What is VB? Visual Basic ( VB ) is an event driven programming language and associated development environment created by Microsoft. In business programming, it has one of the largest user bases. It is derived heavily from BASIC and enables rapid application development (RAD) of graphical user interface (GUI) applications, access to databases using DAO, RDO, or ADO, and creation of ActiveX controls and objects. A programmer can put together an application using the components provided with Visual Basic itself. As of 2003, 52 percent of software developers used Visual Basic, making it the most popular programming language at that time. 43 percent of those Visual Basic developers, however, planned to move to other languages. The popularity of Visual Basic perhaps results from its easy to understand syntax. Like all other Turing complete programming languages, it can also be used to create arbitrarily complex applications. Programs written in Visual Basic can use the Windows API, but doing so requires external function declarations.
Visual Basic is not an acronym anymore. It used to be. When the language was invented in the early 70's, BASIC stood for B eginners' A ll-purpose S ymbolic I nstruction C ode, When you work with RAD (Rapid Application Development) tools like VB in a graphical interface environment
What Can Visual Basic Be Used For? to write games, phone books, modem communications software, encryption utilities, GUIs and much more Database handling Internet !
Interpreter A program that will read the code of a specific language, compile it, and load it into the systems memory. Every time this program is run, it must be re-interpreted, and therefore interpreted languages can never be as fast as fully compiled languages. Languages that use interpreters include Basic (and specialized forms such as QBasic ) , Perl , PHP , MUMPS , and many others. Computer Science ) Compiler A compiler is any of a family of programs used to turn source code into an executable program . This action is called compiling . The opposite of compiling is decompiling , which can be done by a decompiler .
What Is The Syntax Like? The commands are almost all plain English words. The syntax is very much like the way you would think while writing it. An Example Visual Basic Program This is an example of some Visual Basic code. 'Declare a String variable Dim Message As String 'Store Hello World in a message. Let Message = "Hello World "'Show it. MsgBox Message
Visual Basic IDE Title Bar Tool Box Menu Bar Form Layout Window Project Explorer Window Properties Window Form Window Project Window Integrated Development Environment (IDE)
Title bar, Menu bar …... Title Bar Menu Bar Standard Tool Bar
Tool Box image Text Box Command Button Option Button List Box Vscroll Bar Drive List Box Line Data Access File List Box Pointer Label Frame Check Box Combo Box Hscroll Bar Timer Directory List Box Shape Picture
Form Layout Window Project Explorer Window <ul><li>The Project Explorer window gives a list of the forms and modules that are part of the current project. </li></ul>To experiment with the Project Explorer window, click the Toggle Folders button . Notice that the folders are collapsed. To expand the folders, click the Toggle Folders button again. The Form Layout window allows you to position your form or forms with regard to the rest of the screen. It uses a graphical interface to guide you. To experiment with it, click the small image inside the small screen and drag to the upper left corner inside the small screen. Notice that the small image can move
Notice that the right section of the Standard toolbar displays the dimensions of the form.
Controls Label Displays text on a form Frame Serves as a container for other controls CheckBox Enables users to select or deselect an option ComboBox Allows users to select from a list of items or add a new value HscrollBar Allows users to scroll horizontally through a list of data in another control Timer Lets your program perform actions in real time, without user interaction
Controls DirListBox Enables users to select a directory or folder Shape Displays a shape on a form Image Displays graphics (images) on a form but can't be a container OLE Container Enables you to add the functionality of another Control program to your program PictureBox Displays graphics (images) on a form and can serve as a container TextBox Can be used to display text but also enables users to enter or edit new or existing text
Naming Convention Control Prefix Control Prefix Label lbl PictureBox pic Frame fra TextBox txt CheckBox chk CommandButton cmd ComboBox cbo OptionButton opt HscrollBar hsb ListBox lst Timer tmr VscrollBar vsb DirListBox dir DriveListBox drv Shape shp FileListBox fil Image img Line lin OLE Container Control ole Data dat