1' Introduction to Computers, Internet and Visual Basic 'NET

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1. Introduction to Computers, Internet and Visual
Basic .NET

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Lecture Outline

• Visual Programming Environment.
• Introduction to Visual Studio.
• Introduction to .NET.
• Introduction to visual studio .NET
• .NET Framework.
• Major Components of .NET Framework
• Namespaces

• Framework class library (FCL)
• Common Language Runtime (CLR)
• Common Language Specification (CLS)

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Visual Programming Environment

• Environment which allows the use of visual
  expressions (such as graphics, drawings,
  animation or icons) in the process of
  programming.

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Visual Programming Environment

• The technique of Visual Programming allows
  programmers to create GUI without writing any
  code.
• Microsoft Visual Studio .NET is a visual
  programming environment.

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• First what is Visual Studio ??
• Second what is .NET ??
• Any ideas ??????

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1. Introduction to Visual Studio

• Is the main Integrated Development Environment
  (IDE) from Microsoft.
• It can be used to develop console and GUI
  applications.

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1. Introduction to Visual Studio
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1. Introduction to Visual Studio

• Visual Studio includes a code editor supporting
  some features like IntelliSense.

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Introduction to Visual Studio Features

• IntelliSense shows the available classes and the
  methods and properties available on those
  classes.
• Designers Visual Studio includes visual WYSIWYG
  designers for GUI and other applications.
• Debugging is the ability to step through your
  application line by line as it is executing.
• Organization it provides intuitive methods for
  organizing your various code files into projects
  and your various projects into solutions.

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1. Introduction to Visual Studio

• Visual Studio 97
• Visual Studio 6.0 (1998)
• Visual Studio .NET (2002) - New programming
• language that targets .NET
• Visual Studio .NET 2003 - First release to
  support for
• developing programs for mobile
  devices.
• Visual Studio 2005 Removes .NET only from name.
• Visual Studio 2008 Focuses on Windows Vista.
• Visual Studio 2010 -- Under development.

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• Now what is .NET ?

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2. Introduction to .NET

• When you hear the name .NET, it gives a feeling
  that it is something to do only with internet or
  networked applications.
• Even though it is true that .NET provides solid
  foundation for developing such applications it is
  possible to create many other types of
  applications.

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2. Introduction to .NET

• The .NET is one over which Web-Based applications
  can be distributed to variety of devices ( such
  as cell phones ) and desktop computers.
• Offers a new programming model that allows
  programs , created in disparate programming
  languages , to communicate with each other.
• Additional information available at Microsoft Web
  site www.microsoft.com/net

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2. Introduction to .NET

• You can develop such varied types of
  applications. Thats fine. But how?

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2. Introduction to .NET

• As with most of the programming languages, .NET
  has a complete Software Development Kit (SDK) -
  more commonly referred to as .NET Framework SDK
• It provides classes, interfaces and language
  compilers necessary to program for .NET.
• Additionally it contains excellent documentation
  and Quick Start tutorials that help you learn
  .NET technologies with ease.

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2. Introduction to .NET

• Good news is that - .NET Framework SDK is
  available FREE of cost. You can download it from
  the MSDN web site.
• This means that if you have machine with .NET
  Framework installed and a text editor such as
  Notepad then you can start developing for .NET
  right now!

You can download entire .NET Framework SDK
(approx 131 Mb) from MSDN web site at
http//msdn.microsoft.com/downloads/default.asp?ur
l/downloads/sample.asp?url/msdn-files/027/000/97
6/msdncompositedoc.xml
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.NET Development Tools
2. Introduction to .NET

• If you are developing applications that require
  speedy delivery to your customers and features
  like integration with some version control
  software then simple Notepad may not serve your
  purpose.
• In such cases you require some Integrated
  Development Environment (IDE).
• The new Visual Studio.NET is such an IDE. VS.NET
  is a powerful and flexible IDE that makes
  developing . NET applications a breeze.

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So.

