Introduction to programming using Visual Basic 6

Introduction to Programming
Using Visual Basic 6.0

Why VB? Rationale…
 Easy for beginners to produce a workingEasy for beginners to produce a working
programprogram
 Capable of high end programsCapable of high end programs
 GraphicalGraphical
 OOP (for the most part)OOP (for the most part)
 AffordableAffordable
 Many free resources availableMany free resources available
2

The VB IDE
Menu bar
Tool box
Tool bar
Project
Window
View Code View Object
Project
Explorer
Window
Properties
Window
Immediate
Window
3

As in all WindowsAs in all Windows
applications, simplyapplications, simply
choose View from thechoose View from the
menu to view yourmenu to view your
different toolboxes,different toolboxes,
windows, etc. or towindows, etc. or to
remove them from theremove them from the
IDE.IDE.
View Menu
4

Objects
Every VB app has atEvery VB app has at
least one object – theleast one object – the
form.form.
Other objects are added atOther objects are added at design timedesign time byby
selecting the object from the toolbox andselecting the object from the toolbox and
drawing it on the form. A second way is todrawing it on the form. A second way is to
simply double-click the object and it willsimply double-click the object and it will
appear on the form.appear on the form.
5

Object Properties
All objects should be named. Each object has aAll objects should be named. Each object has a
prefix that is standard in the VB coding world.prefix that is standard in the VB coding world.
For example, the prefix for a form isFor example, the prefix for a form is frmfrm. See the. See the
VB help for a complete list.VB help for a complete list.
Objects have many properties that can be accessed atObjects have many properties that can be accessed at
design time or at run time.design time or at run time.
VB usesVB uses dot notationdot notation to access properties…forto access properties…for
example:example: lblMessage.Caption = “Welcome!”lblMessage.Caption = “Welcome!”
Object Property Property
Value
6

Events
AnAn event procedureevent procedure is a block of code thatis a block of code that
executes in response to an event. Aexecutes in response to an event. A useruser
eventevent is an action performed by the useris an action performed by the user
such as asuch as a mouse clickmouse click..
7

The Inevitable Hello World Program
We will work toWe will work to
create thecreate the
program shownprogram shown
at the side.at the side.
1.1. Open VB andOpen VB and
choose a New,choose a New,
Standard ExeStandard Exe
program.program.
8

Hello World
2.2. Name the formName the form
frmHelloWorldfrmHelloWorld
3. Type in the3. Type in the
Caption asCaption as
shown. Noteshown. Note
it change init change in
the title bar.the title bar.
9

Hello World
4.4. Save the project.Save the project.
Create a new folderCreate a new folder
and save your formand save your form
in.in.
5. A second dialog box will5. A second dialog box will
pop to ask for the Projectpop to ask for the Project
name…change it toname…change it to HelloHello
WorldWorld as shown to the rightas shown to the right
10

6.6. Add a labelAdd a label
object andobject and
resize itresize it
accordingly.accordingly.
7.7. Change theChange the
name toname to
lblMessage.lblMessage.
8.8. Change theChange the
Caption toCaption to
Welcome!Welcome!
Label Object
11

9. Choose the9. Choose the
FontFont
propertyproperty
and makeand make
your fontyour font
larger andlarger and
of aof a
differentdifferent
type.type.
Font Property
12

10. Choose the10. Choose the
AlignmentAlignment
propertyproperty
and Centerand Center
the labelthe label
Alignment Property
13

11.11. Add aAdd a
commandcommand
button bybutton by
doubledouble
clicking thatclicking that
object in theobject in the
toolbox.toolbox.
Move it asMove it as
shown.shown.
12.12. Name theName the
buttonbutton
cmdDisplaycmdDisplay
and changeand change
the caption tothe caption to
Display.Display.
Command Button
14

13.13. Add a buttonAdd a button
calledcalled cmdDonecmdDone
and change theand change the
caption tocaption to Done.Done.
Note: If you chooseNote: If you choose
to Copy andto Copy and
Paste a control,Paste a control,
you will get ayou will get a
message box re:message box re:
Control Array.Control Array.
Answer “NO” toAnswer “NO” to
this.this.
Done Button
15

We will begin codingWe will begin coding
with thewith the
cmdDone_ClickcmdDone_Click
event procedure.event procedure.
14. Double click the14. Double click the
Done button on theDone button on the
object. This willobject. This will
open up the codeopen up the code
editor window aseditor window as
shown. Type inshown. Type in
Unload Me.Unload Me.
Time to Code
16

