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)

.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

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

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

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

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

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)

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

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

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?)

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?)

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

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’

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

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