The .NET SolutionC# and the .NET Platform, Second Edition

So much for the brief history lesson. The bottom line is that life as a Windows programmer has been

Apress © 2003 (1200 pages)

tough. The .NET Framework is a rather radical and brute-force approach to making our lives easier. The

This comprehensive text starts with a brief overview of the

solution proposedC#bylanguage.NET is "Changeand then quicklyeverythingmovesfromto herek y technicalon out" (sorry,and you can't blame the messenger for the message)architectural. As you will iseesuesduringfor .NETthe dremaindervelopers.of this book, the .NET Framework is a completely new model for building systems on the Windows family of operating systems, and additional (nonMicrosoft) operating systems now and in the future. To set the stage, here is a quick rundown of some

Table of Contents

core features provided courtesy of .NET:

C# and the .NET Platform, Second Edition

Full interoperability with existing Win32 code. This is (of course) a good thing. Existing COM binaries

Introduction

can commingle (i.e., interop) with newer .NET binaries and vice versa. Also, PInvoke (Platform

Part One - Introducing C# and the .NET Platform

Invocation) allows you to invoke invoke raw C-based functions (such as the Win32 API) from

Chapter 1 - The Philosophy of .NET

managed code.

Chapter 2 - Building C# Applications

Part Two - The C# Programming Language

Complete and total language integration. Unlike classic COM, .NET supports cross-language

Chapter 3 - C# Language Fundamentals

inheritance, cross-language exception handling, and crosslanguage debugging.

Chapter 4 - Object-Oriented Programming with C#

ChapterAcommon5 - ExceptionsruntimeandengineObjectsharedLifetimeby all .NET-aware languages. One aspect of this engine is a well-

Chapterdefined6 - Interfacesset of typesandthatCollectionseach .NET-aware language "understands."

Chapter 7 - Callback Interfaces, Delegates, and Events

Abase class library that provides shelter from the complexities of raw API calls, and offers a

Chapter 8 - Advanced C# Type Construction Techniques

consistent object model used by all .NET-aware languages.

Part Three - Programming with .NET Assemblies

Chapter 9 - Understanding .NET Assemblies

No more COM plumbing! IClassFactory, IUnknown, IDispatch, IDL code, and the evil VARIANT-

Chapter 10 - Processes, AppDomains, Contexts, and Threads

compliant data types (BSTR, SAFEARRAY, and so forth) have no place in a native .NET binary.

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming

Part FourAtruly- Leveragingsimplified deploymentthe .NET Librariesmodel. Under .NET, there is no need to register a binary unit into the

system registry. Furthermore, the .NET runtime allows multiple versions of the same *.dll to exist in

Chapter 12 - Object Serialization and the . Remoting Layer

harmony on a single machine (using an approach termed "side-by-side execution").

Chapter 13 - Building a Better Window (Introducing Windows Forms) Chapter 14 - A Better Painting Framework (GDI+)

Chapter 15 - Programming with Windows Forms Controls

Chapter 16 - The System.IO Namespace

Chapter 17 - Data Access with ADO.NET

Part Five - Web Applications and XML Web Services

Chapter 18 - ASP.NET Web Pages and Web Controls

Chapter 19 - ASP.NET Web Applications

Chapter 20 - XML Web Services

Index

List of Figures

List of Tables

The BuildingC# Blocksand the .NETofPlatform,the .NETSecondPlatformEditi n (CLR, CTS, and CLS)

Now that you have been given a peek into some of the benefits provided by .NET, let's preview three key

Apress © 2003 (1200 pages)

(and interrelated) entities that make it all possible: the CLR, CTS, and CLS. From a programmer's point of

This comprehensive text starts with a brief overview of the

view, .NET can beC#simplylanguageunderstoodand thenasquicklya newmovesruntimeto keyenvironmenttechnical andand a common base class library. The runtime layerarchitectuis properlyal referredissues forto.NETas thed veloperscommon. language runtime, or CLR. The primary role of the CLR is to locate, load, and manage .NET types on your behalf. The CLR also takes care of a number of low-level details such as automatic memory management, language integration, and ensuring type

Table of Contents safety.

