Drawing Shapes and Lines 650

Fonts and Font Families 657 Example: Enumerating Font Families 659 Editing a Text Document: The CapsEditor Sample 661

Using Database Connections 688

Commands 693

Fast Data Access: The Data Reader 701 Managing Data and Relationships: The DataSet Class 704

Persisting DataSet Changes 723

Using XPath and XSLT in NET 802

XML and ADO.NET 812

Serializing Objects in XML 825

Summary 836

The Architecture of Active Directory 838

Administration Tools for Active Directory 845

Searching for User Objects 864

Summary 869

ASP.NET Web Forms 875

ADO.NET and Data Binding 892

Application Configuration 906 Summary 907

Extending the Event-Booking Example 918

Exchanging Data Using SOAP Headers 924 Summary 929

Summary 962

Using a NET Component from a COM Client 985

Running Windows Forms Controls in Internet Explorer 997

Creating a Simple COM+ Application 1003

Managing the File System 1026

Moving, Copying, and Deleting Files 1035

Reading and Writing to Files 1039

Reading and Writing to the Registry 1054

Summary 1066

WebRequest and WebResponse Classes 1070

Displaying Output as an HTML Page 1074

What Is a Windows Service? 1091 Windows Services Architecture 1093

System.ServiceProcess Namespace 1095 Creating a Windows Service 1096

If we were to describe the C# language and its associated environment, the NET Framework, as themost important new technology for developers for many years, we would not be exaggerating .NET isdesigned to provide a new environment within which you can develop almost any application to run onWindows, while C# is a new programming language that has been designed specifically to work with.NET Using C# you can, for example, write a dynamic Web page, an XML Web service, a component of adistributed application, a database access component, or a classic Windows desktop application Thisbook covers the NET Framework 1.1, the second release of the framework, though most of this bookalso applies to NET Framework 1.0 If you are coding using version 1.0, then you might have to makesome changes, which we try to note throughout the book

Don’t be fooled by the NET label The NET bit in the name is there to emphasize Microsoft’s belief thatdistributed applications, in which the processing is distributed between client and server, are the wayforward, but C# is not just a language for writing Internet or network-aware applications It provides ameans for you to code up almost any type of software or component that you might need to write for theWindows platform Between them, C# and NET are set both to revolutionize the way that you writeprograms, and to make programming on Windows much easier than it has ever been

That’s quite a substantial claim, and it needs to be justified After all, we all know how quickly computertechnology changes Every year Microsoft brings out new software, programming tools, or versions ofWindows, with the claim that these will be hugely beneficial to developers So what’s different about.NET and C#?

The Significance of NET and C#

In order to understand the significance of NET, it is useful to remind ourselves of the nature of many ofthe Windows technologies that have appeared in the past ten years or so Although they may look quitedifferent on the surface, all of the Windows operating systems from Windows 3.1 (introduced in 1992)through Windows Server 2003 have the same familiar Windows API at their core As we’ve progressedthrough new versions of Windows, huge numbers of new functions have been added to the API, but thishas been a process of evolving and extending the API rather than replacing it

The same can be said for many of the technologies and frameworks that we’ve used to develop software

for Windows For example, COM (Component Object Model) originated as OLE (Object Linking and

Embedding) At the time, it was, to a large extent, simply a means by which different types of Officedocuments could be linked, so that for example you could place a small Excel spreadsheet in your Word

document From that it evolved into COM, DCOM (Distributed COM), and eventually COM+—a

sophisticated technology that formed the basis of the way almost all components communicated, as well

as implementing transactions, messaging services, and object pooling

Microsoft chose this evolutionary approach to software for the obvious reason that it is concerned aboutbackward compatibility Over the years a huge base of third-party software has been written forWindows, and Windows wouldn’t have enjoyed the success it has had if every time Microsoft intro-

While backward compatibility has been a crucial feature of Windows technologies and one of thestrengths of the Windows platform, it does have a big disadvantage Every time some technologyevolves and adds new features, it ends up a bit more complicated than it was before

