ISYS 573 Special Topic – VB.Net David Chao

The History of VB Early 1960s:BASIC-Beginner’s All-Purpose Symbolic Instruction Code –Teaching –Simple syntax, easy-to-use –Interpreted language – slow Microsoft’s long history of commitment to BASIC –In the 1980s: QuickBasic, QBasic (shipped with DOS) –In the early 1990s, VB 1.0 Visual interface design and creation Even-driven programming Easy database access –2002: VB.Net Challenges: Java, Internet application development

Portability Java: Write Once Run Anywhere Java Source Code Java Byte Code (Intermediate Code) Java Byte Code Java Virtual Machine (JVM) Executable Code

Microsoft’s.Net Language must compliance with Common Language Specification, CLS. Compile the language into Microsoft Intermediate Language (MSIL) code. The MSIL code is then executed in the Common Language Runtime (CLR), which conceptually is same as the JVM, where it is translated into machine code by a compiler.

.Net Architecture Common Language Runtime Base Class Library Data and XML ASP.Net Windows Forms Common Language Specification VB.NetC#C++

Common Language Runtime: –Manages execution of compiled.NET program. –Provides.Net basic services, such as memory management, garbage collection, etc. Base Class library: define all the basic data types such as system.object, numeric, date, etc. Data and XML: Classes work with database (ADO.NET) and XML document. ASP.Net and Forms: Classes that generate user interface. CLS: CLS dictates the minimum group of features that a.Net language must have.

.Net Advantages It is independence from a specific language. Developers can create a.Net application in any.Net compatible language. –.Net moves most of the functionality from the language to the.Net Framework. All.Net language can use these classes. It can exist on multiple platforms, further extending the portability of.Net programs. Facilitate internet application development: –ASP.Net: Web Forms and XML Web services. Universal data access: Data can be accessed by any Internet-connected device.

Programming in the.Net Framework Programming in the.Net Framework means making use of the classes, objects, and members exposed by the Framework, building your own classes on top of these and manipulating the resulting objects using a.Net language. Ex. VB form is derived from System.Windows.Forms.Form class.

Partitioned Application and Component An application designed to run on a distributed system is referred to as a partitioned application. A partition application consists of several parts, and each part perform a specific and well-defined task. Each part of the partitioned application is referred to as a component A component interacts with others via interface: properties, methods, and events supported by the component

Interoperability Between Components To provide object integration and allow functional components that provide specific services to be created and plugged from one application to another.

Benefits of Building Applications from Components Reusability –Many applications can share the services provided by the same component. Manageability –By dividing a program into components, a project can be divided into smaller, more manageable tasks, and each individual programmers can build components for which their skills are best suited. Maintenance –Each component can be maintained as an individual unit. Flexibility –Components are not bound to a physical location, and can be redistributed to other physical location.

XML and.NET.NET Framework uses XML for: –Configuration –Cache dataset –Web services –Web form layouts –Etc. XML data combined with schema are becoming increasingly important.

XML Example John Smith Peter Chen David Chao $45.00 This is a great book Adam Smith $25.00 This is a second great book

Major Topics in ISYS 573 VB.Net language –Event-driven programming –Component programming –Object-oriented programming –Database access.Net Framework classes Internet applications –Web forms –Web services –Web controls –XML