Unload Me
Adding the code Unload Me to theAdding the code Unload Me to the
cmdDone_ClickcmdDone_Click event tells the computer thatevent tells the computer that
when the control namedwhen the control named cmdDonecmdDone is clicked, theis clicked, the
form (me)form (me) willwill unloadunload..
ToTo runrun your program, choose Run from the menu,your program, choose Run from the menu,
press F5, or click the Run button on the toolbar.press F5, or click the Run button on the toolbar.
Clicking the Done button should unload your form.Clicking the Done button should unload your form.
17

Display Button
The code for the Display button will make theThe code for the Display button will make the
Caption in the labelCaption in the label lblMessagelblMessage changechange
to “Hello, World”.to “Hello, World”.
15. Double click the Display button and type15. Double click the Display button and type
in the following code:in the following code:
lblMessage.Caption=“Hello,lblMessage.Caption=“Hello,
World”World”
Run your program and click theRun your program and click the
Done button.Done button.
18

Details – Default Buttons
It would be good if the user could simply hitIt would be good if the user could simply hit
the <Enter> key to have the message change.the <Enter> key to have the message change.
16. Choose the Display button, find the16. Choose the Display button, find the
DefaultDefaultproperty and set it to
True. Run the
program. Note the
dark outline around the
button indicating that it
is Default.
19

Details – Keyboard Access Keys
Another standard Windows feature is to beAnother standard Windows feature is to be
able to access a key using Alt-?. To createable to access a key using Alt-?. To create
this ability in your program, change thethis ability in your program, change the
Caption property to include anCaption property to include an &&..
Caption for Display - &Display
Caption for Done – D&one.
(You can’t have them both be a D
for the hotkey.
20

Moving Your Program and Creating
an exe.
Your program at this point will consist of threeYour program at this point will consist of three
files…files…
*.frm*.frm
*.vbw*.vbw
*.vbp*.vbp
You would need to transport all 3 of these to have itYou would need to transport all 3 of these to have it
work properly at a different location.work properly at a different location.
17. Create an exe by choosing File, Make17. Create an exe by choosing File, Make
Helloworld.exe. Choose your path. This one file,Helloworld.exe. Choose your path. This one file,
of course, will allow others to run your program,of course, will allow others to run your program,
but not to edit it.but not to edit it. 21

Colors
We can alter the look of your formWe can alter the look of your form
with colors and graphics.with colors and graphics.
18.18. Select lblMessage. ChooseSelect lblMessage. Choose
the Backcolor property, thenthe Backcolor property, then
Palette.Palette.
Select a color of your own choice.Select a color of your own choice.
19.19. Do the same for the Forecolor.Do the same for the Forecolor.
22

Colors on Buttons
You change the color of a button’sYou change the color of a button’s
background, but first you must set it’sbackground, but first you must set it’s
Style property to Graphical.Style property to Graphical.
20.20. Choose the Display button, then changeChoose the Display button, then change
the Backcolor and the Style property.the Backcolor and the Style property.
Note that there is no Forecolor…the fontNote that there is no Forecolor…the font
stays blackstays black..
23

Graphics
We can also add graphics to some objects.We can also add graphics to some objects.
21. Select the Picture property of
the Form, then choose an
image. This one is at
g:klimackimagesbonnell.
Change the file type to All
Files if nothing is showing
up.
22. Change your Done button picture property remembering to
change the Style to Graphical. 24

Message Boxes
23.23. In your code for the Done button, add thisIn your code for the Done button, add this
line:line:
MsgBox "Have a good day!", vbOKOnly, "ByeMsgBox "Have a good day!", vbOKOnly, "Bye
Bye"Bye"
25

Comments
Adding comments in VB is done by prefixing yourAdding comments in VB is done by prefixing your
statement with an apostrophe. For example:statement with an apostrophe. For example:
‘‘this is a comment and will be ignored by the computerthis is a comment and will be ignored by the computer
Comments turn green when typed correctly.Comments turn green when typed correctly.
24.24. At the top of your program, add comments with yourAt the top of your program, add comments with your
name, date, and project info as such:name, date, and project info as such:
‘‘Cheryl KlimackCheryl Klimack
‘‘Hello World projectHello World project
‘‘Oct 24 2003Oct 24 2003
Run your program. We are done!Run your program. We are done!
26

Pizza Project
We will create theWe will create the
project shown toproject shown to
the left withthe left with
checkboxes,checkboxes,
option buttons,option buttons,
textboxes,textboxes,
message boxes,message boxes,
command buttonscommand buttons
and labels.and labels.
28

