Microsoft introduced the .NET Framework in 2000 as a new approach to
software development. The .NET Framework borrowed ideas from the best
practices in the software industry as well as brought new ideas to the
table in an effort to meet developer needs and requests.
Virtually all programming languages manage data at some point. The
primary reason that communication between applications created using
C++, Visual Basic, Visual FoxPro, and other languages was difficult was
because each language stored data being managed in a unique set of data
types. For example, an integer in one language may not represent an
integer in another language. Data needed to be converted to common data
types to communicate between languages.
The .NET Framework introduced a common set of data types (the Common
Type System) that is used by all .NET-compliant languages (C++, Visual
Basic, C#, etc). Thus all languages can easily intercommunicate. Furthermore, all .NET-compliant languages render a common result when compiling code, Microsoft Intermediate Language (MSIL).
(see footnote)
MSIL can be deployed to any platform running the Common Language
Runtime (CLR). Currently, the CLR is only available for Microsoft
Windows although an open source version of the CLR was created for Linux
(called the Mono Project).
Code written by using the .NET Framework is compiled instead of
interpreted resulting in much better performance than Java and competing
technologies.
Microsoft took the Web development industry by storm with their .NET
upgrade to ASP. ASP.NET put a new face on Web development through a
compiled code architecture and improved state management and it provides
access to the full functionality of the .NET Framework. ASP.NET is
built around XML, supports the latest Web development standards, and
allows for the creation of advanced Web Services.
The .NET Framework also provides improved data access and database integration through ADO.NET. For more information, see MSDN.
There are many more features and benefits of the .NET Framework than
those mentioned here. The .NET Framework has become the leading
software development environment available.
Introducing Silverlight
What's New in the .NET Framework
As of the writing of this course, version 3.5 of the .NET Framework
has been released. Version 3.5 includes features that encompass all
facets of Windows, Web, and network development:
- Includes just under 10,000 classes, methods, and properties.
- Complies with the latest Web development standards.
- Introduces revolutionary technologies used in Windows Vista development, rich media and user experiences, workflow management, security and authorization, and complete distributed communication protocols.
The .NET Framework can also be fully extended by developers to
create custom classes and types. The functionality of the .NET Framework
spans the server, the workstation, and the Web. The four primary
additions to the .NET Framework as of version 3.0 are:
- Windows Presentation Foundation (WPF)
- Windows Communication Foundation (WCF)
- Windows Workflow Foundation (WF)
- CardSpace
Windows Presentation Foundation (WPF)
WPF is used to develop elaborate user interfaces like those that
adorn Windows Vista and managed advanced media streaming and
integration. WPF is the a complete revamp of Windows Forms so that user
interface, graphic, and media development is now designed around the
.NET Framework.
Windows Communication Foundation (WCF)
WCF encompasses the ASP.NET Web Services and .NET remoting
functionality that was contained in the .NET Framework 2.0 as well as
new communication technologies.
Windows Workflow Foundation (WF)
WF is used to model complex workflow processes.
CardSpace
CardSpace is the embodiment of new security and user authorization functionality.
ASP.NET AJAX
ASP.NET AJAX was developed to improve performance in the browser by
making post backs and calls between the browser and server
asynchronously. ASP.NET AJAX uses new built-in types and controls and
JavaScript.
Both ASP.NET and ASP.NET AJAX are heavily dependent upon the ASP.NET
page event life cycle, are tightly coupled to the server, and have a
tough time competing with advanced, media-rich plug-in solutions such as
Adobe Flash. Additionally, it is difficult to create Web applications
that offer a consistent experience across all supported browsers and
platforms by using ASP.NET and AJAX. In 2006, Microsoft began developing
a solution to extend into the browser and offer media experiences more
robust than competing plug-in solutions.
In 2007, Microsoft introduced Silverlight.
(see footnote)
Silverlight is a free plug-in that encompasses a subset of
functionality from the .NET Framework and WPF. In a manner similar to
the JVM
(see footnote),
Silverlight runs in the browser as a "sandbox" - a secure zone
installed into the browser that accommodates Silverlight functionality
while completely protecting the host platform from any possibly adverse
actions performed by Silverlight.
Silverlight Architecture
Unlike ASP.NET, the bulk of Silverlight processing occurs on the
client machine thus decreasing server resource utilization and improving
the Web experience on the client. The figure below shows the difference
between ASP.NET processing and Silverlight processing:
When a client initially attempts to run a Silverlight application,
if the Silverlight plug-in has not been installed on the client machine,
it will be downloaded and installed. Upon subsequent requests to run
the application, the application will instantiate on the client machine
and make requests for resources from the server only when necessary. The
Silverlight plug-in can be thought of as a scaled-down version of the
full .NET Framework. It only contains those classes and functionality
that are applicable to a Silverlight Web client and those were
streamlined and optimized for use on the Web client machine.
Silverlight was designed using the same design paradigm as ASP.NET.
Each page of a Silverlight application includes an associated code
behind file that includes the code that handles events fired by the
page. Silverlight resembles WPF in that it uses Extensible Application
Markup Language (XAML) to construct the user interface (presentation
layer). As Silverlight applications are composed of text-based files
that include markup and code, they can be created using any text editor;
however, more advanced tools and development environments such as
Visual Studio or Expression Blend simplify the task significantly.
