Controls in visual Basic

Visual basic as we discuss in introduction to visual basic is a graphical language or event driven language.In other language we take input only by mouse or keyboard but in visual basic we can take input not only by use mouse of mouse and keyboard but also with the help of controls.There are 21 instrisic controls in tool box by default.Other common control and active-x controls.Some instrinsic controls are:-
1. Pointer control
2.label control
3. Frame control
4.Text box
5. Picture box
6. Image box
7. List box
8.Combo box
9.command button
10. File
11.Drive list
12.Directory list
13.OLE control
Common control are:-
1.Image list
2.Status bar
3.Scroll bar
4.Progress bar
5.Tree view
6.List view
7.Tool bar
8.Cool bar etc.
There are some another user defined controls called active-x control.
Pointer control:-This control just for adjusting mouse pointer.Pointer style can be changed by this control.

Level control:-This control used to show static data which not participate in execution.Ex.As in form Name....... Is static data can be shown by level control.

Frame control:-Frame is called container control.Because it is used to place another control for better look.

Text Box:-It is also called edit control.We can perform editing,and it is also used to take input from user.

List box:-List box is used for display items.

Combo box:-Combo box is combination of edit control and list control.It also used to display list if item.
Three types of combo box available in visual basic:-
Simple combo box:-simple box has text box and list box and display items in a list at once.We can type in text box.

Dropdown combo box:-It show items in dropdown combo box means when user click on pointer arrow then list show.We can type in text box.

Dropdown list box:-Drop down list combo box show items in drop down list but in this type of cimbo box we can not type in text box.

Image box and picture box:-Image box and picture box used to display pictures.But picture box is called container for another control but image box not.Image box can be stretched but picture box not.Picture box shown at execution time but image box not.

File,drive list and directory list:-
File show list of files.Drive show folders which contain different files in single drive.And directory can have folder as well as files.

OLE:-It stand for object linking and embedding.

Common controls:-
Image list:With the help of image list we can show list of images by loading at once.

Status control:-Status bar show the status of open file or folder.Means at which row and column user write...etc

Progress bar:-Progress bar is used to show progress of application or program or downloading etc.It show by step by step increament of timer.Ex as show during internet servise.

Tree view:-Tree view is show to show items in a hierarchical structure.

List view:-List view is also used to show items ina list as icons.

Tool bar:-Tool bar contains tools means short cuts of menu options such as cut,copy,paste etc.

Cool bar:-Cool bar is also called container control which is used for place tool bar on it.
These are some common controls now inspite of these control there are also user defined control called active-x control.Active-x is a control which can we created by user for his own convenience means user can create a combination of two or more control at one place which he need again and again,inspite of creating all those controls for his projects separate of every time ,he can create his own control and use it when need.He not only use it for his own need but also can provided to another user when he add that control in tool box..How all these control works we discuss it soon.
Thanks.
Stay in touch.

Data types in Visual basic

This article is about data types used in visual basic.Data type is referred to as type of data which show the memory space taken by data.
friends,
As we study data types in other high level languages such as c and c++,in this language also same data type as well as some extra data types.

Variable:-
Memory location that hold data that can be changed during project execution are called variables.
or
We can say that a name assign to memory for store data is called variable.
Declaration of variable is of two types:-
1. Explicit
2.Implicit

Explicit:-As the type clause in the Dim statement allows to define the data type or object type of the variable.This is called explicit declaration.

Implicit:- When in vb encounters a new variable ,it assigns the default variable type &value.This is called implicit declaration..This is called implicit declaration.This is useful for user to control over variables.

Constant:- Location that hold data that can not change during execution are called constants.
Const keyword is used for declaration.
Ex. Const a as interger=10
If data type is not given then it is of type variant.
const is always declare globally.It can't declare in procedure.

Variant:- Variant data type means that when we not declare data type then by default it is of type variant .it is called variant because variable and constant change their appearance as needed for each situation.
But negetive point behind this is that it is less efficient than the other data types.It requires more memory space and operate less quickly than other.
Note:-Always try specify the data type.

There are another data types with their use.
1.Boolean :-
True and false.

2.Byte:-
It is used for a single ASCII character.

3.Currency:-
It is used for decimal fractions such as dollar & cents.

4.Date:-
It show 8 character date.

5.Double:-
It is for double precission floating point numbers with 14 digits of accuracy.

6.integer:-
For whole number with range -32768 to 32767

7.Long:-Provide larger whole numbers.

8.Single:-
Single precission floating point numbers with 6 digits of accuracy.

9.Variant:-
Convert from one type to another when needed.

10.string:-
Alphanumeric data,letters,digits and other characters.

Deciding which data type used when:-
The most common data types are string ,currency and integers.
1. When we require calculation we should use numeric(integer & currency)
2. No calculatio then should use string.
3. for decimal fraction in business application ,currency should use.
4. For scientific application single and double should use.
friends,
we will discuss some more other classification of data type in next article.
Thanks to being with us...........stay in touch.