C# and the .NET Platform, Second Edition

Another building block of the .NET platform is the Common Type System, or CTS. The CTS fully

Introduction

describes all possible data types and programming constructs supported by the runtime, specifies how

Part One - Introducing C# and the .NET Platform

these entities can interact with each other and details how they are represented in the .NET metadata

Chapter 1 - The Philosophy of .NET

format (more information on "metadata" later in this chapter).

Chapter 2 - Building C# Applications

Part Two - The C# Programming Language

Understand that a given .NET-aware language might not support each and every entity defined by the

Chapter 3 - C# Language Fundamentals

CTS. The Common Language Specification (CLS) is a set of rules that define a subset of common types

Chapter 4 - Object-Oriented Programming with C#

and programming constructs that all .NET programming languages can agree on. Thus, if you build .NET

Chapter 5 - Exceptions and Object Lifetime

types that only expose CLS-compliant features, you can rest assured that all .NET-aware languages could

Chapter 6 - Interfaces and Collections

make use of your types. Conversely, if you make use of a data type or programming construct that is

Chapter 7 - Callback Interfaces, Delegates, and Events

outside of the CLS, you cannot guarantee that every .NET programming language can interact with your

Chapterbinary code8 - Advlibrarynced. C# Type Construction Techniques

Part Three - Programming with .NET Assemblies

Chapter 9 - Understanding .NET Assemblies

Chapter 10 - Processes, AppDomains, Contexts, and Threads

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming

Part Four - Leveraging the .NET Libraries

Chapter 12 - Object Serialization and the .NET Remoting Layer

Chapter 13 - Building a Better Window (Introducing Windows Forms)

Chapter 14 - A Better Painting Framework (GDI+)

Chapter 15 - Programming with Windows Forms Controls

Chapter 16 - The System.IO Namespace

Chapter 17 - Data Access with ADO.NET

Part Five - Web Applications and XML Web Services

Chapter 18 - ASP.NET Web Pages and Web Controls

Chapter 19 - ASP.NET Web Applications

Chapter 20 - XML Web Services

Index

List of Figures

List of Tables

The Role ofC#theand.NETthe .NETBasePlatform,ClassSecondLibrariesEdition

In addition to the CLR and CTS/CLS specifications, the .NET platform provides a base class library that is

Apress © 2003 (1200 pages)

available to all .NET programming languages. Not only does this base class library encapsulate various

This comprehensive text starts with a brief overview of the

primitives such asC#threads,languagefileandIO,thengraphicalquicklyrenderingmoves toandkeyinteractiontechnical andwith various hardware devices, but it also provides supportarchitecturalfor a numberissu s offorservices.NET devrequiredlopers. by most real-world applications.

For example, the base class libraries define types that facilitate database manipulation, XML integration,

Tableprogrammaticof Contentssecurity, and the construction of Web-enabled (as well as traditional desktop and console- C#based)and thefront.NETendsPlatform,. From Sea conceptuald Editionpoint of view, you can visualize the relationship between the .NET

runtime layer and the corresponding base class library as shown in Figure 1-1.

Introduction

Part One - Introducing C# and the .NET Platform

Chapter

Chapter

Part

Chapter

Chapter

Chapter

Chapter

Chapter

Chapter

Part

Chapter 9 - Understanding .NET Assemblies

Figure 1-1: The CLR, CTS, CLS base class library relationship

Chapter 10 - Processes, AppDomains, Contexts, and Threads

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming

Part Four - Leveraging the .NET Libraries

Chapter 12 - Object Serialization and the .NET Remoting Layer

Chapter 13 - Building a Better Window (Introducing Windows Forms)

Chapter 14 - A Better Painting Framework (GDI+)

Chapter 15 - Programming with Windows Forms Controls

Chapter 16 - The System.IO Namespace

Chapter 17 - Data Access with ADO.NET

Part Five - Web Applications and XML Web Services

Chapter 18 - ASP.NET Web Pages and Web Controls

Chapter 19 - ASP.NET Web Applications

Chapter 20 - XML Web Services

Index

List of Figures

List of Tables

a new programming language (C#) specifically for this new platform. C# is a programming language that

This comprehensive text starts with a brief overview of the

looksvery similarC#(butlanotguageidentical)and thento thequicklysyntaxmovesof Javato key. Fortechnicalexample,andlike Java, a C# class definition is contained within architecturalsingle-sourceissuescodeforfile.NET(*.cs)developratherrsthan. the C++-centric view of splitting a class definition into discrete header (*.h) and implementation (*.cpp) files. However, to call C# a Java rip-off is inaccurate. Both C# and Java are based on the syntactical constructs of C++. Just as Java is in many

Table of Contents

ways a cleaned-up version of C++, C# can be viewed as a cleaned-up version of Java—after all, they are

C# aind the .NET Platform, Second Edition all the same family of languages.

