2. The .NET Platform and its Architecture
.NET Framework (Pronounced as “dot net”) is a software framework
developed by Microsoft that runs primarily on Microsoft windows. It includes
a large class library named as Framework Class Library (FCL) and provides
Language interoperability across several programming languages. Programs
written for .NET Framework execute in a software environment named the
Common Language Runtime (CLR). The CLR is an application virtual
machine that provides services such as security, memory management, and
exception handling. As such, computer code written using .NET Framework is
called “Managed Code”. FCL and CLR together constitute the .NET
Framework.
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3. FCL provides user interface, data access, database connectivity,
cryptography, web application development, numeric algorithms,
and network communications. Programmers produce software by
combining their source code with .NET Framework and other
libraries. The Framework is intended to be used by most new
applications created for the Windows platform. Microsoft also
produces an integrated development environment largely for
.NET software called Visual Studio.
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5. Common Language Infrastructure (CLI): - provides a
language-neutral platform for application development and
execution. By implementing the core aspects of .NET
Framework within the scope of CLI, these functions will not be
tied to one language but will be available across the many
languages supported by the framework.
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6. Common Language Runtime (CLR): - serves as the execution engine of
.NET Framework and offers many services such as memory management,
type safety, exception handling, garbage collection, security and thread
management. All programs written for .NET Framework are executed by the
CLR. Programs written for .NET Framework are complicated into Common
Intermediate Language (CIL) code, as opposed to being directly compiled into
machine code. During execution, an architecture-specific just-in-time (JIT)
compiler turns the CIL code into machine code.
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7. Assemblies: - Compiled CIL code is stored in CLI assemblies.
As mandated by the specification, assemblies are stored in
Portable Executable (PE) file format, common on windows
platform for all Dynamic-Link Library (DIL) and executable
(.exe) files. Assemblies are considered equivalent if they share
the same complete name.
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8. Class Library: - .NET Framework includes an implementation of the CLI
foundational Standard Libraries. The .NET Framework Class Library (FCL) is
organized in a hierarchy of namespaces. These class libraries implement many
common functions, such as file reading and writing, graphic rendering,
database interaction, and XML document manipulation. The class libraries are
available for all CLI complaint languages. The FCL implements the CLI Base
Class Library (BCL) and other class libraries some are specified by CLI and
other are Microsoft specific.
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10. •Design Principles
Interoperability: - because computer systems commonly require interaction
between newer and older applications, .NET Framework provides means to
access functions implemented in newer and older programs that executed
outside .NET environment.
Language Independence: - .NET Framework introduces a Common Type
System (CTS) that defines all possible data types and programming
constructs supported by CLR and how they may or may not interact
conforming to CLI specification. Because of this feature .NET Framework
supports the exchange of types and object instances between libraries and
applications written using any conforming .NET language.
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11. Portability: - while Microsoft has never implemented the full framework on
any system except Microsoft Windows, it has engineered the framework to be
cross-platform, and implementations are available for other operating systems.
Security: - .NET Framework has its own security mechanism with two
general features: Code Access Security (CAS), and validation and
verification. CAS is based on evidence that is associated with a specific
assembly. CAS uses evidence to determine the permissions granted to the
code. The demand causes CLR to perform a call stack walk: every assembly
of each method in the call stack is checked for the permission; if any assembly
is not granted the permission a security exception is thrown.
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12. Memory Management: - CLR frees the developer from the burden of
managing memory; it handles memory management itself be detecting when
memory can be safely freed. As long as a reference to an object exists, which
may be either direct, or via a graph of objects, the object is considered to be in
use. When no reference to an object exists, and it cannot be reached or used, it
becomes garbage, eligible for collection.
Performance: - when an application is first launched, the.NET Framework
compiles the CIL code into executable code using its Just-in-Time compiler,
and caches the executable program into the .NET Native Image Cache. Due to
caching, the application launches faster for subsequent launches, although the
first launch is usually slower. To speed up the first launch, developers may use
the Native Image Generator utility to manually ahead-of-time compile and
cache any .NET application.
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13. The use of .NET Platform in
Application Development
Less Coding and Increased Reuse of Code: - this Framework works on
Object-Oriented programming which eliminates unnecessary codes and
involves less coding for the developers. .NET consists of re-usable code and
many re-usable components. This translates into less time and consequently
less cost to develop applications.
Deployment: - with features such as no-impact applications, private
components, controlled code sharing, side-by-side versioning and partially
trusted code, the .NET Framework makes deployment easier post deployment.
The code execution environment supports safe code execution for reduce
conflicts in software deployment and versioning, and minimized performance
problems of scripted or interpreted environments.
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14. Cont.….
Reliability: - since its release in 2002, .NET has been used to develop
thousands of applications. Its performance on Microsoft Windows Server
2003 and Windows 2000 Server is also very stable and reliable.
Security: - .NET offers enhanced application security as web application
developed using ASP.NET has windows confirmation and configuration.
Managed code and CLR offer safeguard features such as role-based security
and code access security.
Use across Platforms and Languages: - .NET allows developers to develop
applications for a desktop, a browser, a mobile browser, or an application
running on PDA. .NET is promoted as a language-independent Framework,
which implies that development can take place in different compliant
languages.
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15. Cont.….
Use for Service-Oriented Architecture: - .NET is often used
for Web Services, which is a solution for executing an SOA
strategy. Through Web Services, applications which are
designed in different programming languages or platforms are
able to communicate and transmit data utilizing standard
internet protocols.
Integration with Legacy Systems: - the capability of .NET to
process all types of XML documents and writes any format of
file with swiftness and ease provides multiple routes for
integration.
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16. Introduction to Microsoft
Visual Studio 2012
Visual Basic is a third-generation event-driven programming
language first released by Microsoft in 1991. Visual Basic is a
user-friendly programming language designed for beginners.
Therefore, it enables anyone to develop GUI window
applications easily. Visual Basic has gone through many phases
of development since the days of BASIC that was built for DOS.
BASIC stands for Beginners' All-purpose Symbolic Instruction
Code.
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17. Cont.….
Visual Studio has been designed to ensure that developers can
provide a continuous flow of value to the business. The interface
has been revamped to remove significant clutter from the screen,
while still providing fast access to frequently used features.
Removing unnecessary distractions helps developers remain
focused on the key development tasks.
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18. Cont.….
The Visual Studio 2012 start page comprises three sections, the
start page, the output section and the solution explorer. In the
start page, you can start a new project, open a project or open a
recent project. You can also check for the latest news in Visual
Studio 2012 Express for Windows Desktop. The start page also
consists of a menu bar and a tool bar where you can perform
various tasks by clicking the menu items.
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