Introduction to Visual Basic and the VB IDE

Motivation We'd like to be able to write programs that will run on Windows We'd like to use Rapid Application Development methods We’re interested in developing object-oriented, event-driven applications • MyAge, YourGrade, and ThisTest were declared on the previous slides - must be declared first to use them

Basic 10 sum = 0 20 FOR i = 1 to 100 30 sum = sum + i 40 NEXT i 50 avg = sum / 100 60 PRINT "The average is " avg 70 END

RAD Rapid Application Development Easily develop interface prototypes Accelerates delivery of system Better user feedback and testing WYSISYG development

Object-oriented Programming Think in real-world concepts Objects have Properties/attributes (nouns) Actions/events (verbs) Akin to a "record" on steroids!  Groups data and procedural abstraction together Provides for encapsulation & information hiding

Event-Driven Programming Basic and Pseudocode run from top to bottom Main program/algorithm in control Event-driven programs respond to events Usually graphical (forms, buttons, controls) Instructions are executed in response to events Button press, control change, form close, etc.

Anatomy of a VB Program User clicks on the cmdBorder button Form Controls User clicks on the cmdBorder button A Click() event is generated The cmdBorder_Click() method is executed

Event-driven vs. Procedural algorithm CalcAges // create the 4 age variables Age1, Age2, Age3, Age4 isoftype Num // prompt the user and then read in the // numbers print("Please enter 4 ages") read(Age1, Age2, Age3, Age4) // I need a place to store the average avg isoftype Num // calc the average avg <- (Age1 + Age2 + Age3 + Age4) / 4 // display it back to the user print("The average age is ", avg) endalgorithm

VB Program Development Design Create the User Interface (UI) Set form and control properties Code event handlers Save and test/debug your program often! Create executable file Create setup program (for deployment on other computers)

The VB IDE

Design vs. Run Time Design time When you’re building your program Some properties may not be set Run time When you run your program Events are generated from user (buttons, etc.) Opens up more properties of controls

Versions Visual Basic has evolved and will continue to evolve We will be using VB.Net

File Types VBP Visual Basic Project (meta file) VBW Visual Basic Workspace (settings of project) FRM Form (form, control, methods, & attributes) EXE Self-contained executable program SCC Visual SourceSafe file (for versioning/collaboration) others to be announced as needed

MSDN Microsoft Developers Network Your lifeline Your best friend when programming On-line or on CD-Rom http://www.msdn.microsoft.com Mouse over “Libraries” and click “MSDN Libraries” Live it; Love it; Use it!

Summary VB is based on Basic VB is a RAD language VB is an event-driven language VB is an object-oriented language VB comes in different versions and editions Important terms to know/understand: Form, control, method, event, attribute/property IDE, RAD, OOP