Introduction

The truth of the matter is that many of C#'s syntactic constructs are modeled after various aspects of

Part One - Introducing C# and the .NET Platform

Visual Basic and C++ itself. For example, like Visual Basic, C# supports the notion of formal class

Chapter 1 - The Philosophy of .NET

properties as well the declaration of methods that take a varying number of arguments (via parameter

Chapter 2 - Building C# Applications

arrays). Like C++, C# allows you to overload operators on your custom types, as well as create structures

Part Two - The C# Programming Language

(value types) and enumerations (as you may know, Java lacks all of these features).

Chapter 3 - C# Language Fundamentals

Chapter 4 - Object-Oriented Programming with C#

Given that C# is a hybrid of numerous languages, the result is a product that is as syntactically clean (if not

Chapter 5 - Exceptions and Object Lifetime

cleaner) than Java, just about as simple as Visual Basic 6.0, and provides just about as much power and

Chapter 6 - Interfaces and Collections

flexibility as C++ (without the associated ugly bits). In a nutshell, the C# languages offers the following

Chapter 7 - Callback Interfaces, Delegates, and Events

features (many of which are shared by other .NET-aware programming languages):

Chapter 8 - Advanced C# Type Construction Techniques

No pointers required! C# programs typically have no need for direct pointer manipulation (although

Part Three - Programming with .NET Assemblies

you are free to drop down to that level if you desire, as seen in Chapter 8).

Chapter 9 - Understanding .NET Assemblies

Chapter 10 - Processes, AppDomains, Contexts, and Threads

Automatic memory management. Given this, C# does not support a "delete" keyword.

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming

Part FourFormal- Leveragingsyntactic theconstructs.NET Librariesfor enumerations, structures, and class properties.

Chapter 12 - Object Serialization and the .NET Remoting Layer

The C++-like ability to overload operators for a custom type, without the complexity (i.e., making sure

Chapter 13 - Building a Better Window (Introducing Windows Forms)

to "return *this to allow chaining" is not your problem).

Chapter 14 - A Better Painting Framework (GDI+)

Chapter 15 - Programming with Windows Forms Controls

Full support for interface-based programming techniques. However, unlike classic COM, the interface

Chapter 16 - The System.IO Namespace

isnot the only way to manipulate types between binaries. .NET supports true object references that

Chapter 17 - Data Access with ADO.NET

can be passed between boundaries (by reference or by value).

Part Five - Web Applications and XML Web Services

ChapterFull18support- ASP.NETfor aspectWeb Pages-basedandprogrammingWeb Controlstechniques via attributes. This brand of development Chapterallows19 -youASPto.NETassignWebcharacteristicsApplications to types and their members (much like COM IDL) to further qualify

the behavior of a given entity.

Chapter 20 - XML Web Services

Index

Perhaps the most important point to understand about the C# language shipped with the .NET platform is

List of Figures

that it can only produce code that can execute within the .NET runtime (you could never use C# to build a

List of Tables

classic COM server or a traditional Win32 API application). Officially speaking, the term used to describe the code targeting the .NET runtime is managed code. The binary unit that contains the managed code is termed an assembly (more details in just a bit).

keywords as possible. Others enjoy a language that offers more "human-readable" syntactic tokens (such

C# and the .NET Platform, Second Edition

as VB .NET). Still others may want to leverage their mainframe skills while moving to the .NET platform

by Andrew Troelsen ISBN:1590590554

(via COBOL .NET).

