Windows Programming .NETOverviewYingcai Xiao

What is a Computer?From the Websters 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 + AlgorithmsProfessor 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)

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 LanguageSource Code for Language 1Language 1 Compiler on OS1Intermediate Binary CodeOS1Intermediate Code Interpreter OS1OS2Language 1 Compiler on OS2Binary Code for OS2Binary Code for OS1Intermediate Code Interpreter OS2

Java Intermediate Language: Java BytecodeJava Source Code (.java)Java Compiler (javac) on OS1Java Bytecode (.class)OS1Java Interpreter on OS1 (java)OS2Java Compiler (javac) on OS2Binary Code for OS2Binary Code for OS1Java 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 CompilerJava Source Code (.java)Java Compiler (javac) on OS1Java Bytecode (.class)OS1Java JIT Compiler on OS1OS2Java Compiler (javac) on OS2Binary Code for OS2Binary Code for OS1Java JIT Compiler on OS2 All programming statements are compiled at compile time.

.NET OS-Platform-Independence MSIL: Microsoft Intermediate LanguageSource Code for Language 1Language 1 Compiler on OS1MSIL CodeOS1MSIL JIT Compiler on OS1OS2Language 1 Compiler on OS2Binary Code for OS2Binary Code for OS1MSIL 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 inheritancemanaged C++ does not support multiple inheritance

.NET Language-Independence CLR: Common Language RuntimeSource Code for Language 1Language 1 Compiler on OS1MSIL Code Confirming CTS (Managed Code)OS1CLR on OS1OS2Language 2 Compiler on OS2Binary Code for OS2Binary Code for OS1CLR 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 1Language 1 Compiler on OS1OS1CLR on OS1OS2Language 2 Compiler on OS2Binary Code for OS2Binary Code for OS1CLR on OS2 Source Code for Language 2MSIL 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 ProgrammingSource Code for Language 1Language 1 Compiler on OS1OS1CLR for OS1OS2Language 2 Compiler on OS2Binary Code for OS2Binary Code for OS1CLR for OS2 Source Code for Language 2CIL (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 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 LibrarySystemWindowsForms(GUI)WebData(Database)Enterprise ServicesXML(Data Description)String,UIServicesConnectionDataSetXmlDocument

.Net Framework Class LibraryThe 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).

OSWeb ServicesDistributedApplicationsBrowserAccessibleRemote ApplicationsOther Applications LocalApplications.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 ServicesApplications providing access to personal information over the Internet. .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 InternetTim Berners-LeeASCII text (ISO/IEC 8859-1) is platform-independent. HTTP (Hyper Text Transport Protocol) e.g. GET wp.htmlAssembly Language for the InternetHTML (Hyper Text Markup Language)High-level language for the Internet)hyper text: text that describes other texttags: type definition of text in textWPall tags are predefined in HTMLonly system defined types, no user defined typesRecognizable by all types of computers. (World Wide Web)

A Common Language for the InternetXML (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