2003 sams ms® visual c sharp net 2003 developers cookbo

Chapter 4, "Creating and Using .NET Collections," covers the fundamentalcollection types in the .NET Framework, including searching andsorting those collections, as well as recipes that

description of the topic at hand and then gives you the goods - recipes that explain a brief description of the task, the technique and comments about the technique chosen

by C# experts, Mark Schmidt and Simon Robinson.

Copyright © 2004 by Sams Publishing

All rights reserved No part of this book shall be reproduced,stored in a retrieval system, or transmitted by any means,

electronic, mechanical, photocopying, recording, or otherwise,without written permission from the publisher No patent

liability is assumed with respect to the use of the informationcontained herein Although every precaution has been taken inthe preparation of this book, the publisher and author assume

no responsibility for errors or omissions Nor is any liabilityassumed for damages resulting from the use of the informationcontained herein

regarded as affecting the validity of any trademark or servicemark

Warning and Disclaimer

as accurate as possible, but no warranty or fitness is implied.The information provided is on an "as is" basis The authors andthe publisher shall have neither liability nor responsibility to anyperson or entity with respect to any loss or damages arisingfrom the information contained in this book

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Sams Publishing offers excellent discounts on this book whenordered in quantity for bulk purchases or special sales For

Mark Schmidt

Mark Schmidt is a software engineer at Hewlett-Packard His

current research is in the area of advanced custom user

interfaces Part of this work was the topic of a talk he gave atthe 2001 VSLive! Conference in San Francisco Mark has written

in straight computer programming and ended up at Lucent

Technologies doing mostly Windows COM programming, beforefinally becoming self-employed, combining writing and freelancesoftware development He has an extremely broad experience

of programming on Windows These days, his core specialism is.NET programming, and he is comfortable coding in C++, C#,

VB, and IL and has skills ranging from graphics and Windows

Forms to ASP.NET, directories, data access, Windows services,and the native Windows API.

So many people were involved or touched in one way or

another by my time spent on this book, but unfortunately, Ican't list you all

To my wife, Cher, and children, Jordan, Jake, Jonah, and

Mallorie You are my life and the reason I strive to succeed Ilove you all more than words can convey

To my Dad, who instilled in me the principle of working hard soyou can play hard later

To the many editors and people at Sams Publishing and

especially to Neil Rowe You all know how to make a hard jobfun and worthwhile, and I will always treasure the relationshipNeil and I started

Damon, Mike, and Byron, you guys put the fun in my life

Thanks for pulling me out of my hole once in a while and forbeing the close friends you guys are

Charlie, thanks for making me look good in front of my peers

To my extended family at River Rock Church, thank you forshowing so much love and support It brings me comfort andpeace to see the love of our Lord in all your faces

Finally, I'd like to especially acknowledge my two brothers,Daron and Scott, who have stuck by my side and each other'sthrough all of life's trials Brothers until the end, I love youguys

Mark Schmidt

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When Visual C# NET first arrived on the scene, developers

everywhere were hit with a vast wave of documentation andtutorials from magazine articles, books, and Web sites The

obligatory "Hello World" programs were popping up left and

right as developers began their path to understanding this newlanguage created by Microsoft Those days of learning this

exciting new technology are now gone for some developers, andthey now need more in-depth materialmaterial that corresponds

constructed to first show you how to accomplish a task using acertain technique and then to follow with comments that

provide a closer inspection of the solution

Along with the immense array of task-specific recipes is a largecollection of source code, which is freely available on the SamsWeb site, http://www.samspublishing.com Most recipes in thisbook utilize source code contained within an application

developed for the task it is explaining Even though some of thesource code might be terse and to the point, some of the

applications would make a great stepping stone to larger, moreinvolved solutions For instance, Chapter 10, "Programming

Graphics with GDI+," uses the source code from an image-editing application with full support for image scaling, cropping,rotation, and even a print preview dialog Chapter 8, "Windows

Studio NET 2003 Integrated Development Environment (IDE).Additionally, Chapter 13, "XML in NET," contains a full XML

impossible task Microsoft Visual C# NET 2003 Developer's

Cookbook provides the help you need when you just want to

know how to perform a single task, and it offers real-world,application-specific information The companion Web site forthis book, http://www.csharpcookbook.com, provides additionalmaterial and a way to contact the authors for more information

