1. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott COMP6325 Advanced Web Technologies Dr. Paul Walcott The University of the West Indies Session 4 – The Microsoft.NET Framework – Part I Summer 2008

2. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Objectives  In this session the student will: Describe the.NET architecture  Managed code  The Common Language Runtime (CLR) Create a C# application

3. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott What is.NET  A runtime environment  ASP.NET Active server pages – a programming model for creating web pages  Web Services exposing functions to Clients on the Internet  Windows Forms User interface

4. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott What is.NET cont’d  ADO.NET for database access  And much, much more.

5. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Managed Code (Devhood, nd), (Platt, 2003)  Code that is run under the.NET framework is called managed code Legacy code is considered unmanaged  The goals of managed code include security, OOD and robustness  Managed code is characterised by: A common intermediate language Metadata Just-in-time (JIT) compilation

6. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Common Language Runtime (CLR) (Devhood, nd)  As managed code is run it is supervised by the common language runtime (CLR)  The CLR includes features such: as automatic memory management Type safety Thread management Security

7. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Common Language Runtime (CLR) (Devhood, nd)  The CLR is similar to the Java Virtual machine (JVM), but has some important differences For example, unlike the JVM, the CLR does not interpret, it compiles

8. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott CLR cont’d

9. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott CLR cont’d  A language, such as C++ or C# is translated into an abstracted assembly language called the Microsoft Intermediate Language (IL) An assembly language for a machine that does not exist  At runtime the IL is translated into the machine language of the native machine and executed This is referred to as JIT compilation

10. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott CLR cont’d  The metadata that is stored with the IL describes class definitions, methods calls and return values

11. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Framework Class Library (FCL)  This is a class library designed for extendibility and composeability  It allows the reading of files, the displaying of windows, the creation of forms, and so on  As discussed in the previous session, the class library is arranged in a hierarchy of namespaces  For further information see (Devhood, nd) and the SDK Documentation (access through the Start menu)

12. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Finally, the big picture

13. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott C# Programming  In this session we will continue our look at the C# programming language: Methods Namespaces Classes

14. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Activity  Create a Person class with: Attributes  age, weight, description of the person Methods  Assessors, Mutators  Diet – based on the characteristics of the person Namespace  LifeForm.HumanBeing  Then create an application that creates Person objects for all of the members of the class; and allows a user to manipulate these objects using a command interface

15. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Conclusion  In this session The architecture of the.NET framework was described A simple C# application was created

16. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott References DevHood, “Introduction to the.NET Framework.” Available online at http://www.devhood.com/training_modules/dist-a/Intro.NET/intro.net.htm http://www.devhood.com/training_modules/dist-a/Intro.NET/intro.net.htm Platt, D., “Introducing Microsoft.NET”, Third Edition, Microsoft Press, 2003