03-09-2012, 01:11 PM
ASP.NET Bible
ASP.NETBible.pdf (Size: 7.29 MB / Downloads: 238)
Understanding the .NET Framework
Overview
The Internet revolution of the late 1990s represented a dramatic shift in the way
individuals and organizations communicate with each other. Traditional applications,
such as word processors and accounting packages, are modeled as stand-alone
applications: they offer users the capability to perform tasks using data stored on the
system the application resides and executes on. Most new software, in contrast, is
modeled based on a distributed computing model where applications collaborate to
provide services and expose functionality to each other. As a result, the primary role of
most new software is changing into supporting information exchange (through Web
servers and browsers), collaboration (through e-mail and instant messaging), and
individual expression (through Web logs, also known as Blogs, and e-zines — Web
based magazines). Essentially, the basic role of software is changing from providing
discrete functionality to providing services.
Direct support for security
Developing an application that resides on a user's desktop system and uses local
resources is easy, from a security point of view, because security simply isn't a
consideration in this scenario. Security becomes much more important when you create
applications that access data on remote systems or applications that perform privileged
tasks on behalf of nonprivileged users, because systems may have to authenticate
users, and encryption (scrambling to avoid eavesdropping) may be necessary to secure
data communications.
Windows NT, Windows 2000, and Windows XP have a number of security features
based on Access Control Lists (ACLs). An ACL contains a number of entries that specify
which users may access, or are explicitly denied access, to resources such as files and
printers. ACLs are a great way of protecting executable files (applications) from
unauthorized access, but they do not secure all parts of the file. The .NET Framework
enables both developers and system administrators to specify method-level security.
Developers (through easy-to-use programming language constructs called attributes)
and systems administrators (by using administrative tools and byediting an application's
configuration file) can configure an application's security so that only authorized users
can invoke a component's methods.
Simplified development efforts
Two aspects of creating Web-based applications present unique challenges to Web
developers: visual page design and debugging applications. Visual page design is
straightforward when creating static content; however, when you need to present the
result of executing a query in a tabular format using an ASP page, page design can get
rather involved. This is because developers need to mix traditional ASP code, which
represents the application's logic, and HTML, which represents the presentation of the
data. ASP.NET and the .NET Framework simplify development by allowing developers to
separate an application's logic from its presentation, resulting in an easier-to-maintain
code base.