1.1. Create a new project by firstCreate a new project by first
removing the current project.removing the current project.
Save as Pizza.Save as Pizza.
2.2. Add a label and format it asAdd a label and format it as
you desire.you desire.
3.3. Add an image control andAdd an image control and
name itname it imgPizza.imgPizza. TheThe
image seen here is found atimage seen here is found at
G:klimackimages.G:klimackimages.
Note: to resize an image on yourNote: to resize an image on your
form, you must set the Stretchform, you must set the Stretch
property to True.property to True.
29

4.4. Add and nameAdd and name
labels andlabels and
textboxes totextboxes to
correspond to thecorrespond to the
figure at thefigure at the
right. Don’tright. Don’t
worry aboutworry about
lining them uplining them up
perfectly yet.perfectly yet.
lblName
lblPhone
txtPhone
txtName
Choose the Text property and
delete it’s contents to remove
Text1 from the text boxes.
30

Aligning
You can line up objects on your form evenlyYou can line up objects on your form evenly
by selecting them (holding down the shiftby selecting them (holding down the shift
key allows multiple selections) and thenkey allows multiple selections) and then
choosing Format, Align, etc. Notice thechoosing Format, Align, etc. Notice the
other options under the Format menu.other options under the Format menu.
5.5. Line up your labels and text boxes.Line up your labels and text boxes.
6.6. Choose both labels and text boxes at theChoose both labels and text boxes at the
same time, then select Font and makesame time, then select Font and make
them all 10 or 12 point.them all 10 or 12 point.
31

Frames
Frames are used as containers for otherFrames are used as containers for other
controls. Usually groups of option buttonscontrols. Usually groups of option buttons
are placed in frames.are placed in frames.
7. Add a frame named fraSize.
8. Make the Caption Size.
32

Option Buttons in Frame
These are used when only one button of a groupThese are used when only one button of a group
should be selected. For example, a pizza sizeshould be selected. For example, a pizza size
choice cannot be both large and medium atchoice cannot be both large and medium at
the same time.the same time.
9. Select (but do not
double click) the
Option button control.
Draw 3 buttons inside
of the frame. Name
them optSmall,
optMedium, and
optLarge.
10. Line them up
and make the
same size. Make
their spacing
equal as well.
33

Options on Form
Options on a form but not in a frame function as aOptions on a form but not in a frame function as a
group.group.
11. Add options for
Pickup and Delivery
as shown. Set the
Value for Pickup to
True
Note: Run the program and
experiment with the buttons.
If you can select 2 in one
group, one of them doesn’t
belong. Delete it and
recreate it.
34

Multiline Textboxes with Scroll Bars
12. Add a label12. Add a label
(lblAddress) for(lblAddress) for EnterEnter
AddressAddress and a textboxand a textbox
(txtAddress) for the(txtAddress) for the
contents of thecontents of the
address. Make theaddress. Make the
Multiline propertyMultiline property
True, and setTrue, and set
Scrollbars to Both.Scrollbars to Both.
35

Checkboxes
Checkboxes allow the user to select (orCheckboxes allow the user to select (or
deselect) an option. Any number ofdeselect) an option. Any number of
checkboxes in a group may be selected. Ifcheckboxes in a group may be selected. If
selected, it’s value is vbChecked, otherwiseselected, it’s value is vbChecked, otherwise
it is vbUnchecked.it is vbUnchecked.
13. Add a frame for
Toppings
(fraToppings).
14. Add the checkboxes
indicated
(chkPepperoni, etc.) 36

Order and Cancel Buttons
15. Add an Order15. Add an Order
and Canceland Cancel
button as shownbutton as shown
in the figure atin the figure at
the right. Makethe right. Make
the Order buttonthe Order button
Default. AddDefault. Add
hotkey access.hotkey access.
37

Time to Code!
The specs for this program state that the orderThe specs for this program state that the order
can be cancelled at any time. After ordercan be cancelled at any time. After order
placement, a message box will appearplacement, a message box will appear
asking the user to verify the order asasking the user to verify the order as
indicated. If it is verified another messageindicated. If it is verified another message
box will indicate this.box will indicate this.
38

Enabling and Disabling
It is a good idea to not let the user makeIt is a good idea to not let the user make
inappropriate choices if at all possible.inappropriate choices if at all possible.
Disable any options that are not applicable at theDisable any options that are not applicable at the
current time, and enable them whencurrent time, and enable them when
appropriate.appropriate.
16. Select all the checkboxes at once and set the16. Select all the checkboxes at once and set the
Enabled property to False. Run the program.Enabled property to False. Run the program.
39