Apress © 2003 (1200 pages)

Now, be honest: IfThisMicrosoftomprehensivewere to textbuildstartsa singlewith"official"a brief overview.NET languageof the that was derived from the BASIC family of languages,C# lan uagecandyouthenreallyquicklysaymovesall programmersto key t chnicalwouldandbe happy with this choice? Or, if the

architectural issues for .NET developers.

single official managed language was based on C syntax, imagine all the folks out there who would ignore

.NET altogether. Because the .NET runtime could care less where a block of managed code originated,

.NET programmers can stay true to their syntactic preferences, and share the compiled assemblies

Table of Contents

among teammates, departments, and external organizations (regardless of which .NET language others

C# and the .NET Platform, Second Edition

choose to use).

Introduction

PartAnotherOne -excellentIntroducingbyproductC# and oftheintegrating.NET Platformvarious .NET languages into a single unified software solution is

Chapterthe simple1 -factThethatPhilosoall programminghy of .NET languages have their own sets of strengths and weaknesses. For Chapterexample,2 some- BuildingprogrammingC# Applicationslanguages offer excellent intrinsic support for advanced mathematical Paprocessingt Two - The. OthersC# Programmingoffer superiorLanguagesupport for graphical rendering, financial calculations, logical

calculations, interaction with mainframe computers and so forth. When you take the strengths of a

Chapter 3 - C# Language Fundamentals

particular programming language and then incorporate the benefits provided by the .NET platform,

Chapter 4 - Object-Oriented Programming with C#

everybody wins.

Chapter 5 - Exceptions and Object Lifetime

Chapter 6 - Interfaces and Collections

Of course, in reality the chances are quite good that you will spend much of your time building software

Chapter 7 - Callback Interfaces, Delegates, and Events

using your .NET language of choice (which is great!) However, as you may be expecting, once you learn

Chapter 8 - Advanced C# Type Construction Techniques

the syntax of one .NET language, it is very easy to master another. This is also quite beneficial, especially

Part Four - Leveraging the .NET Libraries

Chapter 12 - Object Serialization and the .NET Remoting Layer

Chapter 13 - Building a Better Window (Introducing Windows Forms)

Chapter 14 - A Better Painting Framework (GDI+)

Chapter 15 - Programming with Windows Forms Controls

Chapter 16 - The System.IO Namespace

Chapter 17 - Data Access with ADO.NET

Part Five - Web Applications and XML Web Services

Chapter 18 - ASP.NET Web Pages and Web Controls

Chapter 19 - ASP.NET Web Applications

Chapter 20 - XML Web Services

Index

List of Figures

List of Tables

An OverviewC#ofand.NETthe .NETBinariesPlatform, Second(aka EditionAssemblies)

Regardless of which .NET language you choose to program with, understand that despite the fact that

Apress © 2003 (1200 pages)

.NET binaries take the same file extension as classic COM binaries (*.dll or *.exe), they have absolutely no

This comprehensive text starts with a brief overview of the

internal similaritiesC#. Forlanguageexample,and *then.dll .NETquicklybinariesmovesdoto notkey exporttechnicalmethodsand to facilitate communications with the classic COMarchitecturalruntimeissu(givens forthat.NET.NETdevelopersis not COM). . Furthermore, .NET binaries are not described using IDL and are not registered into the system registry. Perhaps most important, unlike classic COM servers, .NET binaries do not contain platform-specific instructions, but rather platform-agnostic

Table of Contents

"intermediate language" (IL). Conceptually, Figure 1-2 shows the big picture of the story thus far.

C# and the .NET Platform, Second Edition

Introduction

Part

Chapter

Chapter

Part

Chapter

Chapter

Chapter

Chapter

Chapter

Chapter 8 - Advanced C# Type Construction Techniques

Figure 1-2: All .NET-aware compilers emit IL instructions and metadata.

Part Three - Programming with .NET Assemblies

Chapter 9 - Understanding .NET Assemblies

Note There is one point to be made regarding the acronym "IL." During the development of .NET, the

Chapter 10 - Processes, AppDomains, Contexts, and Threads

official term for "IL" was Microsoft intermediate language (MSIL). However with the final release

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming

of .NET, the (new) official term is common intermediate language (CIL). Thus, as you read the

Part Four - Leveraging the .NET Libraries

.NET literature (including the first edition of this text), understand that IL, MSIL and CIL are all

Chapter 12 - Object Serialization and the .NET Remoting Layer

describing the same exact entity. In keeping with the current terminology, I will use the term CIL

Chapter 13 - Building a Better Window (Introducing Windows Forms)

throughout this text from here on out.