Features of visual Basic

This article is about features of visual basic.In previous article introduction of visual basics we were discussed about basic introduction of visual basic its and various versions.features of visual basics include characterstics or functions provided by it.
friends,
Here i show you main features of visual basic which add glory to its existence and which highlighted its importance over other sowftware languages,

features of visual basic are as under:-

1. It has faster compiler.


2. It support active-x control:-

Active-x control are small program ,sometimes called add-ons that are based on internet.They can inhance browsing experience by allowing animation or it can help with task such as insalling security updates at microsoft updates.
It makes browsing more enjoyable by providing toolbars,stocks tickers,video animated content,and more.we can say that active-x is a technology used to add interactively two web pages.We can interactive controls to web pages.these control can be anything from a single push button to a complete spreadsheet.It works on certain browser as microsoft browser internet explorer recognise active-x control but netscape not.it is similar to Java applets.It outgrowth with two technologies:-
1.Object linking and embedding.
2.com(component object models.

3. It has new packages & development wizard


4. By default data types are variant

Variant data type here means for it change its appearance as needed for each situation.

5. It is plateform dependent language::-


6. It support graphical user interface.
   Main elements of GUI are:-
   1.Text Boxes.
   2.Label Boxes.
   3.Radio Buttons.
   4.Command Buttons.
   5.Frames.
   6.Scroll bars.
   It is itself is graphic and software developed by it is also graphical.
   
7. It is Object oriented.

There are fours types of modules used in visual basic :-
1.Class module.
2.Form module.
3.Active-x module.
4.Dupples module.
These four features shows that vb is object base language.
Member functions of oop's are called methods in vb.
Data members of oop's are called property in vb.
These are accessed by:-
objectname.method or property.

8. It can show static as well as dynamic array.


9. visual basic support data files as well as database.
   Data files are the program written in vb.
   Database can be :-
   1.Queries.
   2.Procedures.
   3.Tables.
   4.Indexes.
   5.Views.
   There are two types of data files:-
   1. Sequential files.
   2. Random files.
   Data files store in secondary storage.
   Database store in Ram.
   
10. Visual basic is rapid application development tool.

Because it is graphical user so rapid to draw.

11. It is case sensitive language.

friends,
This is all about features of visual basic .we will discuss more about visual basic in next article.
Thanks................stay in touch and give feedback .

Introduction to visual Basic

This article is about history of visual basic and its introduction.
Friends,
Visual basic is one of the most powerful software development language.Visual basic helps to create GUI application in the shorter time as compared to conventional languages such as C/C++,pascal etc.This language is object base and event driven language.It is only used for developing application software but not system software.
Origen
It is appeared in 1991 and developed by Microsoft corporation.

1. V.B 1.0 was released in 1991


2. V.B 2.0 was released in nov. 1992


3. V.B 3.0 was released in 1993


4. V.B 4.0 was released in 1995(it is 32 bit as well as 16 bit processor)


5. V.B 5.0 was released in 1997(32 bit,for 16 bit convert in V.b 4.0)


6. V.B 6.0 was released in 1998(web based application)

Visual basic operate on window environment.It is RAD(Rapid Application Development Tool)
Main features of Visual Basic

1. It has faster compiler


2. It support active x control


3. It allow database integration with wide variety of applications.


4. It has new package & development wizard


5. Additional internal capabilities.

Friends,
I will discuss more about V.B in next article .Upto then stay in touch..........
Thank you.

Basics of visual basic...........a dos based language

This article is about a high level language visual basic.This language is dos(Disk operating system) based basic language.Basic stand for Beginner all purpose symbolic instruction code.Before discuss about this language we should know what is programming?
friends,
As you know computer is a dump machine ,it has not its own brain.It is totally depend on instructions and code provided to it.Human has brain but computer has much more computation speed than human but it also require human assistance.Because it understand only electrical on and off state.Human provide instruction to it by the means of computer codes which help it for fast computation.this coding instruction is programming.
Visual Basic
Visual basic is a high level language which is evolved from earlier version of dos.
It is very easy programming language to learn.Different companies provide different versions for learning basic like QUICKBASIC,IBM BASIC etc.But mostly Micro soft visual basic is used.The resources related to this version is mostly available in the market.There are also many version of vb exist in market but visual basic 6 is mostly used in today.
visual basic is Visual and event oriented language.Many another languages are only text oriented language but it can work in graphical environment.In the old BASIC, you have to write program code for each graphical object you wish to display it on screen, including its position and its color. However, In VB , you just need to drag and drop any graphical object anywhere on the form, and you can change its color any time using the properties windows.
In Visual basic as user click randomly for any action so there are different subprograms are used for different task.
So friends,
It is something about this language.I will discuss more about this soon.....
Thanks for visit...........