1. PROBLEM SOLVING The first step in writing instructions to carry out a task is to determine what the output should be (What should the task produce?) The second step is to identify the data, or input, necessary to obtain the output The final step is to determine how to process the input to obtain the desired output INPUTOUTPUTPROCESSING

2. PROGRAM DESIGN TOOLS Flowcharts: graphically depict the logical steps to carry out a task and show how the steps relate to each other Pseudocode: uses English-Like phrases with some (Visual Basic) terms to outline the task Hierarchy Charts: show how the different parts of the program relate to each other (referred to as Structure Charts, HIPO (Hierarchy plus Input-Process-Output) Charts, Top-Down Charts or VTOC (Visual Table of Contents) Charts.)

3. RENTING A VIDEO START GET CUSTOMER NUMBER REFUSE RENTAL PROCESS RENTAL PROCESS GET VIDEO NUMBER VALIDATE NUMBER PROCESS CUSTOMER NUMBER END VALIDATE NUMBER Valid Invalid Valid

4. Achieve program clarity through Structured Programming Event-Driven Programming Object-Oriented Programming Newer Methodologies Event-Driven Programming - work with Events Object-Oriented Programming - work with Objects The internal structure of Objects and Events is best built using Structured Programming Techniques Also, the logic of manipulating objects is occasionally best expressed with Structured Programming

5. What is Visual Basic? Visual Basic (VB) is a Microsoft Windows programming language (SOFTWARE development language) Visual Basic is derived from the BASIC (Beginners All- purpose Symbolic Instruction Code) programming language BASIC was developed in the mid-1960s The widespread use of BASIC led to many enhancements to the language In the late 1980s and early 1990s, with the development of the Microsoft Windows (Graphic User Interface) GUI, the natural evolution of BASIC was Visual Basic (created by Microsoft in 1991)

6. VB greatly simplifies the development of Microsoft Windows-based Applications Since 1991, 6 versions of VB have been released, with the latest Visual Basic 6 appearing in September 1998. Microsoft provides several versions of VB, namely the Learning Edition, the Professional Edition and the Enterprise Edition VB programs are created in an Integrated Development Environment (IDE). The IDE allows a programmer to create, run and debug VB programs conveniently. The process of rapidly creating an application is typically referred to as Rapid Application Development (RAD). VB is the most widely used RAD language.

7. The Visual Basic Environment In using VB you will learn to write computer programs that run in the Microsoft Windows environment Projects will look and act like standard Windows programs VB provides the tools you need to create windows with familiar elements like: Menus, Text Boxes, Command Buttons, Option Buttons, Check Boxes, List Boxes, and Scroll Bars

8. Microsoft Windows uses a Graphic User Interface (GUI) The Windows GUI defines how the various elements look and function Within VB there is a Toolbox of these elements In VB you will create new Windows called Forms Using the toolbox to add the various elements, called Controls, to the form VB programming is known as Event-Driven Programming

9. In VB you work with Objects, which have Properties and Methods Objects: Think of an Object as a thing, or a noun Examples of Objects are Forms and Controls Forms are the Windows and Dialog Boxes that you place on the screen Controls are the elements you place inside a form, such as Text Boxes, Command Buttons, and List Boxes

10. Properties: Think of Properties as adjectives that describe objects Properties tell something about an Object, such as the name, colour, size, location, and how it will behave When you refer to a Property [1] Name the Object [2] Name the Property (Example: Form1.Caption) The Caption Property of the Object (Form) called Form1

11. Methods: Methods are the verbs of Object-Oriented Programming Methods are Actions associated with Objects Example of Methods include Move, Print, Resize, and Clear Refer to Methods as: Object.Method (Example: Form1.Print) Sends output (Prints) to the Object (Form) called Form1 (Question: What does this Method refer to?) Printer.Print

12. There is a ‘Three-Step’ process in Planning and Programming a VB project Planning [1] Design the User-Interface [2] Plan the Properties [3] Plan the VB ‘Basic’ Code (in the planning stage this is referred to Pseudocode) Programming [1] Define the User-Interface [2] Set the Properties [3] Write the VB ‘Basic’ Code

13. Visual Basic Project Files:.VBP file: Project File: a small text file that contains the names of other files in the project, as well as some information about the VB environment (release 2.0 and 3.0 of VB,.MAK extensions for project files).FRM file: Form File: each form in the project is saved in a.FRM extension. Each form file holds a description of all Objects and their Properties for the form, as well as the Basic Code written (In VB each of these Form Files is referred to as a Form Module)

14. .BAS file: Standard Code Modules: hold VB ‘Basic’ statements that can be accessed from any Form.BAS files are used in multiform projects.OCX file: Custom Controls: additional controls/custom controls are stored in.OCX files. If projects include controls that are not part of the Standard Control Set, then.OCX file names will be included in the project (All controls have.OCX extensions, however, this is implicit in controls internal to the VB Environment, and these extensions are not visible to the user).VBW file: after the project is saved, VB automatically adds one more file to the project, which holds information about each of the project Forms

15. Project Tip Create a New Folder for a project, before creating any files for the project Save the.VBP file Save the.FRM files, and Save the.BAS files into the folder Then if the project needs to be copied or transferred from the ‘C: Drive’ to the ‘A: Drive’, all of the project files can be transferred together within the folder, and no component parts (.VBP,.FRM,.OCX[if existing])of the project will be lost Component parts of a project can be lost and always save each component part separately

