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Visual Basic .NET
Vb dot net.png
Usual file extensions .vb
Paradigm structured, imperative, object-oriented, declarative
Appeared in 2001 (last revised 2008)
Designed by Microsoft
Developer Microsoft
Stable release Visual Basic 2008 (VB 9.0) (November 19, 2007)
Typing discipline dynamic, strong, both safe and unsafe[1], nominative
Major implementations .NET Framework, Mono
Dialects Microsoft Visual Studio .NET, .NET 2003, 2005, 2008,2010(Beta)
OS Microsoft Windows
License CLR Proprietary
Website Microsoft's VB.NET website

Visual Basic .NET (VB.NET) is an object-oriented computer programming language that can be viewed as an evolution of Microsoft's Visual Basic (VB) which is generally implemented on the Microsoft .NET Framework. Microsoft currently supplies Visual Basic Express Edition free of charge.

Contents

Versions of Visual Basic .NET

As of November 2007, there are four versions of Visual Basic .NET that were implemented by The Visual Basic Team

Visual Basic .NET (VB 7)

The original Visual Basic .NET was released alongside Visual C# and ASP.NET in 2002. Significant changes broke backward compatibility with older versions and caused a rift within the developer community[2].

Visual Basic .NET 2003 (VB 7.1)

Visual Basic .NET 2003 was released with version 1.1 of the .NET Framework. New features included support for the .NET Compact Framework and a better VB upgrade wizard. Improvements were also made to the performance and reliability of the .NET IDE (particularly the background compiler) and runtime. In addition, Visual Basic .NET 2003 was available in the Visual Studio .NET 2003 Academic Edition (VS03AE). VS03AE is distributed to a certain number of scholars from each country without cost.

Visual Basic 2005 (VB 8.0)

Visual Basic 2005 is the name used to refer to the update to Visual Basic .NET, Microsoft having decided to drop the .NET portion of the title.

For this release, Microsoft added many features, including:

  • Edit and Continue
  • Design-time expression evaluation.
  • The My pseudo-namespace (overview, details), which provides:
    • easy access to certain areas of the .NET Framework that otherwise require significant code to access
    • dynamically-generated classes (notably My.Forms)
  • Improvements to the VB-to-VB.NET converter [3]
  • The Using keyword, simplifying the use of objects that require the Dispose pattern to free resources
  • Just My Code, which hides boilerplate code written by the Visual Studio .NET IDE
  • Data Source binding, easing database client/server development

The above functions (particularly My) are intended to reinforce Visual Basic .NET's focus as a rapid application development platform and further differentiate it from C#.

Visual Basic 2005 introduced features meant to fill in the gaps between itself and other "more powerful" .NET languages, adding:

'IsNot' operator patented

One other feature of Visual Basic 2005 is the IsNot operator that makes 'If X IsNot Y' equivalent to 'If Not X Is Y', which gained notoriety[6] when it was found to be the subject of a Microsoft patent application.[7][8]

Visual Basic 2005 Express

Part of the Visual Studio product range, Microsoft created a set of free development environments for hobbyists and novices, the Visual Studio 2005 Express series. One edition in the series is Visual Basic 2005 Express Edition, which was succeeded by Visual Basic 2008 Express Edition in the 2008 edition of Visual Studio Express.[9]

The Express Editions are targeted specifically for people learning a language. They have a streamlined version of the user interface, and lack more advanced features of the standard versions. On the other hand, Visual Basic 2005 Express Edition does contain the Visual Basic 6.0 converter, so it is a way to evaluate feasibility of conversion from older versions of Visual Basic.

Visual Basic 2008 (VB 9.0)

Visual Basic 9.0 was released together with the Microsoft .NET Framework 3.5 on November 19, 2007.