Enabling Controls
It would be appropriate for these checkboxes to beIt would be appropriate for these checkboxes to be
enabled after choosing a pizza size.enabled after choosing a pizza size.
17.17. Double click optSmall, and add this code to theDouble click optSmall, and add this code to the
procedure.procedure.
chkPepperoni.enabled=truechkPepperoni.enabled=true
Run the program. Click on Small and PepperoniRun the program. Click on Small and Pepperoni
should become enabled.should become enabled.
18. Enable each of the checkboxes in the same18. Enable each of the checkboxes in the same
manner.manner.
40

Copy and Pasting Code
19. The code for19. The code for
Medium and LargeMedium and Large
will be the same as itwill be the same as it
is for Small, so youis for Small, so you
can copy and paste itcan copy and paste it
into thoseinto those
procedures. Nowprocedures. Now
choosing any of thechoosing any of the
sizes will enable thesizes will enable the
checkboxes.checkboxes.
Choose the
procedures
here.
41

The Address Box
We don’t need the addressWe don’t need the address
box if the order is forbox if the order is for
Pickup, so it should notPickup, so it should not
be visible until thebe visible until the
Delivery button isDelivery button is
selected.selected.
20. Choose lblAddress and20. Choose lblAddress and
txtAddress and maketxtAddress and make
Visible = false in theVisible = false in the
properties window.properties window.
42

Delivery Option Button
If you choose the Delivery option, these two controlsIf you choose the Delivery option, these two controls
((lblAddresslblAddress andand txtAddress)txtAddress) should become visibleshould become visible
and the cursor should move to the txtAddress box,and the cursor should move to the txtAddress box,
waiting for input.waiting for input.
21. Add the following to the optDelivery_click21. Add the following to the optDelivery_click
txtAddress.Visible = TruetxtAddress.Visible = True
lblAddress.Visible = TruelblAddress.Visible = True
txtAddress.SetFocustxtAddress.SetFocus
43

Pickup Option Button
Just as Delivery should make the Address infoJust as Delivery should make the Address info
visible, Pickup should make themvisible, Pickup should make them
invisible.invisible.
22.22. Add the following to the optPickup_clickAdd the following to the optPickup_click
procedure:procedure:
txtAddress.Visible = falsetxtAddress.Visible = false
lblAddress.Visible = FalselblAddress.Visible = False
44

Cancel Button
If the user clicks theIf the user clicks the
Cancel button, allCancel button, all
the info currentlythe info currently
entered shouldentered should
disappear and thedisappear and the
form reset to theform reset to the
initial screen.initial screen.
23.23. Get to theGet to the
cmdCancel_clickcmdCancel_click
procedure and enterprocedure and enter
the following linesthe following lines
of code:of code:
'clear the text boxes
txtName.Text = ""
txtPhone.Text = ""
txtAddress.Text = ""
45

Canceling, continued
'clear'clear the size optionsthe size options
optSmall.Value = FalseoptSmall.Value = False
optMedium.Value =optMedium.Value =
FalseFalse
optLarge.Value = FalseoptLarge.Value = False
'set the pickup option'set the pickup option
optPickup.Value = TrueoptPickup.Value = True
'clear the checkboxes
chkPepperoni.Value = vbUnchecked
chkSausage.Value = vbUnchecked
chkMushrooms.Value = vbUnchecked
chkGreenPeppers.Value = vbUnchecked
chkExtraCheese.Value = vbUnchecked
chkOnions.Value = vbUnchecked
46

Canceling, continued
Last of all, disable the checkboxes again and set theLast of all, disable the checkboxes again and set the
focus to txtName.focus to txtName.
'disable the checkboxes
chkPepperoni.Enabled = False
chkSausage.Enabled = False
chkMushrooms.Enabled = False
chkGreenPeppers.Enabled = False
chkExtraCheese.Enabled = False
chkOnions.Enabled = False
‘set focus
txtName.SetFocus
47

Global Variables
We are going toWe are going to
use someuse some
GlobalGlobal
variables forvariables for
this program.this program.
24. Add the lines24. Add the lines
shown to yourshown to your
program.program.
These variablesThese variables
can be used bycan be used by
all theall the
procedures.procedures.
49

Constants
Every time the user selects or de-selects a topping,Every time the user selects or de-selects a topping,
the topping price must change. In this case,the topping price must change. In this case,
toppings are 75 cents each.toppings are 75 cents each.
25. Constants should be declared before variables,25. Constants should be declared before variables,
and these are global as well, so add themand these are global as well, so add them
BEFORE the 2 global variables you just added.BEFORE the 2 global variables you just added.
50

