VISUAL C

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VISUAL C

• Introduction

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What is Visual C?

• It is a very powerful object-oriented language.
• It is based on Microsoft.Net technology.
• It is intuitive, simple, elegant, and powerful.
• It is platform-independent.
• It is supported by Microsoft Visual Studio 7.0.

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.NET Framework

• .NET (dot-net) is the name Microsoft gives to its
  general vision of the future of computing, the
  view being of a world in which many applications
  run in a distributed manner across the Internet.
• We can identify a number of different motivations
  driving this vision
• Firstly, distributed computing is rather like
  object oriented programming, in that it
  encourages specialised code to be collected in
  one place, rather than copied redundantly in lots
  of places. There are thus potential efficiency
  gains to be made in moving to the distributed
  model.

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.NET Framework

• Secondly, by collecting specialised code in one
  place and opening up a generally accessible
  interface to it, different types of machines
  (phones, handhelds, desktops, etc.) can all be
  supported with the same code. Hence Microsoft's
  'run-anywhere' aspiration.
• Thirdly, by controlling real-time access to some
  of the distributed nodes (especially those
  concerning authentication), companies like
  Microsoft can control more easily the running of
  its applications. It moves applications further
  into the area of 'services provided' rather than
  'objects owned'.

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.NET Framework

• Interestingly, in taking on the .NET vision,
  Microsoft seems to have given up some of its
  proprietary tendencies (whereby all the
  technology it touched was warped towards its
  Windows operating system). Because it sees its
  future as providing software services in
  distributed applications, the .NET framework has
  been written so that applications on other
  platforms will be able to access these services.
  For example, .NET has been built upon open
  standard technologies like XML and SOAP.
• At the development end of the .NET vision is the
  .NET Framework. This contains the Common Language
  Runtime, the .NET Framework Classes, and
  higher-level features like ASP.NET (the next
  generation of Active Server Pages technologies)
  and WinForms (for developing desktop
  applications).

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.NET Framework

• The Common Language Runtime (CLR) manages the
  execution of code compiled for the .NET platform.
  The CLR has two interesting features. Firstly,
  its specification has been opened up so that it
  can be ported to non-Windows platforms. Secondly,
  any number of different languages can be used to
  manipulate the .NET framework classes, and the
  CLR will support them. This has led one
  commentator to claim that under .NET the language
  one uses is a 'lifestyle choice'.
• Not all of the supported languages fit entirely
  neatly into the .NET framework, however (in some
  cases the fit has been somewhat Procrustean). But
  the one language that is guaranteed to fit in
  perfectly is C. This new language, a successor
  to C, has been released in conjunction with the
  .NET framework, and is likely to be the language
  of choice for many developers working on .NET
  applications.

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.NET Framework

• The .NET Framework, made up of the Common
  Language Runtime (CLR), the .NET Framework Class
  Library, .NET languages, and Visual Studio .NET,
  supports multiple languages, which allows for
  cross-platform applications.

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.NET Framework

• In order for this to work, a common element must
  exist through all .NET languages. The Common
  Language Specification (CLS) is an agreement that
  encompasses the rules, or specifications, of .NET
  languages. To be considered a .NET language, a
  language must comply with specifications set in
  the CLS agreement. Microsoft provides four
  CLS-compliant languages, including Visual Basic
  .NET, Visual C .NET, Visual C with managed
  extensions, and Jscript. The goals of the CLR
  are
• Simplified application development
• Multiple programming language support
• Good performance and scalability
• A safe and reliable execution environment
• Simplified deployment

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.NET Framework

• The CLR consists of an execution engine, a
  garbage collector, just-in-time (JIT) compiler, a
  security system, and the .NET Framework
  fundamentals.
• All of the CLS-compliant -- or .NET -- languages,
  have managed code compilers that generate
  Microsoft Intermediate Language (MSIL). MSIL is
  machine-independent and can offer benefits
  including just-in-time compilation, metadata, and
  more.
• All .NET applications are constructed from
  Assemblies, a compiled (and versioned) collection
  of code and metadata that forms a functional
  unit. All Assemblies contain information stored
  in something called a Manifest, which contains
  the Assembly name, version, dependencies,
  associated files, and exported features for more
  informative versioning.

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.NET Framework

• Another feature of Microsoft .NET technology that
  directly relates to C is the .NET Framework
  Class Library. This library consists of more than
  2,500 classes whose functionality you can access
  from all of the .NET languages.
• The library is made up of four main parts
• Base Class Library (networking, security,
  diagnostics, file I/O, and OS services)
• Data and SML classes
• Windows user interface
• Web services and Web user interface

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.NET Reliability

• Many users are skeptical about the new .NET
  technology and want to know how .NET technology
  is improving Windows stability and Visual Studio
  reliability. In the past, it was quite difficult
  to manage a Windows PC because of the complexity
  of the applications.
• The introduction of shared DLLs and the ability
  to overwrite DLLs increased this difficulty. In
  addition, unclean uninstallations and associated,
  shared files caused headaches in the removal and
  inclusion of applications.
• Many of these activities caused an unstable PC
  and potentially resulted in a reinstall of the
  operating system.

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.NET Reliability

• Microsoft addressed many of these reliability and
  stability issues with .NET technology.
• Applications no longer rely on the registry
  information, removing registry-related headaches.
  In the .NET Framework, applications are
  self-describing and allow developers to run
  different versions of a DLL on the same machine,
  side by side.
• In addition, rather than the operating system,
  the CLR executes languages that produce managed
  code. Because of this, the CLR can perform many
  safety checks such as memory management, garbage
  collection, and type safety.
• This layer adds a level to the programming
  platform, and this higher abstraction brings more
  safety and security. This results in more
  consistency because all languages use a similar
  class library which in turn enables multiple
  language interoperability.

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C

• C is an object-oriented language that enables
  programmers to develop applications with the
  power of C and the ease of Visual Basic.
• Microsoft built C from the ground up with the
  .NET framework and Object Oriented Programming
  (OOP) in mind. However, C expands OOP even
  beyond Visual C concepts. It is a strongly
  typed language in which everything is an object.
• The core features of C were derived from C-like
  languages. Therefore, if you have experience with
  C, C, or Java, you will have a head start in C
  development.

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C versus Java

• C and Java are both new-generation languages
  descended from a line including C and C. Each
  includes advanced features, like garbage
  collection, which remove some of the low level
  maintenance tasks from the programmer. In a lot
  of areas they are syntactically similar.
• Both C and Java compile initially to an
  intermediate language C to Microsoft
  Intermediate Language (MSIL), and Java to Java
  bytecode. In each case the intermediate language
  can be run - by interpretation or just-in-time
  compilation - on an appropriate 'virtual
  machine'. In C, however, more support is given
  for the further compilation of the intermediate
  language code into native code.

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C versus Java

• C contains more primitive data types than Java,
  and also allows more extension to the value
  types. For example, C supports 'enumerations',
  type-safe value types which are limited to a
  defined set of constant variables, and 'structs',
  which are user-defined value types.
• Unlike Java, C has the useful feature that we
  can overload various operators.
• Like Java, C gives up on multiple class
  inheritance in favour of a single inheritance
  model extended by the multiple inheritance of
  interfaces.
• C also uses 'delegates' - type-safe method
  pointers. These are used to implement
  event-handling.
• In Java, multi-dimensional arrays are implemented
  solely with single-dimensional arrays where
  arrays can be members of other arrays. C
  implements genuine rectangular arrays.