Part I , The C# Language

One of the more subtle defects that occur in code is failure torecognize the various rules related to operators, expressions,and control structures Chapter 1, "Operators, Expressions, andControl Structures," details those rules and how best to utilizethem, including topics such as operator precedence and

associativity, data type conversions, and understanding logicalexpressions

C# is an object-oriented programming language and as suchplaces a strong emphasis on the use of objects within the NETFramework and the code that you write Chapter 2, "Objectsand Components," starts with basic recipes concerning objectcreation and ends with advanced topics such as polymorphism,abstract classes, and multiple interface inheritance

As you see in Chapter 3, "Strings and Regular Expressions,"strings play a major role in any programming language The.NET Framework contains a rich set of classes that aid the

developer when working with this data type Furthermore,

regular expressions allow you to take string data and performinput validation and substring replacement

Very rarely will you work with single bits of data when creating

an application More often than not, you need to utilize

collections to store several items of a similar type Chapter 4,

"Creating and Using NET Collections," covers the fundamentalcollection types in the NET Framework, including searching andsorting those collections, as well as recipes that aid in creatingyour own collection type

Delegates and events form the eventing system within the NETFramework Although a majority of event handlers respond touser-interface interaction, the model used in the NET

Framework allows any object to fire or receive events Chapter

Application errors are an everyday occurrence Not to be

confused with regular defects, exceptions and errors are usedextensively within the NET Framework to respond appropriatelywhen something doesn't work correctly In Chapter 6,

"Exceptions in Error Handling," you'll see various techniquesoutlining the proper way to catch and throw exceptions as well

as pass exceptions on to other objects

Part II , User Interface and Graphics

Windows Forms is the technology responsible for client-side

user interfaces Coupled with this technology is the rich designsupport built into Visual Studio NET 2003 Chapter 7, "WindowsForms," begins with several recipes aimed at creating basic

Windows Forms applications and ends with more advanced

topics, such as Multiple Document Interface (MDI) user

interfaces

Without controls, a Windows Form is just a window The NETFramework contains an extensive list of controls that you canadd to a Windows Form with a simple drag and drop from thedesigner Several recipes in Chapter 8, "Windows Forms

Controls," demonstrate various ways to control certain commoncontrols, whereas others show methods to harness the WindowsForms designer to create compelling user interfaces

Although the NET Framework contains an exhaustive list of

controls, there will always be room for more Chapter 9, "UserControls," shows different techniques you can utilize to createour own NET Windows Form control and how to plug the

Localizing an application is a task that should be solidified

during an application's design Without a game plan and without

a toolset to enable that plan, you might be playing catch-upduring the localization phase As shown in Chapter 11,

localization and resource classes of the NET Framework tomake localization easier

Part III , Data Access

For data to remain persistent, it must be written to a long-termstorage medium such as a hard disk Chapter 12, "File I/O andSerialization," looks at various techniques involved with file

input and output Furthermore, it also covers serialization, theact of saving an object's state, by looking at the various

application configuration files to method invocation on remoteobjects

Databases have transformed the Internet from static Web pages

to truly dynamic information systems You see in Chapter 14,

"Database Programming with ADO.NET," that ADO.NET is the.NET solution for interacting with different database

technologies, from Microsoft Access to more industrial-level

database systems such as SQL Server

Part IV , Internet and Networking

Sockets form the underlying layer of network programming.Chapter 15, "Network Programming with Sockets," looks at

different ways of programming sockets as well as discusses

methods to formulate your own communication protocol Some

of the advanced techniques include accessing data through aproxy server and performing asynchronous Web transfers

The successor to Active Server Pages (ASP), ASP.NET

transforms dynamic Web pages into feature-laden Web

applications In Chapter 16, "ASP.NET," you will see techniquesdemonstrating everything from creating, manipulating, and

In the past, communication between disparate objects across anetwork was a lesson in perseverance for most developers

