Windows Programming .NETOverview Yingcai Xiao
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 Computer?
Programs: stored computer instructions for data processing. Programming = Data Structures + Algorithms Professor Donald E. Knuth http://www-cs-faculty.stanford.edu/~knuth/ What is a program and what is programming?
Windows Programming: Program for the Windows platform? Program for the Internet on the Windows platform! What is Windows Programming?
.Net is a framework for developing OS-platform-independent, programming- language-independent, web-enabled, distributed applications. What is .NET?
Source Code for Language 1 Source Code for Language 1 Language 1 Compiler on OS1 Language 1 Compiler on OS2 Binary Code for OS1 Binary Code for OS2 OS1 OS2 • Traditional Compilation (Linking)
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 Code: Intermediate Languages
OS-Independent Compilation: Intermediate Language Source Code for Language 1 Language 1 Compiler on OS1 Language 1 Compiler on OS2 Intermediate Binary Code Intermediate Code Interpreter OS1 Intermediate Code Interpreter OS2 Binary Code for OS1 Binary Code for OS2 OS1 OS2
Java Intermediate Language: Java Bytecode Java Source Code (.java) Java Compiler (javac) on OS1 Java Compiler (javac) on OS2 Java Bytecode (.class) Program statements are interpreted one at a time during the run-time. Java Interpreter on OS1 (java) Java Interpreter on OS2 (java) Binary Code for OS1 Binary Code for OS2 OS1 OS2
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 Compiler
JIT Complier: Java Bytecode Compiler Java Source Code (.java) Java Compiler (javac) on OS1 Java Compiler (javac) on OS2 Java Bytecode (.class) All programming statements are compiled at compile time. Java JIT Compiler on OS1 Java JIT Compiler on OS2 Binary Code for OS1 Binary Code for OS2 OS1 OS2
MSIL: Microsoft Intermediate Language Source Code for Language 1 Language 1 Compiler on OS1 Language 1 Compiler on OS2 MSIL Code .NET OS-Platform-Independence MSIL JIT Compiler on OS1 MSIL JIT Compiler on OS2 Binary Code for OS1 Binary Code for OS2 OS1 OS2
All MSIL code are JIT-compiled to native binary code before execution. No run-time interpretation, faster execution. JIT Compilation in .NET
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 Common Language Runtime
CLR: Common Language Runtime Source Code for Language 1 Source Code for Language 2 Language 1 Compiler on OS1 Language 2 Compiler on OS2 MSIL Code Confirming CTS (Managed Code) .NET Language-Independence CLR on OS1 CLR on OS2 Binary Code for OS1 Binary Code for OS2 OS1 OS2
Source Code for Language 1 Source Code for Language 2 Language 1 Compiler on OS1 Language 2 Compiler on OS2 MSIL Code Confirming CTS (Managed Code) .NET Architecture for Language and Platform Independence (fan-in and fan-out on MSIL) CLR on OS1 CLR on OS2 Binary Code for OS1 Binary Code for OS2 OS1 OS2
CLI (Common Language Infrastructure) CLR/CTS for Everyone?
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
Source Code for Language 1 Source Code for Language 2 Language 1 Compiler on OS1 Language 2 Compiler on OS2 CIL (Common Intermediate Language) Code Confirming CTS (Common Type System) CLI (Common Language Infrastructure) Specification Open Architecture for Language and Platform Independent Programming CLR for OS1 CLR for OS2 Binary Code for OS1 Binary Code for OS2 OS1 OS2
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.
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 is Web-enabled and Distributed
.NET Architecture for Web-based Distributed Computing Client 1 UDDI Registry 2 SOAP Client 2 UDDI Registry 1 SOAP Web Service 1 WSDL Interface 1 Web Service 2 WSDL Interface 2 WEB
.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. Web Service Example
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 Compositions
.Net Framework Class Library System Windows Web Data (Database) Enterprise Services XML (Data Description) String, … Forms (GUI) UI Services Connection 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). .Net Framework Class Library
.Net Framework Class Library Common Language Runtime Browser Accessible Remote Applications Local Applications Other Applications Web Services Distributed Applications .NET Application Types OS
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 & COM
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 My Services
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 .NET Enterprise Servers
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 text • tags: type definition of text in text • <title>WP</title> • 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 A Common Language for the Internet • WSDL (Web Service Description Language) Standards for describing web services for the Internet Based on XML