July 22, 2001Introduction to.NET1 Introduction to.NET Framework Gholamali Semsarzadeh July 2001

July 22, 2001Introduction to.NET2 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.

July 22, 2001Introduction to.NET3 Base Class Library Common Language Specification Common Language Runtime ADO.NET: Data and XML VBVC++VC# Visual Studio.NET ASP.NET: Web Services and Web Forms JScript… Windows Forms Framework, Languages, And Tools

July 22, 2001Introduction to.NET4 Agenda  Common language runtime (CLR) .NET class library  Cross language application development  Tools for developing Windows applications  Tools for developing Web applications

July 22, 2001Introduction to.NET5

July 22, 2001Introduction to.NET6 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.

July 22, 2001Introduction to.NET7 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)

July 22, 2001Introduction to.NET8 Common Language Runtime (CLR) Implication of CLR are wide ranging:  Deep Language Integration  No more “DLL HELL”  Side by side execution  Fewer errors

July 22, 2001Introduction to.NET9 Common Data Types CLR provides a set of primitive types that all languages must support. The data types include:  Integer—three types 16/32/64 bits  Float—two types: 32/64 bits  Boolean and Character  Date/time and Time span The primitive types can be collected into  Arrays  Structures  Combination of the two

July 22, 2001Introduction to.NET10 Common Type System IL is completely object-oriented. It requires everything to be the type of a class, structure or interface. Examples of types:  Integer  String  Rectangle  Customer  Contract  Chart  Recordset  Check  Financial Institution

July 22, 2001Introduction to.NET11 Examples of Types Type Declaration Usage (Properties) Usage (Methods) Dim i As Integeri=100i+1 Dim r As Rectangler.Width*r.Heightr.Area Dim c As Chartc.BackColor=‘red’c.AddSeries (points) Dim r As RecordSetr.Rate*r.HoursR=SqlText Dim c As Checkc.Amount=100c.Cash

July 22, 2001Introduction to.NET12 Metadata A type must be self descriptive: It must describe properties and methods that it exposes. Examples:  The type Integer describes what values it takes and what operations it accepts.  The type Check describes what values (e.g., AccountNo and Amount) it takes and what operations (e.g., Cash, Deposit) it accepts. The Metadata is an integral part of an executable such as CHART.DLL. The DLL describes two things about the Chart type: what it does and how it does it.

July 22, 2001Introduction to.NET13 Assembly To allow others to use a type, the developer must package it in an assembly. A component (delivered in an assembly) is the building block for software construction. Structurally an assembly consists of a manifest and one or more modules. Each module consists of metadata (in IDL) and one or more types (in IL).

July 22, 2001Introduction to.NET14 Manifest The manifest identifies an assembly and declares its contents. It describes:  Identity of an assembly  Its security requirements  The identity of other assemblies it depends on  The types exposed by the assembly