Windows Programming.NET Overview Yingcai Xiao. What is a Computer? From the Webster’s New World Dictionary: 1. A person who computes. 2. A device used

Windows Programming .NET

Overview

Yingcai Xiao

What is a Computer?

From the Webster’s New World Dictionary: 1. A person who computes.2. A device used for computing (an electronic machine which by means of stored instructions and information, perform rapid, often complex calculations or compiles, correlates, and selects data).

What is a program and what is programming?

Programs: stored computer instructions for data processing.

Programming

= Data Structures + Algorithms

Professor Donald E. Knuth

http://www-cs-faculty.stanford.edu/~knuth/

What is Windows Programming?

Windows Programming:

Program for the Windows platform?

Program for the Internet on the Windows platform!

What is .NET?

.Net is a framework for developing OS-platform-independent, programming- language-independent, web-enabled, distributed applications.

Traditional Compilation (Linking)

Source Code for Language 1

Language 1 Compiler on OS1

Binary Code for OS1

OS1



Binary Code for OS2

OS2

Common Binary Code?

OS-Independent Code: Intermediate Languages

The trend to support OS-independent binary code is to compile the source code into the binary format of an intermediate language.

And to provide an interpreter for the intermediate language on each OS to translate the binary code of the intermediate language into the native binary code of the OS.

OS-Independent Compilation: Intermediate Language



Intermediate Binary Code

OS1

Intermediate Code Interpreter OS1

OS2


Binary Code for OS2Binary Code for OS1

Intermediate Code Interpreter OS2

Java Intermediate Language: Java Bytecode

Java Source Code (.java)

Java Compiler (javac) on OS1

Java Bytecode (.class)

OS1

Java Interpreter on OS1 (java)

OS2



Java Interpreter on OS2 (java)

Program statements are interpreted one at a time during the run-time.

JIT Compiler

An interpreter interprets intermediate code one line at a time. Slow execution.

A JIT (Just-In-Time) Compiler compiles the complete code all at once just into native binary code before execution. Faster execution.

JIT Complier: Java Bytecode Compiler

Java Source Code (.java)


Java Bytecode (.class)

OS1

Java JIT Compiler on OS1

OS2



Java JIT Compiler on OS2

All programming statements are compiled at compile time.

.NET OS-Platform-Independence

MSIL: Microsoft Intermediate Language



MSIL Code

OS1

MSIL JIT Compiler on OS1

OS2



MSIL JIT Compiler on OS2

JIT Compilation in .NET

All MSIL code are JIT-compiled to native binary code before execution. No run-time interpretation, faster execution.

A Common Language?

.NET Common Language Runtime

To make .NET language independent, CLR (Common Language Runtime) is defined as the runtime environment.

CLR defines CTS (Common Type System) which should be followed by all languages to be used in the .NET framework.

Syntax: int, for, ..

Semantics: multiple inheritance is not allowed in CTS

The code that follows CTS standard is called managed code.

regular C++ supports multiple inheritance

managed C++ does not support multiple inheritance

.NET Language-Independence

CLR: Common Language Runtime



MSIL Code Confirming CTS (Managed Code)

OS1

CLR on OS1

OS2



CLR on OS2


.NET Architecture for Language and Platform Independence(fan-in and fan-out on MSIL)



OS1

CLR on OS1

OS2



CLR on OS2


MSIL Code Confirming CTS (Managed Code)

CLI (Common Language Infrastructure)

CLR/CTS for Everyone?

CLI : Common Language Infrastructure

A specification defines an environment for multiple high-level languages to be used on different computer platforms.

Created by Microsoft based on .NET, standardized by MS, Intel, HP and others, ratified by ECMA and ISO.

.NET is an implementation of CLI for desktop systems.

.NET Compact Framework is an implementation of CLI for portable devices.

Open Source implementations: Mono development platform (Novell), Portable .NET (dotGNU)

CLI (Common Language Infrastructure) SpecificationOpen Architecture for Language and Platform Independent Programming



OS1

CLR for OS1

OS2



CLR for OS2


CIL (Common Intermediate Language) Code

Confirming CTS (Common Type System)

Even though, CLI/CTS/CLR can make a program written in any language to run on any platform, the entire program (including all libraries used) has to be on the platform before running.

