Creating Your First C# Windows Program

Creating Your First C#

Windows Program

 What’s a program?

What is a program? In one sense, a Windows program is an executable file that

you can run by double-clicking its icon. For example, the version of Microsoft

Word that I’m using to write this book is a program. You call that an executable

program, or executable for short. The names of executable program files generally

end with the extension .exe.

But a program is something else, as well. An executable program consists

of one or more source files. A C# program file is a text file that contains a

sequence of C# commands, which fit together according to the laws of C#

grammar. This file is known as a source file, probably because it’s a source of

frustration and anxiety.

What’s C#?

The C# programming language is one of those intermediate languages that

programmers use to create executable programs. C# fills the gap between the

powerful-but-complicated C++ and the easy-to-use-but-limited Visual Basic —

well, versions 6.0 and earlier, anyway. (Visual Basic’s newer .NET incarnation

is almost on par with C# in most respects. As the flagship language of .NET,

C# tends to introduce most new features first.) A C# program file carries the

extension .CS.

C# is

_ Flexible: C# programs can execute on the current machine, or they can

be transmitted over the Web and executed on some distant computer.

_ Powerful: C# has essentially the same command set as C++, but with the

rough edges filed smooth.

_ Easier to use: C# modifies the commands responsible for most C++

errors so you spend far less time chasing down those errors.

_ Visually oriented: The .NET code library that C# uses for many of its

capabilities provides the help needed to readily create complicated display

frames with drop-down lists, tabbed windows, grouped buttons,

scroll bars, and background images, to name just a few.

_ Internet friendly: C# plays a pivotal role in the .NET Framework,

Microsoft’s current approach to programming for Windows, the Internet,

and beyond. .NET is pronounced dot net.

_ Secure: Any language intended for use on the Internet must include

serious security to protect against malevolent hackers.

Finally, C# is an integral part of .NET.

What’s .NET?

.NET began a few years ago as Microsoft’s strategy to open up the Web to

mere mortals like you and me. Today it’s bigger than that, encompassing

everything Microsoft does. In particular, it’s the new way to program for

Windows. It also gives a C-based language, C#, the simple, visual tools that

made Visual Basic so popular. A little background will help you see the roots

of C# and .NET.

Internet programming was traditionally very difficult in older languages like C

and C++. Sun Microsystems responded to that problem by creating the Java

programming language. To create Java, Sun took the grammar of C++, made it

a lot more user friendly, and centered it around distributed development.

When programmers say “distributed,” they’re describing geographically dispersed

computers running programs that talk to each other — in many cases,

via the Internet.

When Microsoft licensed Java some years ago, it ran into legal difficulties with

Sun over changes it wanted to make to the language. As a result, Microsoft

more or less gave up on Java and started looking for ways to compete with it.

Being forced out of Java was just as well because Java has a serious problem:

Although Java is a capable language, you pretty much have to write your

entire program in Java to get its full benefit. Microsoft had too many developers

and too many millions of lines of existing source code, so Microsoft had

to come up with some way to support multiple languages. Enter .NET.

.NET is a framework, in many ways similar to Java’s libraries, because the C#

language is highly similar to the Java language. Just as Java is both the language

itself and its extensive code library, C# is really much more than just

the keywords and syntax of the C# language. It’s those things empowered by

a thoroughly object-oriented library containing thousands of code elements

that simplify doing about any kind of programming you can imagine, from

Web-based databases to cryptography to the humble Windows dialog box.

The previous generation platform was made up of a hodgepodge of tools

with cryptic names. .NET updates all that with Visual Studio 2005, with more

focused .NET versions of its Web and database technologies, newer versions

of Windows, and .NET-enabled servers. .NET supports emerging communication

standards such as XML and SOAP rather than Microsoft’s proprietary

formats. Finally, .NET supports the hottest buzzwords since object-oriented:

Web Services.