16. The VB Environment VB Environment, where projects are created The various windows, in the VB Environment, can be moved, resized, opened, and closed The windows within a project can be customised

17. FORM TOOLBOX FORM WINDOW TOOLBAR MENU BAR PROJECT EXPLORER WINDOW FORM LOCATION & SIZE INFORMATION PROPERTIES WINDOW PROPERTIES HELP PANE FORM LAYOUT WINDOW FORM1: NAME OF THE OBJECT FORM: CLASS OF THE OBJECT

18. POINTER (NOT A CONTROL) LABEL FRAME DRIVELISTBOX FILELISTBOX LINE DATACONTROL CHECKBOX COMBOBOX HSCROLLBAR TIMER DIRLISTBOX SHAPE IMAGE OLE PICTUREBOX TEXTBOX COMMAND BUTTON OPTIONBUTTON LISTBOX VSCROLLBAR

19. The Form Window is where the forms are designed that make up the User-Interface Always create a ‘User-Friendly’ User-Interface Standard windows techniques can be used to change the size and location of the form ‘Mouse-Driven Environment’ By default, a new form created in a new project, is called Form1, when the file is saved, the programmer assigns a more meaningful name to the file (?: What is the extension?)

20. The Project Explorer Window holds the filenames of the files included in the project The windows Title Bar holds the name of the project, which is Project1 by default, until saved and given a more meaningful name (?: What is the extension?)

21. The Properties Window, its use relates to setting the properties for the objects in the project Check Box 1/0, True/False Option Box 1/0, True/False Command Button ‘Name’ how the computer recognises/identifies the control/object ‘Caption’ relates to the user identification of the control/object Text Box ‘Text’ property: ‘Blank’ ‘Name’ property: like command button Form Window State ‘Maximise’, relates to maximising the form when the project is executed

22. The Form Layout Window, this indicates the position of the form on the desktop, when the execution of the project begins The Toolbox holds the tools that are used to place controls on the form The tools displayed on the toolbox, may be different, depending on the edition and release of VB being used ‘Professional Edition’

23. The Main Visual Basic Window holds the VB menu bar, the toolbar, and the form location and size information The Toolbar, the buttons on the toolbar can be used as shortcuts for frequently used operations Each button represents a command that can be executed by clicking on the button or by choosing a command from the menu bar The Form Location and Size Information identifies the size and position of the form on the screen

24. Help VB has an extensive ‘Help’ facility VB contains what is called ‘Context-Sensitive’ help

25. Design Time, Run Time, Break Time VB has 3 distinct modes: Design Time: relates to designing the ‘User- Interface’ and writing code Run Time: relates to testing and running the project Break Time: if there is a ‘run-time error’ or project execution is paused

26. VB Project Example The first ‘Event-Driven’ project will create a form with 3 controls It will display the message ‘Hello world’ when the user clicks the ‘Push Me’ command button, and will terminate when the user clicks the ‘Exit’ command button (Tip: If the Project Explorer Window/Properties Window/Toolbox are not displayed, open the View menu and select Project Explorer Window/Properties Window/ Toolbox

27. Project Tips Do not confuse the ‘Name’ and ‘Caption’ properties ‘Name’ refers to the control in the VB code ‘Caption’ refers to the users view on the form VB sets both of these properties to the same value by default, and therefore it is easy to confuse them NB: Always set the ‘Name’ property of controls before writing code If the ‘Name’ of an object is changed after the code has been written, then the code becomes separated from the object and the program does not run properly

28. When a VB project is running, the user can do many things Each action by the user causes an ‘Event’ to occur in the VB project If you write VB code for a particular event, the VB will respond to the event and automatically execute your procedure (eg: clicking on a command button) VB ignores events for which no procedures are written (eg: moving the mouse resizing a window opening another application)

29. VB code written in procedures We deal with writing code in ‘Sub Procedures’ or ‘Sub Programs’ Begins with: Private Sub Ends with: End Sub

30. VB automatically names the event proceudres The ‘Name’ consists of the object name, an underscore ( _ ), and the name of the event (name of the command button is cmdPush and there is a Click event for the command button Therefore, the name of the Sub Procedure: cmdPush_Click

31. VB Code Statements 3 types of VB statement The Remark statement, known as comments, are used for project documentation only Begin with an apostrophe Not executable Comments make the project more readable and understandable The inclusion of comments is seen as good programming practice It is a good idea to comment within the logic of the project, especially if the purpose of any statement is unclear

32. The Assignment statement assigns a value to a property or variable Assignment statements operate form Right to Left, that is the value appearing on the right hand side of the equal sign (=) is assigned to the property named on the left of the equal sign (Example: lblTitle.FontSize = 12 Let lblTitle.FontSize = 12) The use of ‘Let’ is optional, and its use may improve the readability of the project code

33. When the value to assign is ‘actual text’, known as a Literal, it is enclosed in quotation marks This allows any combination of alpha and numeric characters to be typed However, if the value is numeric, (eg: 12), do not enclose it in quotation marks Do not place quotation marks around the term True or False, as VB recognises these as Special Key Terms (Blue in colour, within VB code) The End statement stops the execution of the project

34. Private Sub cmdPush_Click ‘Display the ‘Hello World’ Message lblMessage.Caption = “Hello World” End Sub *********************************************** Private Sub cmdExit_Click ‘Exit the project End End Sub Comment Assignment