Basics of Visual FoxPro Programming

The Basics Of Visual FoxPro

Objectives:

• To be able to give basic information about FoxPro

Environment.

• To give an overview about basic VFP commands.

• To give an overview about basic VFP controls.

• To give an overview about basic VFP codes.

What To Learn in Visual Fox Pro

• Working With Command Window– Creating a New Table– Modify the Structure of a Table– Displaying and Editing Data

• Append Command• Browse Command• Replace Command

What To Learn in Visual Fox Pro cont.

• Delete and Recall Command– Pack Command– Zap Command– Recall Command

• Run Command• Set Default


Creating Control Objects

ProjectDatabaseTableFormReportMenu


Building Control Objects and its Properties

TextboxCommand ButtonOption GroupCheck BoxCombo BoxList BoxPage frameImage frameTimer


Basic Codes of FoxPro

AddSaveDeleteSearchNext ButtonBack ButtonTimer

Working with Command Window

The Command window is a Visual FoxPro system window. When you

choose menu commands, Visual FoxPro language commands are echoed in

the Command window.


Creating New Table

Syntax :create <table name>

To create a table file from command window type the

word CREATE followed by the name of the table file, and

press Enter key.


Modify the Structure of a Table

Syntax:Modify Structure

From the command window we can modify the structure by

typing the MODIFY STUCTURE command.


Displaying and Editing Data

Working from the command window, we can USE a table and then type one of the following:

•APPEND to display the table in Append mode.

•BROWSE to display the table in browse mode.

•REPLACE to change the contents in more than one record.



APPEND - This command is used to add records to the active database file.

Syntax:AppendAppend Blank

APPEND Blank - will add a blank record at the bottom of the screen.



Browse - This is a powerful editing command provide us facility to edit records horizontally with

showing us multiple records at a time.

Syntax:Browse



Replace - This is a powerful editing

command. This is used to replace a new

value in a field with or without a condition.

Syntax:Replace <field> with <expr1>


Delete and Recall Command

Replace - This is a powerful editing

command. This is used to replace a new

value in a field with or without a condition.

Syntax:Replace <field> with <expr1>



Pack - This command is used to physically remove

all those records whichwas marked for deletion.

Syntax:Pack



Zap- This command is used to erases all records of

active databaseexcept its structure.

Syntax:Zap



Recall- This command is used to unmark the

specified record which wasmarked for deletion.

Syntax:Recall


Run command

We can execute any DOS command or non Visual

FoxPro program without quitting from Visual FoxPro.

Syntax:Run [/n]


Set Default

Visual FoxPro uses its default drive and directory

forcreating files, unless we specify the path separately.

Syntax:Set Default To [cPath]

Creating Control Object

Project

From the menu click File

Select New

Select Project then New File


Project Manager


Table


Select New

Select Table then New File


Table


Form


Select New

Select Form then New File


Form


Report


Select New



Report


Menu


Select New



Menu

Building Control Objects

Textbox Option ButtonCommandButton

CommandGroup

Combo Box

Check Box

Image

List Box Timer

Page Frame

Fig.1.1 Form Controls of VFP

Building Control Object

Text Box

The text box is the basic control that allows users to add or edit data in a Character, Numeric, or Date

field in a table.


Text Box Properties

Alignment: center

PasswordChar: *

BackStyle: 0-TransparentBorderStyle: 0-None


Command Button

is typically used to start an event that performs an action such as closing a form, moving to a different

record, printing a report, and so on.


Command Button Properties

Caption: Save

Picture:


Option Group

You can use a group of option buttons to provide a selection of predetermined choices.


Option Group Properties

Value =:0

BackStyle: 0- TransparentBorderStyle: 0- None

Caption: Yes/No


Check Box

You can use a check box to switch between three states, True (.T.), False (.F.), and Null

(.NULL.).


Check Box


Combo Box

displays a list of items that you can choose an item from.


List Box

List boxes provide the user with a scrollable list that contains a number of options or pieces of

information.


Page Frame

A page frame is a container object that contains pages, which can contain controls.


Image

is a graphical control that displays bitmaps that can't be changed directly.


Timer

A typical use for the timer is checking the system clock to determine if it is time to run a program or

application.

Basic Codes of Fox Pro

ADD

select item2append blankthisform.txticode.setfocusthisform.refresh


Save

With thisformSelect item2Append blankReplace icode with thisform.txtcode.valueThisform.refreshendwith


Delete

WITH thisformselect item2 deletethisform.refreshENDwith


Search

LOCATE for Icode=ALLTRIM(thisform.textsearch.value)IF FOUND() thenMESSAGEBOX("Icode found")thisform.txtIcode.Value=Icodethisform.txtScode.Value=Scodethisform.txtDescri.Value=Descrithisform.txtPrice.Value=Pricethisform.search.Value=""ELSE MESSAGEBOX("Icode not Found")ENDIFthisform.Refresh


Next Button

select item2if !eof() thenskip+1thisform.refreshelsemessagebox("end of Records")goto topthisform.refreshendif


Back Button

select item2if !bof() thenskip-1thisform.refreshelsemessagebox("beggining of Records")goto topthisform.refreshendif

Simple Activity

1. Create new project and name it pos2. Create form name as activity3. Create table name as Item4. Input fields:

1. Icode character 32. Scode character 23. Descri character 154. Price numeric 4 decimal: 2

3. Design the GUI4. Command buttons:

1. Add2. Save3. Search4. Next5. Back

5. Place a grid that displays the added item6. Also place a search box for searching item code

Basics of Visual FoxPro Programming

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