Introduction to Visual Basic - Electronic Commerce - Lecture Slides, Slides of Fundamentals of E-Commerce

Download Introduction to Visual Basic - Electronic Commerce - Lecture Slides and more Slides Fundamentals of E-Commerce in PDF only on Docsity!

Introduction to Visual Basic and

the VB Integrated Development

Environment

Docsity.com

Learning Objectives

• To describe the .NET framework
• Use the VB IDE to create Windows applications
• Understand the fundamentals of the VB programming language
• Use VB’s decision and looping structures
• Work with the IDE debugging features

Integrated Development Environment

(IDE) (cont’d)

• IDE supports various programming languages
• Example - VS 2005 IDE supports multiple languages
  • C# (C-Sharp)
  • J# (J-Sharp)
  • C++
  • Visual Basic (VB)

.NET Framework

• Provides the foundation for .NET applications
• Primary components
  • Common Language Runtime (CLR)
  • Framework Class Libraries (FCL)
• Common Language Runtime (CLR)
  • Environment that provides services to manage application execution, regardless of the development programming language

The Common Language Runtime (CLR)

• Environment that provides services to manage application execution, regardless of the development programming language
• Provides the execution engine for .NET framework applications
• Ensures that programs are reliable and do not harm other applications

Common Language Runtime - Services

• Loading and executing an application’s code
• Isolating application memory to prevent one application from harming another
• Converting Microsoft Intermediate Language code to native code
• Enforcing code access security
• Handling exceptions
• Supporting debugging

Common Language Runtime -

Terms

• Source code
  • Commands of the program written in any language by the user
• Compiler
  • Program that decodes instructions written in a higher-level language and produces instructions in a lower-level language such as assembly language

Common Language Runtime –

Terms (cont’d)

• MS Intermediate Language (MSIL) code
  • Hardware-independent set of instructions that can be efficiently converted to native binary code to run on a specific hardware platform
  • MSIL code file has an .exe or .dll file extension
• Executable file
  • A file with an .exe extension
  • Can directly run on a computer

Assembly

• A .NET source code is compiled into an .exe or .dll

MSIL file

• Contains MSIL code, as well as program configuration

information about content, versioning, and dependencies on other programs

• Makes applications more reliable and easier to

deploy

Registry

• Hierarchical database that stores system and

program configuration information

• Every workstation that runs the Microsoft

Windows operating system contains a registry

• Registry is difficult to configure and repair
• .NET applications do not rely on registry

JIT Compiler - Steps

• Compiles an assembly when user runs for the first time
• The executable code is cached, or stored, on the target computer in either NAC or GAC
• Native Assembly Cache (NAC)
  • Stores stand-alone executable programs
• Global Assembly Cache (GAC)
  • Stores programs that multiple applications share

Framework Class Libraries

• Libraries that contain code assisting with common programming tasks
• Namespace
  • Naming scheme that uses a hierarchical dotted naming convention to provide a hierarchical, folder-like organization for FCL classes
  • Example System.Windows.Forms – To create graphical user interfaces

Components of IDE

• Document window
  • Main window that displays the Start Page
• Toolbox tab
  • Allows user to access tools to create application items such as command buttons and lists
• Solution Explorer window
  • Displays user’s solutions and their components hierarchically

Components of IDE (cont’d)

• Project
  • Collection of files that comprise an application
  • A project contains one or more forms
• Forms
  • Objects containing the application items with which a user interacts, such as text boxes, buttons, and labels, along with the code to make these items functional
• Solution
  • Made up of one or more projects