Can we have part of a program on one computer and another part of the same program on another computer?

Distributed Computing. A program is divided into multiple parts and different parts are distribute on different computers.

e.g. virtual surgery.

Web Enabled & Distributed

.Net is Web-enabled and Distributed

To run distributed code on the web, we need a standard way to register the code and a standard way to access the code.

Registration:

UDDI Registry: Universal Description, Discovery, and Integration.

Access:

SOAP: Simple Object Access Protocol

WSDL: Web Service Description Language

.NET Architecture for Web-based Distributed Computing

Client 1

Client 2

Web Service 1

UDDI Registry 1

WSDL Interface 1

UDDI Registry 2

Web Service 2 WSDL Interface 2

SOAP

SOAP

WEB

Web Service Example

.NET Passport (one login for the whole Internet)

www.passport.com (run by Microsoft)

www.ubid.com (An online auction shop using Passport web service)

Windows Live (one location to get all you need from the Internet)

http://get.live.com/ (run by Microsoft)

Windows Live ID is replacing Passport ID.

.NET Framework Compositions

Common Language Runtime (CLR ): provides the runtime environment for MSIL code.

.Net Framework Class Library (FCL) : provides standard code for building common .Net applications.

Classes in FCL are grouped into namespaces.

.Net Framework Class Library

System

Windows

Forms

(GUI)

Web Data

(Database)

Enterprise Services

XML

(Data Description)

String,

…

UI ServicesConnection

DataSet XmlDocument


The most important groups are “the gang of four”:

• Windows Forms: for building GUIs for .Net applications, language independent.

• ASP.NET: Active Server Pages for .Net, for building web-accessible applications.

• ADO.NET: ActiveX Data Objects for .Net, for accessing data in a database.

• Enterprise Services: for accessing COM+ services (transactions, object pooling).

OS

Web Services

Distributed

Applications

Common Language Runtime


Browser

Accessible

Remote Applications

Other Applications

Local

Applications

.NET Application Types

.Net & COM

MFC: Microsoft Foundation Class, code reuse within an application (process)

COM: Component Object Model, code reuse across applications (processes)

DCOM: Distributed COM, code reuse across systems

COM+: Internet-based Enterprise COM, code reuse across the Internet

.NET: COM+ 2.0, all COM+ services are available in .NET, even those not in managed code, interoperable with COM-based applications

.NET My Services

Applications providing access to personal information over the Internet.

• Passport (authentication)

• .NET Inbox (e-mail)

• .NET Documents (Internet-accessible storage)

• .NET Alerts (sending alert messages)

• .NET Calendar

• .NET Contacts

• .NET Wallet (payment inform)

• .NET List (to-do list)

.NET Enterprise Servers

Internet Information Services (IIS): web server

Commerce Server: e-commerce server

SQL Server: database server

Exchange Server: MS exchange services

Mobile Information Server: wireless server

Internet Security and Acceleration (ISA) Server:

firewall, proxy, …

BizTalk: B2B (Business-to-Business) server

A Common Language for the Internet (free of compilation and translation)?

A Common Language for the Internet• Tim Berners-Lee• ASCII text (ISO/IEC 8859-1) is platform-independent. • HTTP (Hyper Text Transport Protocol)

e.g. GET wp.html

Assembly Language for the Internet• HTML (Hyper Text Markup Language)

High-level language for the Internet)hyper text: text that describes other texttags: type definition of text in text

<title>WP</title>all tags are predefined in HTMLonly system defined types, no user defined types

Recognizable by all types of computers. (World Wide Web)

A Common Language for the Internet

XML (eXtensible Markup Language)Allow user defined tags (types)

SOAP (Simple Object Access Protocol)Standards for defining objects for the InternetBased on XML

WSDL (Web Service Description Language)Standards for describing web services for the InternetBased on XML