Chapter 14 - A Better Painting Framework (GDI+)

Chapter 15 - Programming with Windows Forms Controls

When a *.dll or *.exe has been created using a .NET-aware compiler, the resulting module is bundled into

Chapter 16 - The Systexamine.IO Namespace

an "assembly." You numerous details of .NET assemblies in Chapter 9. However to facilitate the Chapterdiscussion17 -ofDatatheAccess.NET runtimewith ADOenvironment,.NET you do need to examine some basic properties of this new

Partfile Fiveformat- Web. Applications and XML Web Services

Chapter 18 - ASP.NET Web Pages and Web Controls

As mentioned, an assembly contains CIL code, which is conceptually similar to Java byte code in that it is

Chapter 19 - ASP.NET Web Applications

not compiled to platform-specific instructions until absolutely necessary. Typically "absolutely necessary"

Chapter 20 - XML Web Services

is the point at which a block of CIL instructions (such as a method implementation) are referenced for use

Index

by the .NET runtime engine.

List of Figures

List of Tables

In addition to CIL instructions, assemblies also contain metadata that describes in vivid detail the characteristics of every "type" living within the binary. For example, if you have a class named Car contained within a given assembly, the type metadata describes details such as Car's base class, which interfaces are implemented by Car (if any), as well as a full description of each member supported by the Car type.

In many respects, .NET metadata is a dramatic improvement to classic COM type information. As you may already know, classic COM binaries are typically described using an associated type library (which is little more than a binary version of IDL code). The problems with COM type information are that it is not guaranteed to be present, and the fact that IDL code has no way to catalog externally referenced servers that are required for the correct operation of the contained coclasses (a.k.a. 'COM class'). In contrast,

.NET metadata is always present and is automatically generated by a given .NET-aware compiler.

Finally, in addition to CIL and type metadata, assemblies themselves are also described using metadata, which is officially termed a manifest. The manifest contains information about the current version of the assembly, culture information (used for localizing string and image resources), and a list of all externally

referenced assemblies that are required for proper execution. You examine various tools that can be used

C# and the .NET Platform, Second Edition

to examine an assembly's underlying CIL, type metadata and manifest information later in this chapter.

Single File and Multifile Assemblies

This comprehensive text starts with a brief overview of the

C# language and then quickly moves to key technical and

In a great number of cases, there is a simple one-to-one correspondence between a .NET assembly and architectural issues for .NET developers.

the underlying *.dll or *.exe binary. Thus, if you are building a .NET *.dll, it is safe to consider that the binary and the assembly are one and the same. Likewise, if you are building a .NET *.exe desktop Tableapplication,of C tentsthe *.exe can simply be referred to as the assembly itself. As seen in Chapter 9 however, this

is not completely accurate. Technically speaking, if an assembly is composed of a single *.dll or *.exe

C# and the .NET Platform, Second Edition

module, you have a "single file assembly." Single file assemblies contain all the necessary CIL, metadata

Introduction

and associated manifest in an autonomous, single, well-defined package.

Part One - Introducing C# and the .NET Platform

Chapter 1 - The Philosophy of .NET

Multifile assemblies, on the other hand, are composed of numerous .NET binaries, each of which is

Chapter 2 - Building C# Applications

termed a module. When building a multifile assembly, one of these modules (termed the primary module)

Part Two - The C# Programming Language

must contain the assembly manifest (and possibly CIL instructions and metadata for various types). The

Chapter 3 - C# Language Fundamentals

other related modules contain a module level manifest, CIL and type metadata. As you might suspect, the

Chapter 4 - Object-Oriented Programming with C#

primary module documents the set of required secondary modules within the assembly manifest.

Chapter 5 - Exceptions and Object Lifetime

ChapterSo, why6 would- Interfacesyou chooseand Ctollectionscreate a multifile assembly? When you partition an assembly into discrete

modules, you end up with a more flexible deployment option. For example, if a user is referencing a

Chapter 7 - Callback Interfaces, Delegates, and Events

remote assembly that needs to be downloaded onto his or her machine, the runtime will only download

Chapter 8 - Advanced C# Type Construction Techniques

the required modules. Therefore, you are free to construct your assembly in such a way that less

Part Three - Programming with .NET Assemblies

frequently required types (such as a type named HardDriveReformatter) are kept in a separate stand-

Chapter 9 - Understanding .NET Assemblies

alone module.

