Introduction to C

1
Introduction to C

• Introduction to .NET

2
Agenda

• What is .NET?
• C as related to VB, C, and Java
• MSIL
• Overview of Object-Oriented Programming (OOP)
• The Integrated Development Environment
• Your first C program

3
.NET Overview
4
What is .NET?

• Development Framework
• Provides an API (application programming
  interface) to Windows
• Convergence of multiple Microsoft technologies

5
Doing Cool Things Easily!

• Major investment by Microsoft to see .NET succeed
  (80 of MS RD)
• New languages
• C (extends Java/VB/C)
• VB.NET (strengthens VB 6.0)
• Devices
• Compact .NET Framework runs on PDAs, cell phones,
  game boxes, etc.

6
.NET Framework Architecture
Microsoft Visual Basic .NET
C
C
Microsoft JScript

Microsoft Visual Studio .NET
Common Language Specification
Framework Class Library
Common Language Runtime
Windows
LINUX
7
What Does .NET Offer?

• Platform independence
• Language independence
• Modern language features
• Improvements to ADO and VB
• RAD for C/C (finally!) via C

8
.NET Framework Classes
9
C as Related to Other Languages
10
C and other Modern Languages

• C is the evolution of VB, Java, and C
• Leverages the Rapid Application Development (RAD)
  drag and drop of VB
• Leverages the strong language features of C and
  Java
• Very Java-like
• Switching from C to another language should
  prove easy to you

11
Platform Independence

• Write once, run anywhere
• Compile to MSIL (open standard)
• Deploy to many operating systems
• The CLR handles JIT to native code
• Akin to the Java Virtual Machine (JVM)

12
Language Independence
VB API
Java WFC
C MFC
Each language uses different APIs
13
Language Independence
VB API
Java WFC
C MFC
.NET CLR
Unified, object-oriented, hierarchical, extensible
set of class libraries
14
RAD in C

• Windows development in C
• Win32 API or MFC
• Lots of nasty details
• 300 lines of code (6 pages!)just for Hello
  World
• No easy way to Rapid Application Development

15
The Old Way Just to Create a Window?

• hWnd CreateWindow( "GenericAppClass","Generic
  Application", WS_OVERLAPPEDWINDOWWS_HSCROLLWS_VS
  CROLL,0,0,CW_USEDEFAULT,CW_USEDEFAULT,NULL,N
  ULL,hInstance,NULL )

16
Creating a Window in C

• namespace HelloWorld
• public partial class Form1 Form
• public Form1()
• InitializeComponent()
• static class Program
• STAThread
• static void Main()
• Application.EnableVisualStyles()
• Application.Run(new Form1())

17
RAD in C (cont)

• Drag-Drop interface building (ala VB)
• Auto-generates code for control properties
• Collapsible code regions
• Intellisense (code complete)
• Dynamic help/reference

18
Microsoft Intermediate Language (MSIL)
19
MSIL

• Microsoft Intermediate Language
• Similar to Java Bytecode
• Language neutral and platform neutral
• Go from any .NET language to MSIL
• Go from MSIL to any native machine code

20
MSIL Language Independence

• Write in any .NET language
• C, VB.NET, J, C.NET, OTHERS!
• Compile to MSIL
• JIT compilation to native code

VB.NET
C
MSIL
Native

Vis J
21
Introduction to Object-Oriented Programming
22
Object-Oriented Programming

• We will discuss OOP later in detail
• But since all C programs are Object-oriented,
  you need to know basics
• A class combines data and actions (also known as
  methods/functions)
• A Person class combines information about hair
  color, age, weight, etc. along with actions like
  run, eat and sleep.
• An object is an instance of a class
• Alice is an object/instance of the Person
  class consequently, she has a specific hair
  color, age, weight, etc.
• Bob is another object/instance of the Person
  class he has different hair color, age, weight,
  etc. from Alice
• Object communicate by sending messages

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Why Talk about OOP?

• For a while, well gloss over the details of the
  OOP in C
• Well focus on general ideal like how to store
  and manipulate data
• As a result, youll see a lot of code that well
  ignore for now
• Assume the magic works well discuss in detail
  whats going on later

24
Integrated Development Environment (IDE)
25
Various IDEs

• The IDE serves to help write your programs
• Certainly you can just use Notepad and the
  console-based compiler
• But the IDE makes building, testing, and running
  your programs MUCH easier

26
Current C IDEs

• MANY different IDEs for C
• .NET Framework 1.0 / 1.1
• Studio .NET 2002 (deprecated)
• Studio .NET 2003 (lacks some new features)
• .NET Framework 2.0
• Studio .NET 2005 Beta
• Studio .NET 2005 Beta 2
• Studio .NET 2005 Express for C (lightweight)
• Studio .NET 2005 Express for Web Development

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The C Studio .NET 2005 Express IDE
Solution Explorer
Controls Toolbox
Form Editor/Designer
Properties Editor
28
Your First C Program
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Responding to The Button Click Event

• private void buttonCompute_Click(object sender,
  EventArgs e)
• TimeSpan difference
• DateTime currentTime DateTime.Now
• int age
• difference currentTime.Subtract(dateTimePicker
  BD.Value)
• age difference.Days
• MessageBox.Show("You are " age " days
  old.")

30
Conclusion

• You should know a little bit about .NET
• MSIL
• How C relates to Java, C, and VB
• You should have an idea of how to use the C
  Studio .NET 2005 Express IDE
• You should know how to create a form
• You should be familiar with the Button, Label,
  and DateTimePicker classes
• You should know how to display a message box