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prepared by James T. Perry University of San Diego

prepared by James T. Perry University of San Diego. Ch. 1: Introduction to VB. Writing windows applications with VB Prog. languages: procedural, object oriented, & event driven Writing VB projects The VB environment Writing your first VB project Finding & fixing errors Visual Basic help.

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prepared by James T. Perry University of San Diego

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  1. prepared by James T. Perry University of San Diego

  2. Ch. 1: Introduction to VB • Writing windows applications with VB • Prog. languages: procedural, object oriented, & event driven • Writing VB projects • The VB environment • Writing your first VB project • Finding & fixing errors • Visual Basic help

  3. Labels Text boxes Frame Check boxes Option buttons Command buttons Image Picture box Writing Windows Apps. with VB • The Windows GUI

  4. Graphic User Interface • Graphic User Interface (GUI) comprises • Forms • Controls • Event-driven programming

  5. Prog. Languages: procedural, object oriented, & event driven • The Object Model • Objects (nouns) controls • Properties (adjectives) form1.Caption • Methods (verbs) debug.print • Versions of Visual Basic • Working Model • Learning Edition • Professional Edition • Enterprise Edition

  6. Planning Visual Basic Projects • The three-step process for planning projects • Design the user interface Sketch the screens with forms and controls needed • Establish the objects' properties Write down the properties for each object • Plan the Basic code Write out pseudocode for actions your program will perform

  7. Writing Visual Basic Projects • The three-step process for writing projects • Design the user interface Create the forms and controls you previously sketched • Set the objects' properties Give each object a name and set their properties • Write the Basic code Write out Visual Basic code to carry out your application's actions

  8. Visual Basic Projects • Visual Basic projects create several files • Project file: .VBP Holds the names of other files in the project • Form files: .FRM Each form is saved as a separate file Form file contains a description of a form's objects and the Basic code attached to a form • Standard code module: .BAS (optional) • Custom controls: .OCX (optional) • Form information: .VBW

  9. The Visual Basic Environment • Form, Project Explorer, Properties, and Form Layout Windows • Toolbox • Main Visual Basic window • Toolbar, Form location & size information • Help • Design- , Run- , and Break Time

  10. The Toolbox • Tool box contents vary based on which version of Visual Basic you are running. • Toolbox contains a common set of tools across all VB versions

  11. The Visual Basic Toolbar • The buttons on the toolbar are shortcuts • Toolbar buttons are a quick way to activate frequently used commands • Each button stands for a command that you can also select a the Visual Basic menu

  12. Writing Your First VB Project • Set up your Visual Basic workspace • Define user interface • Set properties • Write code • Visual Basic code statements • Run, save, open, modify, & print the Hello World project • Documentation

  13. Set Up Your VB Workspace • Set up Options to reflect these settings:

  14. Define the User Interface • Resize the form • Drag the lower-right handle to enlarge the form • Drag any handle in the middle of a side to enlarge the form in that direction only • Place controls on the form • Click the label tool • Click and drag the mouse (a crosshair) to place the control on the form

  15. Set Properties • Set the Name and Caption properties • Always set the Name property before writing code • Next, set the Caption property • The Name property identifies the object internally--so you can refer to it in code • The Caption property externally idenfities an object

  16. Write Code • You write code enclosed in event procedures, which respond to typical VB events. Private Sub cmdPush_Click() . . . (your code goes here) End Sub • VB automatically supplies the event procedure Sub/End Sub statements

  17. Visual Basic Code Statements • Remark statement is any code line beginning with an apostrophe • Assignment statement • End statement

  18. Code the Event Procedures for Hello World • Write the Push event code for the Push Me button (cmdPush) • Write the Push event code for the Exit button (cmdExit)

  19. Run/Save/Open/Modify the Project • Test the project: • Click Run, Start (or click the Start button on the toolbar) • Click the Push Me button • Click the Exit button • Save the project and the form • Make modifications to the form • Print the project documentation: • Form Image, Code, and Form as Text

  20. Finding & fixing errors • Compile (syntax) errors • Run-Time (semantic) errors • Logic errors • Project Debugging

  21. Naming Conventions • Objects have special prefixes that help identify the object's general type • Programmers follow the conventions because it simplifies coding and debugging • Never use default names for objects

  22. Visual Basic Help • Help includes all of the Microsoft Developer Network (MSDN) library. • The Working Model does not contain the extensive MSDN facilities • Access MSDN online at http://msdn.Microsoft.com

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