For this release, Microsoft added many features, including:

Visual Basic 'VBx' (VB 10.0)

In 2007, Microsoft planned to use the Dynamic Language Runtime (DLR) for the upcoming Visual Basic 10, also known as VBx[10]. However, as of August 2009, no further mention of VBx working on the DLR has been made by Microsoft on development updates. Similar to C#, Visual Basic will be able to access objects from dynamic languages built on the DLR such as IronPython and IronRuby[11]

Relation to older versions of Visual Basic (VB6 and previous)

Whether Visual Basic .NET should be considered as just another version of Visual Basic or a completely different language is a topic of debate. This is not obvious, as once the methods that have been moved around and that can be automatically converted are accounted for, the basic syntax of the language has not seen many "breaking" changes, just additions to support new features like structured exception handling and short-circuited expressions. Two important data type changes occurred with the move to VB.NET. Compared to VB6, the Integer data type has been doubled in length from 16 bits to 32 bits, and the Long data type has been doubled in length from 32 bits to 64 bits. This is true for all versions of VB.NET. A 16-bit integer in all versions of VB.NET is now known as a Short. Similarly, the Windows Forms GUI editor is very similar in style and function to the Visual Basic form editor.

The version numbers used for the new Visual Basic (7, 7.1, 8, 9, ...) clearly imply that it is viewed by Microsoft as still essentially the same product as the old Visual Basic.

The things that have changed significantly are the semantics—from those of an object-based programming language running on a deterministic, reference-counted  engine based on COM to a fully object-oriented language backed by the .NET Framework, which consists of a combination of the Common Language Runtime (a virtual machine using generational garbage collection and a just-in-time compilation engine) and a far larger class library. The increased breadth of the latter is also a problem that VB developers have to deal with when coming to the language, although this is somewhat addressed by the My feature in Visual Studio 2005.

The changes have altered many underlying assumptions about the "right" thing to do with respect to performance and maintainability. Some functions and libraries no longer exist; others are available, but not as efficient as the "native" .NET alternatives. Even if they compile, most converted VB6 applications will require some level of refactoring to take full advantage of the new language. Documentation is available to cover changes in the syntax, debugging applications, deployment and terminology.[12]

Comparative samples

The following simple example demonstrates similarity in syntax between VB and VB.NET. Both examples pop up a message box saying "Hello, World" with an OK button.

Classic VB example:

Private Sub Command1_Click()
    MsgBox "Hello, World"
End Sub

A VB.NET example, MsgBox or the MessageBox class can be used:

Public Class Form1
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        MsgBox("Hello, World")
    End Sub
End Class
Public Class Form1
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        MessageBox.Show("Hello, World")
    End Sub
End Class
  • Both Visual Basic 6 and Visual Basic .NET will automatically generate the Sub and End Sub statements when the corresponding button is clicked in design view. Visual Basic .NET will also generate the necessary Class and End Class statements. The developer need only add the statement to display the "Hello, World" message box.
  • Note that all procedure calls must be made with parentheses in VB.NET, whereas in VB6 there were different conventions for functions (parentheses required) and subs (no parentheses allowed, unless called using the keyword Call).
  • Also note that the names Command1 and Button1 are not obligatory. However, these are default names for a command button in VB6 and VB.NET respectively.
  • In VB.NET, the Handles keyword is used to make the sub Button1_Click a handler for the Click event of the object Button1. In VB6, event handler subs must have a specific name consisting of the object's name ("Command1"), an underscore ("_"), and the event's name ("Click", hence "Command1_Click").
  • There is a function called MsgBox in the Microsoft.VisualBasic namespace which can be used similarly to the corresponding function in VB6. There is a controversy about which function to use as a best practice (not only restricted to showing message boxes but also regarding other features of the Microsoft.VisualBasic namespace). Some programmers prefer to do things "the .NET way", since the Framework classes have more features and are less language-specific. Others argue that using language-specific features makes code more readable (for example, using int (C#) or Integer (VB.NET) instead of System.Int32).
  • In VB 2008, the inclusion of "Byval sender as Object, Byval e as EventArgs" has become optional.

The following example demonstrates a difference between VB6 and VB.NET. Both examples close the active window.

Classic VB Example:

Sub cmdClose_Click()
    Unload Me
End Sub

A VB.NET example:

Sub btnClose_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnClose.Click
    Me.Close()
End Sub

Note the 'cmd' prefix being replaced with the 'btn' prefix, conforming to the new convention previously mentioned.