• VS .NET VS.NET
• VS .NET is
• A Visual programming environment
• That represents the best development environment
  for the .NET platform.

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Introduction to VS .NET

• VS .NET comes with
• the .NET Framework,
• several programming languages including Visual
  Basic, Visual C, and Visual C.

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Major Components of .NET Framework 
Framework Class Library (FCL)
Common Language Specification (CLS)
Common Language Runtime (CLR)
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Major Components of .NET Framework 

• 1- Framework class library (FCL)
• OO, Pre-packaged classes ready for reuse.
• Used by any .NET language.
• It contains around 3400 classes classified
  logically into namespaces. Each class contains
  numerous methods and properties which you will
  use for your programming tasks.

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2 -Common Language Runtime (CLR)
Major Components of .NET Framework 

• Central part of framework is the virtual machine
  component of the .NET framework. All .NET
  programs execute under the supervision of the
  CLR.
• Compilation process Two compilations take place
  
• Programs compiled to Microsoft Intermediate
  Language (MSIL)
• Defines instructions for CLR
• MSIL code translated into machine code
• Machine code for a particular platform

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CLR Execution Model
Source code
VB
C
C
Compiler
Compiler
Compiler
Managed code
MSIL Code
Common Language Runtime
Machine Code
Operating System Services
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Major Components of .NET Framework 

• Why two compilations?
• Platform independence - Portability 
• .NET Framework can be installed on different
  platforms
• Execute .NET programs without any modifications
  to code
• Language independence Inter-operability
• .NET programs not tied to particular language
• Programs may consist of several .NET-compliant
  languages
• Programs written in different languages are all
  compiled into MSILthe different parts can be
  combined to create a single, unified program.
• Execution-management features
• Manages memory, security and other features
• Relieves programmer of many responsibilities
• More concentration on program logic

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Major Components of .NET Framework 

• 3- Common Language Specification (CLS)
• The CLR allows objects created in one language be
  treated as equal citizens by code written in a
  completely different language.
• To make this possible, Microsoft has defined the
  CLS that details for compiler vendors the minimum
  set of features that their compilers must support
  if they are to target the runtime.
• Any language that conforms to the CLS can run on
  the CLR.

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Major Components of .NET Framework 
VB
C
C
Visual Studio.NET
JScript

CLS
WindowsForms
ASP.NET Web Services and Web Forms
WindowsForms
ADO.NET Data and XML
FCL
CLR
Operating System Services
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Namespaces

• As said earlier, FCL contains classes
  classified logically into namespaces.
• The .NET Framework is a whole lot of Classes
  (called Namespaces) and the technology to get
  those Classes to work.

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Namespaces

• Most of the built in classes are part of either
  System. or Microsoft. namespaces.
• It encapsulates a large number of common
  functions, such as file reading and writing,
  graphic rendering, and database interaction,
  among others.
• The .NET class libraries are available to all
  .NET languages.

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Namespaces

• A Namespace is a group of Classes which are
  grouped together.
• Namespaces are organized hierarchically.
• Namespaces developed by .NET team begin with
  System.

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Namespaces

• If we can explore the System namespace little
  bit, we can see it has lot of namespace. For
  example
• The System.IO Namespace groups together Classes
  that you use to read and write to a file.
• System.Windows.Forms Includes classes for
  creating Windows based forms.

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Namespaces

• System is a top-level Namespace as the leader of
  a hierarchy.
• IO and Windows would be part of this hierarchy,
  just underneath the leader.
• Each subsequent group of Classes is subordinate
  to the one the came before it.
• For example Forms is a group of Classes available
  to Windows, just as Windows is a group of Classes
  available to System.

