Visual Basic Lesson 2 and 3

8/11/2019 Visual Basic Lesson 2 and 3

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Steps in Writing Visual Basic Projects

1. Create the user interface.2. Set the properties.

3. Write the Basic code.


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Step 2 Set the properties.

Toolbox

FORM

PROPERTYcharacteristic of an object.(color, size, background)


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PROPERTIES WINDOWdisplays attribute of thecurrently selected component (form/control).

PropertyName

PropertyValue


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Name property willbe used to refer to the

control in the Visual

Basic code.

Caption property tells what the user

will see on the form


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Naming Rules and Conventions for Objects

The Naming Rules

- Begin with a letter (40 characters in length)

- Name can contain letters, digits and

underscores only

- Do not include a space, punctuation marks andother special characters

Examples:

Kagitingan 3KagitinganKalayaan_3 _Kalayaan3 Kamalayan2012 Katarungan 2012

Katarungan! Kagitingan_&2012


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Naming Rules and Conventions for Objects

The Naming Conventions

- Begin the name with a lowercase three-letter prefix

(three-letter prefix identifies the object type)

- Capitalize the first character after the prefix- For names with multiple words, capitalize each

word in the name.

Examples:

lblKagitingancmdPrintTheForm


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-joining strings of text

Use an ampersand (&) precededand followed by a space between

two strings


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Steps in Writing Visual Basic Projects

1. Create the user interface.2. Set the properties.

3. Write the Basic code.


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-the statement that carriesout the action when the

event is triggered.

End

lblDisplay.Caption=Hello World

PrintForm

- the users action

cmdDisplay_Click

cmdCalculate_DblClick


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- adding a code in anevent


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EVENT DESCRIPTION

Activate This event occurs when forms get a focus.

Click This event occurs when the user click anywhere on the formor control.

Initialize This event occurs when the form is first generated.

Load This event occurs when the form is loaded into thecomputers memory and displays on the screen.

Dblclick This event occurs when the user double-clicks the form orcontrol.

Deactivate This event occurs when another form gets the focus.

Unload This event occurs when the form is terminated from thecomputers memory.

Resize This event occurs when the user changes the size of a form.

Change This occurs when the user changes the text inside a textbox.


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- a section in the code window

that holds assignmentstatements for a control toperform a specific task or action.

Private Sub cmdPushMe_Click ()


End Sub


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- displays the name of the control

that will trigger the event

- specifies the type of event for thecontrol


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Private Sub cmdPushMe_Click ()Display the caption Hello World in the label


End Sub

Private Sub cmdExit_Click ()

Exit the project

End

End Sub


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Private Sub cmdCalculate_Click ()

Calculate the price and discountDim intQuantity As Integer

Dim curPrice As Currency

Dim curExtendedPrice As Currency

Dim curDiscount As Currency

Dim curDiscountedPrice As Currency

Const curDiscountRate As Currency = 0.15

Convert input values to numeric variablesintQuantity = Val(txtQuantity.Text)

curPrice = Val(txtPrice.Text)

Calculate valuescurExtendedPrice = intQuantity * curPrice

curDiscount = curExtendedPrice * curDiscountRate

curDiscountedPrice = curExtendedPricecurDiscount

End Sub


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Private Sub cmdExit_Click ()

Exit the project

End

End Sub

Date: August 2, 2012

Programmer: (your name)

Description: This project demonstrates the use of

variables, constants, and calculations

Visual Basic Lesson 2 and 3

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Transcript of Visual Basic Lesson 2 and 3