It was clear that something had to change Microsoft couldn’t go on forever extending the same ment tools and languages, always making them more and more complex in order to satisfy the conflict-ing demands of keeping up with the newest hardware and maintaining backward compatibility withwhat was around when Windows first became popular in the early 1990s There comes a point whereyou have to start with a clean slate if you want a simple yet sophisticated set of languages, environ-ments, and developer tools, which make it easy for developers to write state-of-the-art software

develop-This fresh start is what C# and NET are all about Roughly speaking, NET is a new framework—a newAPI—for programming on the Windows platform Along with the NET Framework, C# is a new lan-guage that has been designed from scratch to work with NET, as well as to take advantage of all theprogress in developer environments and in our understanding of object-oriented programming princi-ples that have taken place over the past 20 years

Before we continue, we should make it clear that backward compatibility has not been lost in the cess Existing programs will continue to work, and NET was designed with the ability to work withexisting software Communication between software components on Windows presently almost entirelytakes place using COM Taking account of this, NET does have the ability to provide wrappers aroundexisting COM components so that NET components can talk to them

pro-It is true that you don’t need to learn C# in order to write code for NET Microsoft has extended C++,provided another new language called J#, and made substantial changes to Visual Basic to turn it intothe more powerful language Visual Basic NET, in order to allow code written in either of these lan-guages to target the NET environment These other languages, however, are hampered by the legacy ofhaving evolved over the years rather than having been written from the start with today’s technology

❑ Language Independence—with NET, all of the languages Visual Basic NET, C#, J#, and

man-aged C++ compile to a common Intermediate Language This means that languages are

inter-operable in a way that has not been seen before

❑ Better Support for Dynamic Web Pages—while ASP offered a lot of flexibility, it was also cient because of its use of interpreted scripting languages, and the lack of object-oriented designoften resulted in messy ASP code .NET offers an integrated support for Web pages, using a newtechnology—ASP.NET With ASP.NET, code in your pages is compiled, and may be written in a.NET-aware high-level language such as C#, J#, or Visual Basic NET

ineffi-❑ Efficient Data Access—a set of NET components, collectively known as ADO.NET, providesefficient access to relational databases and a variety of data sources Components are also avail-able to allow access to the file system, and to directories In particular, XML support is built into.NET, allowing you to manipulate data, which may be imported from or exported to non-Windows platforms

❑ Code Sharing—.NET has completely revamped the way that code is shared between

applica-tions, introducing the concept of the assembly, which replaces the traditional DLL Assemblies

have formal facilities for versioning, and different versions of assemblies can exist side by side

❑ Improved Security—each assembly can also contain built-in security information that can cate precisely who or what category of user or process is allowed to call which methods onwhich classes This gives you a very fine degree of control over how the assemblies that youdeploy can be used

indi-❑ Zero Impact Installation—there are two types of assembly: shared and private Shared blies are common libraries available to all software, while private assemblies are intended onlyfor use with particular software A private assembly is entirely self-contained, so the process ofinstalling it is simple There are no registry entries; the appropriate files are simply placed in theappropriate folder in the file system

assem-❑ Support for Web Services—.NET has fully integrated support for developing Web services aseasily as you’d develop any other type of application

❑ Visual Studio NET 2003—.NET comes with a developer environment, Visual Studio NET,which can cope equally well with C++, C#, J#, and Visual Basic NET, as well as with ASP.NETcode Visual Studio NET integrates all the best features of the respective language-specific envi-ronments of Visual Studio 6

❑ C#—C# is a new object-oriented language intended for use with NET

We will be looking more closely at the benefits of the NET architecture in Chapter 1

What’s New in the NET Framewor k 1.1The first version of the NET Framework (1.0) was released in 2002 to much enthusiasm The latest ver-sion, the NET Framework 1.1, was introduced in 2003 and is considered a minor release of the frame-work Even though this is considered a minor release of the framework, there are some prettyoutstanding new changes and additions to this new version and it definitely deserves some attention.With all the changes made to version 1.1 of the framework, Microsoft tried to ensure that there wereminimal breaking changes to code developed in using version 1.0 Even though the effort was there,

there are some breaking changes between the versions A lot of these breaking changes were made inorder to improve security You will find a comprehensive list of breaking changes on Microsoft’sGotDotNet Web site at http://www.gotdotnet.com.