Microsoft would claim that .NET is much superior to Sun’s suite of Web tools

based on Java, but that’s not the point. Unlike Java, .NET does not require

you to rewrite existing programs. A Visual Basic programmer can add just a

few lines to make an existing program “Web knowledgeable” (meaning that

it knows how to get data off the Internet). .NET supports all the common

Microsoft languages and more than 40 other languages written by third-party

vendors (see www.gotdotnet.com/team/lang for the latest list). However,

C# is the flagship language of the .NET fleet. C# is always the first language to

access every new feature of .NET.

What is Visual Studio 2005?

What about Visual C#?

You sure ask lots of questions. The first “Visual” language from Microsoft was

Visual Basic, code-named “Thunder.” The first popular C-based programming

language from Microsoft was Visual C++. Like Visual Basic, it was called

“Visual” because it had a built-in graphical user interface (GUI — pronounced

gooey). This GUI included everything you needed to develop nifty-giffy C++

programs.

Eventually, Microsoft rolled all its languages into a single environment —

Visual Studio. As Visual Studio 6.0 started getting a little long in the tooth,

developers anxiously awaited Version 7. Shortly before its release, however,

Microsoft decided to rename it Visual Studio .NET to highlight this new environment’s

relationship to .NET.

That sounded like a marketing ploy to me until I started delving into it. Visual

Studio .NET differed quite a bit from its predecessors — enough so to warrant

a new name. Visual Studio 2005 is the successor to the original Visual Studio

.NET. (See Bonus Chapter 4 on the CD for a tour of some of Visual Studio’s more

potent features.)

Microsoft calls its implementation of the language Visual C#. In reality, Visual

C# is nothing more than the C# component of Visual Studio. C# is C#, with or

without the Visual Studio.

Creating a Windows Application with C#

To help you get your feet wet with C# and Visual Studio, this section takes you

through the steps for creating a simple Windows program. Windows programs

are commonly called Windows applications, WinApps or WinForms apps for

short.

Because this book focuses on the C# language, it’s not a Web-programming

book, a database book, or a Windows programming book per se. In particular,

this chapter constitutes the only coverage of Windows Forms visual programming.

All I have room to do is give you this small taste.

In addition to introducing Windows Forms, this program serves as a test of

your Visual Studio environment. This is a test; this is only a test. Had it been

an actual Windows program . . . Wait, it is an actual Windows program. If you

can successfully create, build, and execute this program, your Visual Studio

environment is set up properly, and you’re ready to rock.

Creating the template

Writing Windows applications from scratch is a notoriously difficult process.

With numerous session handles, descriptors, and contexts, creating even a

simple Windows program poses innumerable challenges.

Visual Studio 2005 in general and C# in particular greatly simplify the task of

creating your basic WinApp. To be honest, I’m a little disappointed that you

don’t get to go through the thrill of doing it by hand. In fact, why not switch

over to Visual C++ and . . . okay, bad idea.

Because Visual C# is built specifically to execute under Windows, it can shield

you from many of the complexities of writing Windows programs from scratch.

In addition, Visual Studio 2005 includes an Applications Wizard that builds

template programs.

Typically, template programs don’t actually do anything — at least, not anything

useful (sounds like most of my programs). However, they do get you

beyond that initial hurdle of getting started. Some template programs are reasonably

sophisticated. In fact, you’ll be amazed at how much capability the

App Wizard can build on its own.

After you’ve completed the Visual Studio 2005 installation, follow these steps

to create the template:

1. To start Visual Studio, choose Start➪All Programs➪Microsoft Visual

Studio 2005➪Microsoft Visual Studio 2005, as shown in Figure 1-1.

After some gnashing of CPU teeth and thrashing of disk, the Visual

Studio desktop appears. Now things are getting interesting.

2. Choose File➪New➪Project, as shown in Figure 1-2.

Visual Studio responds by opening the New Project dialog box, as shown

in Figure 1-3.

A project is a collection of files that Visual Studio builds together to

make a single program. You’ll be creating C# source files, which carry

the extension .CS. Project files use the extension .CSPROJ.

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