Chapter 10 - Processes, AppDomains, Contexts, and Threads

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming

In contrast, if all your types were placed in a single file assembly, the end user may end up downloading a

Part Four - Leveraging the .NET Libraries

large chunk of data that is not really needed (which is obviously a waste of time). Thus, as you can see, an

Chapter 12 - Object Serialization and the .NET Remoting Layer

assembly is really a logical grouping of one or more related modules that are intended to be deployed and

Chapter 13 - Building a Better Window (Introducing Windows Forms) versioned as a single unit.

Chapter 14 - A Better Painting Framework (GDI+)

Chapter 15 - Programming with Windows Forms Controls

Chapter 16 - The System.IO Namespace

Chapter 17 - Data Access with ADO.NET

Part Five - Web Applications and XML Web Services

Chapter 18 - ASP.NET Web Pages and Web Controls

Chapter 19 - ASP.NET Web Applications

Chapter 20 - XML Web Services

Index

List of Figures

List of Tables

The Role ofC#theandCommonthe .NET Platform,IntermediateSecond EditionLanguage

Now that you have a better feel for .NET assemblies, let's examine the role of the common intermediate

Apress © 2003 (1200 pages)

language (CIL) in a bit more detail. CIL is a language that sits above any particular platform-specific

This comprehensive text starts with a brief overview of the

instruction set. RegardlessC# languageof whichand then.NETquickly-awaremoveslanguageto keyyoutechnicalchooseand(C#, Visual Basic .NET, Eiffel

.NET, and so forth),architthecturalassociatedissues compilerf r .NET developersemits CIL.instructions. For example, the following C# namespace definition models a trivial calculator (which is only capable of returning the sum of 10 and 84...). Don't concern yourself with the exact syntax for the time being, but do notice the signature of the

Table of Contents

Add() method:

C# and the .NET Platform, Second Edition

Introduction

// We will examine namespaces later in the chapter...

Part One - Introducing C# and the .NET Platform

using System;

Chapter 1 - The Philosophy of .NET

Chapter 2 - Building C# Applications

namespace Calculator

Part Two - The C# Programming Language

{

Chapter 3 - C# Language Fundamentals

// This class contains the app's entry point.

Chapter 4 - Object-Oriented Programming with C# public class CalcApp

Chapter {5 - Exceptions and Object Lifetime

Chapter 6 - Interfacespublic staticand Collectivonsid Main()

Chapter 7 - Callback{ Interfaces, Delegates, and Events

Calc c = new Calc();

Chapter 8 - Advanced C# Type Construction Techniques

int ans = c.Add(10, 84);

Part Three - Programming with .NET Assemblies

Console.WriteLine("10 + 84 is {0}.", ans);

Chapter 9 - Understanding .NET Assemblies

Console.ReadLine(); // Wait for user key-press.

Chapter 10 - Processes, AppDomains, Contexts, and Threads

}

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming

}

Part Four - Leveraging the .NET Libraries

// The C# calculator.

Chapter 12 - Object Serialization and the .NET Remoting Layer

public class Calc

Chapter 13 - Building a Better Window (Introducing Windows Forms)

{

Chapter 14 - A Better Painting Framework (GDI+)

// A single method.

Chapter 15 - Programming with Windows Forms Controls public int Add(int x, int y)

Chapter 16 - The System.IO Namespace

{ return x + y; }

Chapter 17 - Data Access with ADO.NET

}

Part Five - Web Applications and XML Web Services

}

Chapter 18 - ASP.NET Web Pages and Web Controls

Chapter 19 - ASP.NET Web Applications

ChaptOncerthe20 C#- XMLcompilerWeb Services(csc.exe) compiles this source code file, you end up with a single file *.exe

assembly that contains a manifest, CIL instructions, and metadata describing each aspect of the Calc and

Index

CalcApp classes. For example, if you peek inside this binary using ildasm.exe (examined a little later in this