The following details some of the changes that are new to the NET Framework 1.1 as well as new tions to Visual Studio NET 2003—the development environment for the NET Framework 1.1

addi-Mobility

When using the NET Framework 1.0 and Visual Studio NET 2002, to be able to build mobile tions you had to go out and download the Microsoft Mobile Internet Toolkit (MMIT) Now, with the.NET Framework 1.1 and Visual Studio NET 2003, this is built right in and therefore no separate down-load is required

applica-This is all quite evident when you create a new project using Visual Studio NET 2003 For instance,when you look at the list of available C# project types you can create, you will find ASP.NET MobileWeb Application and Smart Device Application You would use the ASP.NET Mobile Web Applicationproject type to build Web-based mobile applications (as the name describes) Building a Smart DeviceApplication allows you to create applications for the Pocket PC or any other Windows CE device Thethick-client applications built for a Windows CE device utilize the Compact Framework, a trimmed-down version of the NET Framework

Opening one of these mobile project types, you will then be presented with a list of available mobileserver controls in the Visual Studio NET Toolbox that you can then use to build your applications

New Data Providers

Another big area of change in the framework is to ADO.NET ADO.NET, the NET way of accessing andworking with data, now has two new data providers—one for ODBC and another for Oracle

An ODBC data provider was available when working with the NET Framework 1.0, but this required aseparate download Also, once downloaded, the namespace for this data provider was

Make sure that you create a staging server to completely test the upgrade of your

applications to the NET Framework 1.1 as opposed to just upgrading a live

application.

A New Language: Visual J#

When you install Visual Studio NET 2003, you will notice that a new language is available to you forbuilding NET applications—J# Prior to this, when using Visual Studio NET 2002, you were forced toinstall the language as a separate download

Visual J#, or simply J# (pronounced J-sharp), is the next version of the Visual J++ language You will find

that it is very similar to the Java language The hope with this language is that Java developers will find

it an easy transition to NET A J# developer will use the NET class libraries in place of the Java runtimelibraries

J# developers will have access to much of the same capabilities as a C# developer on the NET platform.Using J#, it is just as possible to build NET classes, Windows Forms applications, ASP.NET Web applica-tions, and XML Web services In addition, you can use J# in the same cross-language ways that you canuse other NET-compliant languages For instance, you can build a J# class and use this class in your C#application or vice versa

Also like the other languages, there is a built-in compiler for J# now in the NET Framework To find any

of the compilers, you will see them at C:\Windows\Microsoft.NET\Framework\v1.1.xxxx The C#compiler is csc.exe, the Visual Basic NET compiler is vbc.exe, and the J# compiler is vjc.exe

Side-by-Side Execution

Side-by-side execution is the ability to run multiple versions of an application on the same server wheredifferent application versions target different runtime versions This was always promised to us asdevelopers, but it was always hard to visualize as only one version of the framework was available.With the release of a second version of the framework (.NET Framework 1.1), we can actually see that it

is possible to have this capability Therefore, you can build new versions of your NET applications thattarget this latest NET Framework version release, but at the same time you can allow the older versions

of your application that target the NET Framework 1.0 to continue to work just as they always have

Support for Internet Protocol Version 6 (IPv6)

Presently, much of the Internet runs using IP version 4, also referred to as IPv4 IPv4 gives us IPaddresses such as 255.255.255.255 The NET Framework 1.1 now supports IPv6, which was created

in 1995 to address many of the problems that the world was facing with IPv4 Most of the problems dealwith the fact that by the world’s continual use of IPv4, we are rapidly running out of available IPaddresses

IPv6 is supported in the NET Framework 1.1 through the System.Netnamespace as well as inASP.NET and XML Web services

Visual Studio NET 2003 Enhancements

Along with the upgrade to the NET Framework, Visual Studio NET itself has also undergone anupgrade You will notice that there are some new graphics on the Start Page available and that things onthis page are organized a little differently Besides that, the biggest thing to notice with this new IDE isthat once installed, it does not simply upgrade Visual Studio NET 2002 to Visual Studio NET 2003

Instead, it installs a completely new version of the IDE, and if you already have VS.NET 2002 on yourmachine, then you will have two complete VS.NET IDEs on your box The reason for this is so that if youwant to build and work with applications that target the NET Framework version 1.0, then you will useVS.NET 2002, and if you want to build and work with applications that target the NET Framework ver-sion 1.1 then you will use VS.NET 2003.