Visual Basic 6 did not provide common operator shortcuts. The following are equivalent:

VB6 Example:

Sub Timer1_Timer()
    Me.Height = Me.Height - 1
End Sub

VB.NET example:

Sub Timer1_Tick(ByVal sender As Object, ByVal e As EventArgs) Handles Timer1.Tick
    Me.Height -= 1
End Sub

Criticism

Long-time Visual Basic users have complained [13] about Visual Basic .NET because initial versions dropped a large number of language constructs and user interface features [14] that were available in VB6 (which is no longer sold by Microsoft now), and changed the semantics of those that remained; for example, in VB.NET parameters are (by default) passed by value, not by reference. Detractors refer pejoratively to VB.NET as Visual Fred or DOTNOT.[15] On March 8, 2005, a petition [16] was set up in response to Microsoft's refusal to extend its mainstream support[17] for VB6.

VB.NET's supporters state that the new language is in most respects more powerful than the original, incorporating modern object oriented programming paradigms in a more natural, coherent and complete manner than was possible with earlier versions. Opponents tend to respond that although VB6 has flaws in its object model, the cost in terms of redevelopment effort is too high for any benefits that might be gained by converting to VB.NET.[citation needed]

It is simpler to decompile languages that target Common Intermediate Language (CIL), including VB.NET, compared to languages that compile to machine code. Tools such as .NET Reflector can provide a close approximation to the original code due to the large amount of metadata provided in CIL.[citation needed]

Microsoft supplies an automated VB6-to-VB.NET converter with Visual Studio .NET, which has improved over time, but it cannot convert all code, and almost all non-trivial programs will need some manual effort to compile. Most will need a significant level of code refactoring to work optimally. Visual Basic programs that are mainly algorithmic in nature can be migrated with few difficulties; those that rely heavily on such features as database support, graphics, unmanaged operations or on implementation details are more troublesome.[citation needed]

In addition, the required runtime libraries for VB6 programs are provided with Windows 98 SE and above, while VB.NET programs require the installation of the significantly larger .NET Framework. The framework is included with Windows 7, Windows Vista, Windows XP Media Center Edition, Windows XP Tablet PC Edition, Windows Server 2008 and Windows Server 2003. For other supported operating systems such as Windows 2000 or Windows XP (Home or Professional Editions), it must be separately installed.

Microsoft's response to developer dissatisfaction has focused around making it easier to move new development and shift existing codebases from VB6 to VB.NET. Their latest offering is the VBRun website, which offers code samples and articles for:

  • Using VB.NET to complete tasks that were common in VB6, like creating a print preview
  • Integrating VB6 and VB.NET solutions (dubbed VB Fusion)

Cross-platform and open-source development

The creation of open-source tools for VB.NET development have been slow compared to C#, although the Mono development platform provides an implementation of VB.NET-specific libraries and a VB.NET 8.0 compatible compiler written in VB.NET[18], as well as standard framework libraries such as Windows Forms GUI library.

SharpDevelop and MonoDevelop are open-source alternative IDEs.

Hello world example

The following is a very simple VB.NET program, a version of the classic "Hello world" example created as a console application:

Module Module1
 
    Sub Main()
        Console.WriteLine("Hello, world!")
    End Sub
 
End Module

The effect is to write the text Hello, world! to the command line. Each line serves a specific purpose, as follows:

Module Module1

This is a module definition, a division of code similar to a class, although modules can contain classes. Modules serve as containers of code that can be referenced from other parts of a program.[19]
It is common practice for a module and the code file, which contains it, to have the same name; however, this is not required, as a single code file may contain more than one module and/or class definition.

Sub Main()

This is the entry point where the program begins execution.[20] Sub is an abbreviation of "subroutine."

Console.WriteLine("Hello, world!")

