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

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 Source Code for Language 1 Language 1 Compiler on OS2 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 Source Code for Language 1 Language 1 Compiler on OS1 Intermediate Binary Code OS1 Intermediate Code Interpreter OS1 OS2 Language 1 Compiler on 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 Compiler (javac) on OS2 Binary Code for OS2Binary Code for OS1 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 Compiler (javac) on OS1 Java Bytecode (.class) OS1 Java JIT Compiler on OS1 OS2 Java Compiler (javac) on OS2 Binary Code for OS2Binary Code for OS1 Java JIT Compiler on OS2 All programming statements are compiled at compile time.

.NET OS-Platform-Independence MSIL: Microsoft Intermediate Language Source Code for Language 1 Language 1 Compiler on OS1 MSIL Code OS1 MSIL JIT Compiler on OS1 OS2 Language 1 Compiler on OS2 Binary Code for OS2Binary Code for OS1 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 Source Code for Language 1 Language 1 Compiler on OS1 MSIL Code Confirming CTS (Managed Code) OS1 CLR on OS1 OS2 Language 2 Compiler on OS2 Binary Code for OS2Binary Code for OS1 CLR on OS2 Source Code for Language 2

.NET Architecture for Language and Platform Independence (fan-in and fan-out on MSIL) Source Code for Language 1 Language 1 Compiler on OS1 OS1 CLR on OS1 OS2 Language 2 Compiler on OS2 Binary Code for OS2Binary Code for OS1 CLR on OS2 Source Code for Language 2 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) Specification Open Architecture for Language and Platform Independent Programming Source Code for Language 1 Language 1 Compiler on OS1 OS1 CLR for OS1 OS2 Language 2 Compiler on OS2 Binary Code for OS2Binary Code for OS1 CLR for OS2 Source Code for Language 2 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 DescriptionLanguage

.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 2WSDL Interface 2 SOAP WEB

Web Service Example.NET Passport (one login for the whole Internet) (run by Microsoft) (An online auction shop using Passport web service) Windows Live (one location to get all you need from the Internet) (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) WebData (Database) Enterprise Services XML (Data Description) String, … UI Services Connection DataSet XmlDocument

.Net Framework Class Library 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.Net Framework Class Library 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 ( ).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 ) 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 text tags: type definition of text in text WP all tags are predefined in HTML only 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 Internet Based on XML  WSDL (Web Service Description Language) Standards for describing web services for the Internet Based on XML