You should also be aware that when you open a project that was built using VS.NET 2002, you will beasked if you want to upgrade the project to be a VS.NET 2003 project Doing this will then cause the pro-ject to be re-targeted at the NET Framework 1.1 Be careful about doing this as it is an irreversible process.Besides these big changes, you will find that VS.NET 2003 is a better IDE with smarter Intellisense andcode completion This version of the IDE is the IDE that is used throughout the examples of this book

Where C# F its In

In one sense, C# can be seen as being the same thing to programming languages as NET is to theWindows environment Just as Microsoft has been adding more and more features to Windows and theWindows API over the past decade, Visual Basic and C++ have undergone expansion Although VisualBasic and C++ have ended up as hugely powerful languages as a result of this, both languages also suf-fer from problems due to the legacies of how they have evolved

In the case of Visual Basic 6 and earlier, the main strength of the language was the fact that it was simple

to understand and didn’t make many programming tasks easy, largely hiding the details of the

Windows API and the COM component infrastructure from the developer The downside to this wasthat Visual Basic was never truly object-oriented, so that large applications quickly become disorganizedand hard to maintain As well as this, because Visual Basic’s syntax was inherited from early versions ofBASIC (which, in turn, was designed to be intuitively simple for beginning programmers to understand,rather than to write large commercial applications), it didn’t really lend itself to well-structured orobject-oriented programs

C++, on the other hand, has its roots in the ANSI C++ language definition It isn’t completely compliant for the simple reason that Microsoft first wrote its C++ compiler before the ANSI definitionhad become official, but it comes close Unfortunately, this has led to two problems First, ANSI C++ hasits roots in a decade-old state of technology, and this shows up in a lack of support for modern concepts(such as Unicode strings and generating XML documentation), and in some archaic syntax structuresdesigned for the compilers of yesteryear (such as the separation of declaration from definition of mem-ber functions) Second, Microsoft has been simultaneously trying to evolve C++ into a language that isdesigned for high-performance tasks on Windows, and in order to achieve that they’ve been forced toadd a huge number of Microsoft-specific keywords as well as various libraries to the language Theresult is that on Windows, the language has become a complete mess Just ask C++ developers howmany definitions for a string they can think of: char*, LPTSTR, string, CString(MFC version),

ANSI-CString(WTL version), wchar_t*, OLECHAR*, and so on

Now enter NET—a completely new environment that is going to involve new extensions to both guages Microsoft has gotten around this by adding yet more Microsoft-specific keywords to C++, and

lan-by completely revamping Visual Basic into Visual Basic NET, a language that retains some of the basic

VB syntax but that is so different in design that we can consider it to be, for all practical purposes, a newlanguage

It’s in this context that Microsoft has decided to give developers an alternative—a language designedspecifically for NET, and designed with a clean slate Visual C# NET is the result Officially, Microsoftdescribes C# as a “simple, modern, object-oriented, and type-safe programming language derived from

C and C++.” Most independent observers would probably change that to “derived from C, C++, andJava.” Such descriptions are technically accurate but do little to convey the beauty or elegance of the lan-guage Syntactically, C# is very similar to both C++ and Java, to such an extent that many keywords arethe same, and C# also shares the same block structure with braces ({}) to mark blocks of code, and semi-colons to separate statements The first impression of a piece of C# code is that it looks quite like C++ orJava code Behind that initial similarity, however, C# is a lot easier to learn than C++, and of comparabledifficulty to Java Its design is more in tune with modern developer tools than both of those other lan-guages, and it has been designed to give us, simultaneously, the ease of use of Visual Basic, and the high-performance, low-level memory access of C++ if required Some of the features of C# are:

❑ Full support for classes and object-oriented programming, including both interface and mentation inheritance, virtual functions, and operator overloading

imple-❑ A consistent and well-defined set of basic types

❑ Built-in support for automatic generation of XML documentation

❑ Automatic cleanup of dynamically allocated memory

❑ The facility to mark classes or methods with user-defined attributes This can be useful for umentation and can have some effects on compilation (for example, marking methods to becompiled only in debug builds)

doc-❑ Full access to the NET base class library, as well as easy access to the Windows API (if youreally need it, which won’t be all that often)