List of Figures

chapter) you find the Add() method is represented using CIL such as the following:

List of Tables

.method public hidebysig instance int32 Add(int32 x, int32 y) cil managed

{

.locals init ([0] int32 CS$00000003$00000000)

language produces the same underlying CIL. Therefore, all languages are able to interact within a well-

C# and the .NET Platform, Second Edition defined binary arena.

by Andrew Troelsen ISBN:1590590554

Furthermore, givenApressthat©CIL2003is(1200platformpages)agnostic, the .NET runtime is poised to become a platformindependent architecture,This comprehensiveproviding thetextsamestartsbenefitswith a briefJavaoverdevelopersiew of thehave grown accustomed to (i.e., the potential of aC#singlelanguagecode baseand thenrunningquicklyon movesnumerousto keyoperatingt chnicalsystems)and . In fact, there is an

architectural issues for .NET developers.

international standard for a large subset of the .NET platform and implementations already exist on a few non-Windows operating systems. For example, you can run basic C# programs on both FreeBSD Unix

and Apple (under OS X) platforms already. Unlike Java however, .NET allows you to build applications in

Table of Contents

a language-independent fashion. Thus, .NET has the potential to allow you to develop an application in

C# and the .NET Platform, Second Edition

any language and have it run on any platform.

Introduction

Part OneNote- IntroducingI'll commentC#a bitandmorethe .NETon thePlatformplatform-independent nature of .NET at the conclusion of this

Chapter 1 chapter- The Philosophy. of .NET

Chapter 2 - Building C# Applications

Part Two - The C# Programming Language

Chapter 3 - C# Language Fundamentals

Chapter 4 - Object-Oriented Programming with C#

Chapter 5 - Exceptions and Object Lifetime

Chapter 6 - Interfaces and Collections

Chapter 7 - Callback Interfaces, Delegates, and Events

Chapter 8 - Advanced C# Type Construction Techniques

Part Three - Programming with .NET Assemblies

Chapter 9 - Understanding .NET Assemblies

Chapter 10 - Processes, AppDomains, Contexts, and Threads

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming

Part Four - Leveraging the .NET Libraries

Chapter 12 - Object Serialization and the .NET Remoting Layer

Chapter 13 - Building a Better Window (Introducing Windows Forms)

Chapter 14 - A Better Painting Framework (GDI+)

Chapter 15 - Programming with Windows Forms Controls

Chapter 16 - The System.IO Namespace

Chapter 17 - Data Access with ADO.NET

Part Five - Web Applications and XML Web Services

Chapter 18 - ASP.NET Web Pages and Web Controls

Chapter 19 - ASP.NET Web Applications

Chapter 20 - XML Web Services

Index

List of Figures

List of Tables

The Role ofC#.NETand theType.NET Platform,MetadataSecond Edition

COM programmers are without a doubt familiar with the Interface Definition Language (IDL). IDL is a

Apress © 2003 (1200 pages)

"metalanguage" that is used to describe the types contained within a given COM server. IDL is compiled

This comprehensive text starts with a brief overview of the

into a binary formatC#(termedlanguageaandtypethenlibrary)quicklyusingmovesthe midlto key.exetechnicalcompiler,andwhich can then be used by a COMaware language toarchitecturalmanipulateissuthescontainedfor .NET developerstypes. .

In addition to describing the types within a COM binary, IDL has minimal support to describe characteristics

TableaboutoftheContentsCOM binary itself, such as its current version (e.g., 1.0, 2.0, or 2.4) and intended locale (e.g., C#English,and theGerman,.NET Platform,Urdu, Russian)Second Edition. The problem with COM metadata is that it may or may not be present

and it is often the role of the programmer to ensure the underlying IDL accurately reflects the internal

Introduction

types.

Part One - Introducing C# and the .NET Platform

Chapter 1 - The Philosophy of .NET

The .NET Framework makes no use of IDL whatsoever. However, the spirit of describing the types residing within a particular binary lives on. In addition to the underlying CIL instructions, a .NET assembly

contains full, complete and accurate metadata. Like COM IDL, .NET metadata describes each and every

Chapter 3 - C# Language Fundamentals

type (class, structure, enumeration, and so forth) defined in the binary, as well as the members of each

Chapter 4 - Object-Oriented Programming with C# type (properties, methods, events, and so on).

