10-05-2013, 04:53 PM
Introduction to .NET Framework
Introduction to .NET.ppt (Size: 71.5 KB / Downloads: 37)
What Is .NET
.Net is a new framework for developing windows-based and web-based applications within the Microsoft environment.
The framework offers a new set of software development tools that are superior to the old tools.
The framework offers a fundamental shift in Microsoft strategy: it moves application development from client-centric to server-centric.
Common Language Runtime (CLR)
CLR works like a virtual machine in executing all languages. Currently it supports two:
C# is the new version of C++ containing all features of Java.
VB.NET is the new version of VB containing full object orientation and equal in power to C#.
All .NET languages must obey the rules and standards imposed by CLR. Examples:
Object declaration, creation and use
Data types,language libraries
Error and exception handling
Interactive Development Environment (IDE)
Intermediate Language (IL)
.NET languages are not compiled to machine code. They are compiled to an Intermediate Language (IL).
CLR accepts the IL code and recompiles it to machine code. The recompilation is just-in-time (JIT) meaning it is done as soon as a function or subroutine is called.
The JIT code stays in memory for subsequent calls. In cases where there is not enough memory it is discarded thus making JIT process interpretive.
.NET Class Library
In traditional environments different categories of services are provided to the programmer via libraries such as: C run time library, Win32 APIs, I/O and database access libraries, statistical libraries, etc.
These libraries are language dependent, operating system dependent, and often contain simple subroutine calls as opposed to self describing types.
In .NET all services fall into a single, hierarchy organized, language independent Class Library.
Visual Basic and WebForms
In a manner similar to drawing a WinForm, the VB programmer can now draw a WebForm (I.e., a Web Page)and attach event handlers to it.
WinForm controls such as Text, Image, and Anchor are similar to WinForm controls.
A Web page, just like a form, is a class with its own methods, properties and events. It can be inherited by other Web pages.
VB can thus be used to develop Web-based applications.
Server-Side Processing
A server-side control can detect a user event (e.g., a mouse click) and execute a server-side script that contains the code (the event handler) to handle that event.
The event is generated on the client-side but handled on the server-side.
The event handler typically changes the properties and calls the methods of various controls on the ASP.NET page.
At the termination of the event handler a new HTML page is posted back to the Browser.