1. .Net A brief introduction to
Seminar on Component Based Software Engineering L.Yang Leiden University

2. What is The .Net ? An Evolution History COM > COM+ > .NET
A Definition
The Microsoft .NET is a system of language (protocol)s, frameworks and services, which aims to align a wide spectrum of Microsoft products and services under a common vision of interconnected devices.

3. Three levels targeted by .Net
Web services;
Deployment platforms (server and clients);
Developer platform.

4. Three levels targeted by .Net (2)
Web Services:
Internet programmable, which need not to be human reader. E.g. .NET Passport, .NET ALERT
Deployment platforms (servers and clients)
Windows becomes more .NET oriented, E.g. efficient Windows XP .NET server, XML
Developer platform
A new developer platform: CLR, frameworks, tools

5. Common Language Infrastructure - CLI
CLI establishes a language-neutral platform;
CLI supports for extensible metadata
The common language runtime (CLR), part of the Microsoft .NET Framework, is the the Microsoft implementation of the CLI specification.
CLR goes beyond CLI compliance and includes support for COM and platform interoperation.

6. Common Language Infrastructure – CLI (2)
CLI has
the specification of execution engine service (e.g. loader, garbage-collecting manager)
Common Type System (CTS)
Common language specification (CLS).

7. Common Language Infrastructure – CLI (3)
Object
Interface
String
array
class
MarshalByRefObject
ValueType
class
ContextBoundObject
Enum
struct
Boolean,Byte,int16,Int32,Int64,Char,Decimal,Guid,Single,Double,DateTime,TimeSpan
class
Enum
Top-level CTS type hierarchy

8. Common Language Infrastructure – CLI (4)
CTS defines a single root type – System.Object for all types
Value type and reference type
Interface is special class
There no primitive types

9. Common Language Infrastructure – CLI (5)
Overloading can take place with the same name and the same signature, but different version
Interface Ishape {
void Draw(); }
Interface Icowboy {
Class CowboyShape:Ishape,Icowboy {
void Ishape.Draw() {…}
void Icowboy.Draw() {…}
I(v1) A C
I(v2) B

10. Visual Studio .Net Visual Studio .NET can support:
Editing, building, and debugging of applications
Modeling, browsing or documentation
Remote and cross debugging in distributed environment

11. Assemblies – the .NET software components
CLI deployment units are called assemblies
An assembly is a set of files in a directory hierarchy
Assemblies are equivalent to old concept resources

12. Assemblies – the .NET software components (2)
The Strong Name of an assembly is equivalent to GUID.
But they are different:
Strong Name
uses hashed public/private key as ID, and
embeds version information and culture information
GUID
A formula generated ID, and
One has no clue about the version of the object the GUID represents

13. Common Language Frameworksc
On top of Common Language Runtime (CLR), the .NET Framework provides a large collection of frameworks.
The .NET Frameworks based on supporting classes which range from fundamental to application specific. This is much equivalent to #include in C/C++
.NET Frameworks contains rich solutions to Web services, Enterprise services, XML and data, etc.

14. Introduction to C# C# has 5 top level definitions Interface
Class (CTS reference class)
Struct (CTS value class)
Enum (CTS enumeration class)
Delegate (CTS reference class)

15. Introduction to C# C# has no primitive type
a + b depends upon the operator overloading

16. Introduction to C# C# allows property operation Get and Set
C# allows abstract array indexer, but you can define only one indexer in one interface