This line performs the actual task of writing the output. Console is a system object, representing a command-line console and granting programmatic access to the operating system's standard streams. The program calls the Console method WriteLine, which causes the string passed to it to be displayed on the console. Another common method is using MsgBox (a Message Box).[21]

Notes

  1. ^ Option Strict can be used to switch between safe and unsafe type checking.
  2. ^ "Petition to Microsoft". Classicvb.org. 8 March 2005. http://www.classicvb.org/petition/. Retrieved 16 June 2009. 
  3. ^ What's New with the Visual Basic Upgrade Wizard in Visual Basic 2005
  4. ^ Defining and Using Generics in Visual Basic 2005
  5. ^ Operator Overloading in Visual Basic 2005
  6. ^ Sherriff, Lucy (22 February 2005). "Real Software slams MS IsNot patent application". The Register. http://www.theregister.co.uk/2005/02/22/real_slams_ms_patent/. Retrieved 6 April 2009. 
  7. ^ Taft, Darryl K. (21 February 2005). "Real Software Slams Microsofts Patent Effort". eWeek. http://www.eweek.com/article2/0,1759,1766949,00.asp. Retrieved 6 April 2009. 
  8. ^ Vick, Paul A. Jr.; Barsan, Costica Corneliu; Silver, Amanda K. (14 May 2003). "United States Patent Application: 20040230959". IS NOT OPERATOR. US Patent & Trademark Office. http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220040230959%22.PGNR.&OS=DN/20040230959&RS=DN/20040230959. Retrieved 6 April 2009. 
  9. ^ Microsoft Brings Programming to the Masses With Visual Studio Express: Company brings the power of code to growing community of hobbyist programmers who seek to integrate technology and software into their everyday lives
  10. ^ "What the heck is "VBx"?". 1 May 2007. http://www.panopticoncentral.net/archive/2007/05/01/20383.aspx. Retrieved 12 August 2009. "With the new DLR, we have support for IronPython, IronRuby, Javascript, and the new dynamic VBx compile" 
  11. ^ "What's New in Visual Basic 2010". Microsoft. 2009. http://msdn.microsoft.com/en-us/library/we86c8x2%28VS.100%29.aspx. Retrieved 12 August 2009. "Visual Basic binds to objects from dynamic languages such as IronPython and IronRuby" 
  12. ^ Migration - Upgrading from Visual Basic 6.0 MSDN – Developer Center – Visual Basic 6.0 Resource Center – Migration –
  13. ^ Karl E. Peterson. "Microsoft Basic: 1976-2001,R.I.P.". http://vb.mvps.org. http://vb.mvps.org/vfred/Trust.asp. Retrieved 7 March 2009. 
  14. ^ Microsoft Basic: 1976-2001, R.I.P
  15. ^ Microsoft Basic: 1976-2001, R.I.P
  16. ^ Petition to Microsoft
  17. ^ Product Family Life-Cycle Guidelines for Visual Basic 6.0
  18. ^ Mono Project: VisualBasic.NET support
  19. ^ "Module Statement". MSDN - Developer Center. http://msdn.microsoft.com/en-us/library/aaxss7da(VS.80).aspx. Retrieved 20 January 2010. 
  20. ^ "Main Procedure in Visual Basic". MSDN - Developer Center. http://msdn.microsoft.com/en-us/library/ms235406(VS.80).aspx. Retrieved 20 January 2010. 
  21. ^ "Visual Basic Version of Hello, World". MSDN - Developer Center. http://msdn.microsoft.com/en-us/library/3cf7t4xt(VS.80).aspx. Retrieved 20 January 2010. 

See also

External links

Tutorials


Wikibooks

Up to date as of January 23, 2010

From Wikibooks, the open-content textbooks collection


Visual Basic .NET is a multi-purpose computer programming language from Microsoft that is suitable for most development needs. The language is designed with Rapid Application Development in mind, providing several tools to shorten development time. This WikiBook introduces Visual Basic.NET language fundamentals and covers a variety of the base class libraries (BCL) provided by the .NET Framework.

Contents

Introduction

IntroductionDevelopment stage: 100% (as of Oct 30, 2005) 
A description of Visual Basic .NET.
The Visual Studio Integrated Development Environment (IDE)Development stage: 25% (as of Mar 14, 2006) 
A Microsoft application to simplify application development.
Getting StartedDevelopment stage: 100% (as of Oct 30, 2005) 
Making your first application.

Language Basics

Basic syntax 
Describes the basics in how the applications you write will be interpreted.
VariablesDevelopment stage: 75% (as of Dec 28, 2005) 
The entities used to store various types of data.
ArraysDevelopment stage: 25% (as of Oct 30, 2005) 
A variable that stores several data of the same data type.
Branch statements 
The various conditional statements in the language for selective code execution.
Loop statementsDevelopment stage: 25% (as of Oct 6, 2007) 
The various loop statements in the language for repetitive code execution.