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Namespaces

• A single form is a Class available to Forms
• System.Windows.Forms.Form
• A Button is also part of the Forms Class
• System.Windows.Forms.Button
• As too is a Textbox
• System.Windows.Forms.TextBox

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Namespaces

• Use dot syntax to connect namespaces together
• A period separates each namespace name
• System.Drawing
• System.Windows.Forms
• System.Data

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Namespaces

• Some Namespaces and their use
• System Includes essential classes and base
  classes for commonly used data types, events,
  exceptions and so on
• System.Collections Includes classes and
  interfaces that define various collection of
  objects such as list, queues, hash tables,
  arrays, etc
• System.Data Includes classes which lets us
  handle data from data sources
• System.Drawing Provides access to drawing
  methods
• System.Net Provides interface to protocols used
  on the internet
• System.Web Includes classes and interfaces that
  support browser-server communication

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The Organization of Namespaces
System namespace System
Drawing namespace System.Drawing
Windows.Forms namespace System.Windows.Forms
Data namespace System.Data
Printing namespace System.Drawing.Printing
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Parts of a Namespace

• A namespace contains
• Classes which are reference types.
• Enumerations which define a symbolic name for a
  value.
• Structures which are value types.

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Parts of a Namespace
Windows.Forms namespace System.Windows.Forms
Enumerations
Classes
Structures
Button
BorderStyle
Message
Label
FormBorderStyle
TextBox
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1. Namespace Classes

• Classes are reference types
• Variable stores the memory address of an object
  rather than the object itself
• Controls appearing in the Toolbox are all classes

Variable btnCalculate 023448
Variable contains memory address of Button
control instance
btnCalculate (Memory address 023448) Data
Caption "Calculate"
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2. Namespace Enumerations

• Enumerations define a symbolic name for a value.
• Enumerations improve code readability.
• Enumeration can be done at the place where we
  need to assign integer values for words. For
  example
• Enum ServingSizes As LongSmall 1Regular
  2Large 3
• End Enum
• The BorderStyle enumeration applies to the
  System.Windows.Forms namespace
• lblFileName.BorderStyle _ System.Windows.Form
  s.BorderStyle.FixedSingle

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3. Namespace Structures

• Structures are value types
• Store data directly in the variable
• Structures are designed to be lightweight
  alternatives to classes. In this case, the term
  lightweight means that structures use fewer
  resources (i.e., less memory) than classes, but
  they offer less functionality.
• Primary data types such as Boolean Integer,
  Single, and Double are all structures
• Note that the String data type is a class though

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3. Namespace Structures
Private mcolCurrent As System.Drawing.Color
  mcolCurrent System.Drawing.Color.Navy
 
Allocate memory for the variable
Store the value Navy directly in the variable
variable mcolCurrent Navy
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Chapter Summary

• CAP 211 gives an introduction to how to develop
  .NET software with Visual Basic .NET.

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Lecture Resources

• http//en.wikipedia.org/wiki/.NET_Framework
• http//www.hitmill.com/programming/vbnet/about_vbn
  et.html
• http//www.devarticles.com/c/a/ADO.NET/Introductio
  n-to-.NET/
• http//www.devhood.com/training_modules/dist-a/Int
  ro.NET/?module_id1
• http//homepages.com.pk/kashman/dotnet.htm
• http//www.devhood.com/training_modules/dist-a/Int
  ro.NET/Intro.NET_pres_files/frame.htm

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SELF-REVIEW EXERCISES

• Fill in the blank
• Programs that translate high-level language
  programs into machine language are called
  _______________
• 2. True or False
• Visual Basic .NET is the only language available
  for programming .NET applications.
• Computers can directly understand high-level
  languages.

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SELF-REVIEW EXERCISES

• 3. What is the meaning of the following
  terminologies
• MSIL
• ADO .NET
• ASP .NET
• Portability
• Inter-operability
• 4. What does BASIC in Visual BASIC Stands for?
• 5. How many levels of compilation happen in .NET
  Framework?
• 6. Where can you find COMException class?

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Integrated Development Environment (IDE)

• In computing, an integrated development
  environment (IDE) is a software application that
  provides comprehensive facilities to computer
  programmers for software development.
• An IDE normally consists of a source code editor,
  a compiler and/or interpreter, build automation
  tools, and (usually) a debugger.

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