Chapter 5 - Exceptions and Object Lifetime

ChapterFurthermore,6 - Interfacesthe .NETandmanifestCollections(which as you recall is metadata describing the assembly itself) is far Chaptmorercomplete7 - CallbackthanInterfaces,IDL, in thatDelegates,it also describesand Eventseach externally referenced assembly that is required by

the executing assembly to operate correctly. Because .NET metadata is so wickedly meticulous,

Chapter 8 - Advanced C# Type Construction Techniques

assemblies are completely selfdescribing entities. So much so in fact, .NET binaries have no need to be

Part Three - Programming with .NET Assemblies

registered into the system registry (more on that little tidbit later in the text).

Chapter 9 - Understanding .NET Assemblies

Chapter 10 - Processes, AppDomains, Contexts, and Threads

ChapterA Quick11 - TypeMetadataReflection, LateExampleBinding, and Attribute-Based Programming

Part Four - Leveraging the .NET Libraries

To illustrate the format of .NET metadata, let's take a look at the metadata that has been generated for

Chapter 12 - Object Serialization and the .NET Remoting Layer

the Add() method of the C# Calculator class you examined previously (the metadata generated for the VB

Chapter 13 - Building a Better Window (Introducing Windows Forms)

.NET Add() method is similar). Using the ildasm.exe utility (examined at the end of this chapter) you can

Chapter 14 - A Better Painting Framework (GDI+)

view your assembly's metadata by hitting the Ctrl+M keystroke. Within the resulting "MetaInfo" window, you

Chapter 15 - Programming with Windows Forms Controls

will find a description of the Add() method looking something like the following::

Chapter 16 - The System.IO Namespace

RVA : 0x00002064

Index

ImplFlags : [IL] [Managed] (00000000)

List of Figures

CallCnvntn: [DEFAULT]

List of Tables

hasThis

ReturnType: I4

2 Arguments

Argument #1: I4

Argument #2: I4

2Parameters

(1)ParamToken : (08000001) Name : x flags: [none] (00000000)

(2)ParamToken : (08000002) Name : y flags: [none] (00000000)

Here you can see that the Add() method, return type, and method arguments have been fully described by the C# compiler. Needless to say, metadata is used by numerous aspects of the .NET runtime environment, as well as by various development tools. For example, the IntelliSense feature provided by Visual Studio .NET is made possible by reading an assembly's metadata at design time. Metadata is also used by various object browsing utilities, debugging tools, and even the C# compiler itself. To be sure, metadata is the backbone of numerous .NET technologies such as .NET Remoting, reflection services,

and object serialization.

C# and the .NET Platform, Second Edition

Apress © 2003 (1200 pages)

This comprehensive text starts with a brief overview of the C# language and then quickly moves to key technical and architectural issues for .NET developers.

Table of Contents

C# and the .NET Platform, Second Edition

Introduction

Part One - Introducing C# and the .NET Platform

Chapter 1 - The Philosophy of .NET

Chapter 2 - Building C# Applications

Part Two - The C# Programming Language

Chapter 3 - C# Language Fundamentals

Chapter 4 - Object-Oriented Programming with C#

Chapter 5 - Exceptions and Object Lifetime

Chapter 6 - Interfaces and Collections

Chapter 7 - Callback Interfaces, Delegates, and Events

Chapter 8 - Advanced C# Type Construction Techniques

Part Three - Programming with .NET Assemblies

Chapter 9 - Understanding .NET Assemblies

Chapter 10 - Processes, AppDomains, Contexts, and Threads

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming

Part Four - Leveraging the .NET Libraries

Chapter 12 - Object Serialization and the .NET Remoting Layer

Chapter 13 - Building a Better Window (Introducing Windows Forms)

Chapter 14 - A Better Painting Framework (GDI+)

Chapter 15 - Programming with Windows Forms Controls

Chapter 16 - The System.IO Namespace

Chapter 17 - Data Access with ADO.NET

Part Five - Web Applications and XML Web Services

Chapter 18 - ASP.NET Web Pages and Web Controls

Chapter 19 - ASP.NET Web Applications

Chapter 20 - XML Web Services

Index

List of Figures

List of Tables