Introduction to VB.Net

Visual Basic.Net

VB.Net is a simple, modern, object-oriented computer programming language developed by Microsoft to combine the power of the .NET Framework and the common language runtime with the productivity benefits that are the hallmark of Visual Basic.

Visual Basic .NET is one of the two flagship languages (with C#) for the .NET framework from Microsoft. Despite being called Visual Basic, it is actually not backwards-compatible with VB6, and any code written in the old version will not compile under VB.NET.

As a language, Visual Basic.NET has the following traits:

Object-Oriented

As with all .NET languages, VB.NET includes full-blown support for object-oriented concepts, including simple inheritance. Everything in VB.NET is an object, including all of the primitives (Short, Integer, Long, String, Boolean, etc.) as well as types, events, and even assemblies. Everything inherits from the Object base class.

Event-Driven

All previous versions of Visual Basic were event-driven, but this feature is heavily enhanced under the .NET framework. Events are no longer recognized because they use a certain naming convention (ObjectName_EventName), but now are declared with a Handles ObjectName.EventName clause. Event handlers can also be declared at runtime using the AddHandler command.

.NET Framework

As the name implies, VB.NET runs on top of Microsoft's .NET framework, meaning the language has full access to all of the supporting classes in the framework. It's also possible to run VB.NET programs on top of Mono, the open-source alternative to .NET, not only under Windows, but even Linux or Mac OSX.

HISTORY

Visual Basic was initially introduced in 1991 as the first programming language that directly supported programmable graphical user interfaces using language-supplied objects. From that time until 2002, there were five other versions released, each version having features that increased the power of the language. In 2001, Microsoft released the .NET (pronounced “dot net”) platform. Visual Basic .NET, or VB.NET, is an upgrade to the last version of VB (version 6.0) that conforms to the .NET platform. As you will see in subsequent chapters, the changes in VB.NET allow programmers to write Web or desktop applications within the same language. In addition, VB.NET is fully object-oriented as opposed to prior versions that had many, but not all, of the elements of an object-oriented language. This book is based on VB.NET. In the balance of the book we will sometimes refer to Visual Basic as VB, omitting .NET.

 

The following reasons make VB.Net a widely used professional language:

·         Modern, general purpose.

·         Object oriented.

·         Component oriented.

·         Easy to learn.

·         Structured language.

·         It produces efficient programs.

·         It can be compiled on a variety of computer platforms.

·         Part of .Net Framework.

Strong Programming Features VB.Net

VB.Net has numerous strong programming features that make it endearing to multitude of programmers worldwide. Let us mention some of these features:

·         Boolean Conditions

·         Automatic Garbage Collection

·         Standard Library

·         Assembly Versioning

·         Properties and Events

·         Delegates and Events Management

·         Easy to use Generics

·         Indexers

·         Conditional Compilation

·         Simple Multithreading