❑ Pointers and direct memory access are available if required, but the language has been designed

in such a way that you can work without them in almost all cases

❑ Support for properties and events in the style of Visual Basic

❑ Just by changing the compiler options, you can compile either to an executable or to a library of.NET components that can be called up by other code in the same way as ActiveX controls(COM components)

❑ C# can be used to write ASP.NET dynamic Web pages and XML Web services

Most of the above statements, it should be pointed out, do also apply to Visual Basic NET and ManagedC++ The fact that C# is designed from the start to work with NET, however, means that its support forthe features of NET is both more complete, and offered within the context of a more suitable syntax thanfor those other languages While the C# language itself is very similar to Java, there are some improve-ments: in particular, Java is not designed to work with the NET environment

Before we leave the subject, we should point out a couple of limitations of C# The one area the language

is not designed for is time-critical or extremely high performance code—the kind where you really areworried about whether a loop takes 1,000 or 1,050 machine cycles to run through, and you need to clean

up your resources the millisecond they are no longer needed C++ is likely to continue to reign supremeamong low-level languages in this area C# lacks certain key facilities needed for extremely high perfor-mance apps, including the ability to specify inline functions and destructors that are guaranteed to run

at particular points in the code However, the proportions of applications that fall into this category arevery low

What You Need to Write and Run C# Code

.NET will run on Windows 98, 2000, XP, and 2003 In order to write code using NET, you will need toinstall the NET SDK unless you are using Windows Server 2003, which comes with the NET

Framework 1.0 and 1.1 already installed Unless you are intending to write your C# code using a texteditor or some other third party developer environment, you will almost certainly also want VisualStudio NET 2003 The full SDK isn’t needed to run managed code, but the NET runtime is needed Youmay find you need to distribute the NET runtime with your code for the benefit of those clients who donot have it already installed

What This Book Covers

In this book, we start by reviewing the overall architecture of NET in the next chapter in order to give usthe background we need to be able to write managed code After that the book is divided into a number

of sections that cover both the C# language and its application in a variety of areas

Part I: The C# Language

This section gives us a good grounding in the C# language itself This section doesn’t presume edge of any particular language, although it does assume you are an experienced programmer We start

knowl-by looking at C#’s basic syntax and datatypes, and then discuss the object-oriented features of C# beforemoving on to look at more advanced C# programming topics

Part II: The NET Environment

In this section, we look at the principles of programming in the NET environment In particular, we look

at Visual Studio NET, security, threading deployment of NET applications, and how to generate yourown libraries as assemblies

Part III: Windows Forms

This section focuses on building classic Windows applications, which are called Windows Forms in.NET Windows Forms are the thick-client version of applications, and using NET to build these types ofapplications is a quick and easy way of accomplishing this task In addition to looking at WindowsForms, we will take a look at GDI+, which is the technology we will use for building applications thatinclude advanced graphics

Part IV: Data

Here we look at accessing databases with ADO.NET, and at interacting with directories and ActiveDirectory We also extensively cover support in NET for XML and on the Windows operating system side

Part V: Web Programming

In this section, we cover writing components that will run on Web sites, serving up Web pages This ers both ASP.NET and the writing of XML Web services

cov-Part VI: Interop

Backward compatibility with COM is an important part of NET Not only that, but COM+ is not strictlylegacy—it will still be responsible for transactions, object pooling, and message queuing In this sectionwe’ll look at the support NET offers for working with COM and COM+, as well as discussing how towrite C# code that interacts with these technologies

Part VII: Windows Base Services

This section, the concluding part of the main body of the book, covers accessing the file and registry,accessing the Internet through your applications, and working with Windows Services

Part VIII: Appendices (Web Site Only)

This section includes several appendices detailing the principles of object-oriented programming as well

as programming language–specific information about C# These appendices are available as PDFs on theWeb site accompanying this book (http://www.wrox.com)

Conventions

We have used a number of different styles of text and layout in the book to help differentiate betweenthe different kinds of information Here are examples of the styles we use and an explanation of whatthey mean:

Bullets appear indented, with each new bullet marked as follows:

❑ Important Wordsare in a bold type font

❑ Words that appear on the screen in menus like the File or Window are in a similar font to theone that you see on screen

❑ Keys that you press on the keyboard, like Ctrl and Enter, are in italics.