Remoting in the NET Framework was created not only to makethis communication much easier but also to provide great

flexibility and power for creating distributed applications

Chapter 18, "Remoting," covers various aspects of remoting,including server-activated singleton objects and custom channelsinks for logging

Part V , Deployment and Security

The main deployment unit of a NET application is the assembly.Assemblies were created to combat the inconsistent deployment

of class libraries and version incompatibilities Chapter 19,

"Assemblies," shows that the NET Framework contains a vastarray of processes to follow when working with assemblies,

including strongly named assemblies, and techniques to followwhen creating subsequent versions of existing assemblies

Sometimes regarded as the last step in application design,

installation is also one of the most important items to plan andimplement In Chapter 20, "Installation," you'll see the

techniques needed to create a robust installation of your

application, starting with the creation of installation packagesand followed by more advanced techniques, including

installation of assemblies into the Global Assembly Cache

(GAC)

Security issues within the development community have seen afocused increase Chapter 21, "Securing Code," covers severaldifferent facets of programming, including authentication, codeexecution permissions, and licensing

Part VI , Advanced Topics

Threading gives you the ability to run two or more simultaneousprogramming tasks However, it also opens the possibility fordata corruption if those tasks attempt to manipulate the samearea of memory You use synchronization to prevent this

possibility from happening Chapter 22, "Threading and

Synchronization," discusses several different techniques you canuse to create multithreaded applications

The ability to programmatically inspect objects at runtime is

known as reflection Reflection allows you not only to view the

contents of assemblies, modules, and data types but also todynamically create assemblies at runtime Chapter 23,

"Reflection," shows different techniques for reflection, such ascreating a plug-in architecture and performing dynamic methodinvocation

The Component Object Model (COM) is one of the oldest butmost widely used Windows technologies Because a vast array

of libraries and controls utilize COM, the NET Framework

contains the necessary toolset to use COM objects in NET

applications as well as NET objects within COM-based

applications Chapter 24, "COM Interoperability," discusses thistoolset

SmartPhones Chapter 26, "Smart Device Extensions," explainssome of the key differences you'll encounter when creatingdevice applications, including techniques related to installation,data retrieval, and Compact NET Framework classes.

Chapter 1 Operators, Expressions, and Control Structures

For several generations, the most widely sold toys have beenthose that allow you to take small simple objects and combinethem to create a replica of some real-world object Initially

starting out as a large pile of plastic blocks with varying shapesand colors, they can transform into a multistage ignition rocketship or an elegant mansion without a roof

Toys aren't the only place we see this sort of design Almosteverywhere you look, this piecewise refinement is evident inmany facets of everyday life Cars aren't built using a myriad ofnon-connecting objects but rather are assembled from smallerpieces to form the engine, for instance, which is then used as acomponent in the final automobile Using another example, acompany contains employees who form a team These teamscombine to form a section or business unit, and these units

group together to form the corporation In fact, this type of

organization doesn't just make sense in the physical realm but

is prevalent in many natural things as well

Based on this concept, it comes as no surprise that software islogically divided into smaller pieces that contribute to a solutionwhen assembled At the lower levels of the programming

language construct hierarchy are the operator, the expression,and the control structure An expression is any group of

operators and operands that are combined to perform sometype of computation, such as setting a variable, calling a

function, or performing a system-related task

In this chapter, we look at all the various C# language elementsthat are available to construct an application From the basiclayout of a small console application to using overloaded

operators to change the semantic meaning of objects, this

chapter points out the various options you have at your disposal

to efficiently design your next Visual C# NET application

Comments

For most of this chapter and in several projects throughout thisbook, you'll find yourself working with console-based

applications Their minimalist nature allows you to concentrate

on the topic being discussed without having to traverse throughextraneous, potentially distracting code

Even though it is just a simple console-based application thatcurrently provides no functionality, it does serve as a good

illustration for some of the various pieces that make a C#

application Once you create your project, the Visual Studio.NET IDE opens the application's main program file, which

should look similar to Listing 1.1

example, the namespace could be Automobile.

On the first line, the program is letting the compiler know that itwants to use some of the objects within the System namespace.Therefore, anytime you want to use one of these objects, you

However, we recommend that you do get into the habit of using