Operators

Operators in generalDevelopment stage: 25% (as of Oct 30, 2005) 
What are operators in a programming language.
Assignation and comparison operators 
Describes the '=', 'Is' and 'IsNot' operators.
Arithmetic operators 
Describes the operators that work on numerical values, such as the '+' in addition.
String and character operators 
Describes the operators used for string and character manipulation, such as the '&' and '+' operators.
Logical operators 
Describes the operators used in boolean logic, such as the 'And' and 'Or' operators.
Binary operators 
Describes the operators used in maniputating in binary, such as the 'And' and '<<' operators.

Windows Programming

ControlsDevelopment stage: 25% (as of Mar 8, 2006) 
The windows controls, such as the button and text boxes.
Components 
Objects that can be added at design time using the Window Designer, but is not visible at runtime, such as the Timer component.
Interprocess Communication 
How programs can communicate with each other across application boundaries.

Object Oriented Programming

Basics

Inheritance
Interfaces
Abstract and partial classes
Object Lifetime
Enumerations 
A set of related constants defining a value type.

Classes

Modules 
A special class for exposing shared functions and variables.
Namespaces 
Giving your code its own space to live in.
Classes 
The blueprints of objects that describes how they should work.
Objects 
Cornerstones of any object-oriented programming language, objects are the tools you use to perform work.
Encapsulation and accessor levels 
Explains protection of object states by encapsulation.
The IDisposable Interface

Advanced Data Structure

CollectionsDevelopment stage: 00% (as of Oct 30, 2005) 
Advanced data structure for encapsulating data.

The .NET Framework

The .NET assembly 
All .NET solutions have their components contained in assemblies.
.NET Framework Overview 
An overview of the .NET class library used in VB.NET
The .NET framework 
A language is merely a way of communication. The .NET framework represents the tools at your disposal to get actual work done.
Security 
How security is used in the .NET framework

Graphics

Hello, this is the graphics section, please add information to me.xx

GDI+

GDI+ is a way to draw simple graphics and strings on a Form.

MS Office Automation

Microsoft Office Automation

Manipulating MS Office documents and even MS Office itself from VB.NET

External Links

About this book

Style GuideDevelopment stage: 25% (as of Oct 30, 2005)


Simple English

Visual Basic .NET is the second series of Microsoft's Visual Basic series. It is sometimes shortened to VB.NET. It is an IDE (Integrated Development Environment) and it includes an easy 'drag-and-drop' interface. It can make complete programs for Windows very easily.

Contents

Background

Visual Basic

See also: Visual Basic

It was first released in 1991 by Microsoft. Visual Basic is a simple way to make programs for Windows. It started as Project Ruby by Alan Cooper and then was sold to Microsoft. The system is built loosely on the original BASIC programming language released in 1963 and it can 'Test' programs in real-time, error checking them in a user-friendly way.

.NET Framework

This package is the 'backbone' of Visual Basic .NET. When applications are created, the Windows Installer includes the framework with it. It includes all the items needed to run the VB.NET applications that have been made.

Editions

Visual Basic was first released in May 1991 for Windows. Many versions have been released since then. These are listed below:

Name Operating System Date Released
Visual Basic .NET Windows 2002
Visual Basic .NET 2003 Windows 2003
Visual Basic 2005 Windows 2005
Visual Basic 2005 Studio Windows 2005
Visual Basic 2008 Studio Windows 2008
Visual Basic 2010 Studio Windows 2010

Visual Basic 2010 Express Edition

This is a free version of Visual Basic 2010 released officially from Microsoft. It is aimed at encouraging more newbie programmers to try the series. The program can be downloaded from Microsoft's Website.

Controls

Visual Basic .NET uses many controls which can be added to the forms or windows in the application. Other developers can create controls for applications, not just the ones that Microsoft include.

Examples

The following example makes a program window pop up that says "Hello World" and has a button that says "OK" used to close the window:

Public Sub button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles

   button1.Click
   MsgBox("Hello World")

End Sub

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