Code appears in a number of different ways If it’s a word that we’re talking about in the text—for ple, when discussing the if elseloop—it’s in this font If it’s a block of code that you can type in

exam-as a program and run, then it’s also in a gray box:

public static void Main(){

AFunc(1,2,”abc”);

}

Sometimes you’ll see code in a mixture of styles, like this:

// If we haven’t reached the end, return true, otherwise// set the position to invalid, and return false

pos++;

if (pos < 4)return true;

else {pos = -1;

return false;

}

The code with a white background is code we’ve already looked at and that we don’t wish to examinefurther

Advice, hints, and background information come in an italicized, indented font like this.

We demonstrate the syntactical usage of methods, properties (and so on) using the following format:

Regsvcs BookDistributor.dll [COM+AppName] [TypeLibrary.tbl]

Here, italicized parts indicate object references, variables, or parameter values to be inserted; the squarebraces indicate optional parameters

Source Code

As you work through the examples in this book, you may choose either to type in all the code manually

or to use the source code files that accompany the book All of the source code used in this book is able for download at http://www.wrox.com Once at the site, simply locate the book’s title (either byusing the Search box or by using one of the title lists) and click the Download Code link on the book’sdetail page to obtain all the source code for the book

avail-Because many books have similar titles, you may find it easiest to search by ISBN; this book’s ISBN is 0-7645-5759-9.

Once you download the code, just decompress it with your favorite compression tool Alternately,you can go to the main Wrox code download page at http://www.wrox.com/dynamic/books/download.aspxto see the code available for this book and all other Wrox books

Errata

We make every effort to ensure that there are no errors in the text or in the code However, no one is fect, and mistakes do occur If you find an error in one of our books, like a spelling mistake or faultypiece of code, we would be very grateful for your feedback By sending in errata you may save anotherreader hours of frustration, and at the same time you will be helping us provide even higher qualityinformation

per-Important pieces of information come in boxes like this.

To find the errata page for this book, go to http://www.wrox.comand locate the title using the Searchbox or one of the title lists Then, on the book details page, click the Book Errata link On this page youcan view all errata that have been submitted for this book and posted by Wrox editors A complete booklist including links to each book’s errata is also available at http://www.wrox.com/misc-pages/booklist.shtml.

If you don’t spot “your” error already on the Book Errata page, go to http://www.wrox.com/contact/techsupport.shtmland complete the form there to send us the error you have found We’ll check theinformation and, if appropriate, post a message to the book’s errata page and fix the problem in subse-quent editions of the book

p2p.wrox.comFor author and peer discussion, join the P2P forums at p2p.wrox.com The forums are a Web-based sys-tem for you to post messages relating to Wrox books and related technologies and to interact with otherreaders and technology users The forums offer a subscription feature to e-mail you topics of interest ofyour choosing when new posts are made to the forums Wrox authors, editors, other industry experts,and your fellow readers are present on these forums

At http://p2p.wrox.comyou will find a number of different forums that will help you not only asyou read this book, but also as you develop your own applications To join the forums, just follow these steps:

1. Go to p2p.wrox.comand click the Register link

2. Read the terms of use and click Agree.

3. Supply the required information to join as well as any optional information you wish to provideand click Submit

You will receive an e-mail with information describing how to verify your account and complete thejoining process

You can read messages in the forums without joining P2P, but you must join in order to post your own messages.

Once you join, you can post new messages and respond to other users’ posts You can read messages atany time on the Web If you would like to have new messages from a particular forum e-mailed to you,click the Subscribe to this Forum icon by the forum name in the forum listing

For more information about how to use the Wrox P2P, be sure to read the P2P FAQs for answers to tions about how the forum software works as well as many common questions specific to P2P and Wroxbooks To read the FAQs, click the FAQ link on any P2P page