Topping Price
We need to ADD to the curToppings every time aWe need to ADD to the curToppings every time a
new topping is selected, and SUBTRACT everynew topping is selected, and SUBTRACT every
time one is de-selected.time one is de-selected.
26.26. InIn eacheach chk procedure, add code similar to thechk procedure, add code similar to the
following, changing the Pepperoni to thefollowing, changing the Pepperoni to the
appropriate topping.appropriate topping.
If chkPepperoni.value=vbChecked thenIf chkPepperoni.value=vbChecked then
curToppings=curToppings +curToppings=curToppings +
curToppingPricecurToppingPrice
ElseElse
curToppings=curToppings –curToppings=curToppings –
curToppingPricecurToppingPrice
51

The Immediate Window
For testing purposes, you canFor testing purposes, you can ViewView the Immediatethe Immediate
window and see the results of thewindow and see the results of the debug.printdebug.print
itemitem statement that can be included in the code.statement that can be included in the code.
Add this line to eachAdd this line to each chk procedurechk procedure..
Debug.print “Toppings =“Debug.print “Toppings =“
;curToppings;curToppings
When you run your program, select and de-selectWhen you run your program, select and de-select
different checkboxes and watch the results in thedifferent checkboxes and watch the results in the
immediate window.immediate window.
52

Debug.Print
statements
Results of
Debug.print
53

Size Price
The size price depends upon whicheverThe size price depends upon whichever
option is selected. Each option procedureoption is selected. Each option procedure
needs to have code similar to the following:needs to have code similar to the following:
curSize = curSmallcurSize = curSmall ‘add to‘add to
optSmalloptSmall
curSize=curMediumcurSize=curMedium ‘ add to‘ add to
optMediumoptMedium
curSize=curLargecurSize=curLarge ‘add to‘add to
optLargeoptLarge
54

Total Price
We need to calculate the total due as anWe need to calculate the total due as an
addition of curSize and curToppings.addition of curSize and curToppings.
27.27. Declare curTotal as a global variable ofDeclare curTotal as a global variable of
type currency.type currency.
Private curTotal as currencyPrivate curTotal as currency
in the General section.in the General section.
55

Calculating the Total
To calculate curTotal, we need to add a line to everyTo calculate curTotal, we need to add a line to every
procedure that affects the price.procedure that affects the price.
curTotal=curToppings + curSizecurTotal=curToppings + curSize
28.28. Add this line to all the options for size and theAdd this line to all the options for size and the
checkboxes. (Thank goodness for copy and paste!)checkboxes. (Thank goodness for copy and paste!)
If you change your Debug.Print statement as shown, youIf you change your Debug.Print statement as shown, you
can watch the totals as you run your program. Usecan watch the totals as you run your program. Use
Edit, Replace to do this.Also, copy and paste it toEdit, Replace to do this.Also, copy and paste it to
your options after the lines that calculate theseyour options after the lines that calculate these
totals.totals.
29.29. Debug.Print "Toppings =";Debug.Print "Toppings =";
curToppings; "Total is"; curTotalcurToppings; "Total is"; curTotal
56

Verifying the Order
Now that we have the totals workingNow that we have the totals working
properly, we need to manipulate someproperly, we need to manipulate some
strings.strings.
We want a message box similar to the figureWe want a message box similar to the figure
to appear when the Order button isto appear when the Order button is
clicked.clicked.
30.30. Declare a global variable to contain aDeclare a global variable to contain a
string representing the size of the Pizza.string representing the size of the Pizza.
Private strSize as stringPrivate strSize as string
57

strSize
31.31. In each of the procedures for the sizeIn each of the procedures for the size
options, add a line to assign a string tooptions, add a line to assign a string to
string size that corresponds with the size.string size that corresponds with the size.
For example, in optSmall add:For example, in optSmall add:
strSize=“Small”strSize=“Small”
In optMedium, addIn optMedium, add strSize=“Medium”strSize=“Medium” &&
in optLarge addin optLarge add strSize=“Large”.strSize=“Large”.
58

Check for Required Input
32.Add the32.Add the
followingfollowing
code to verifycode to verify
that nothat no
requiredrequired
options oroptions or
textboxes aretextboxes are
left blank.left blank.
We do notWe do not
have time tohave time to
validate thevalidate the
input today.input today.
Dim blnValidData As Boolean
'error checking
blnValidData = False
If txtName.Text = "" Then
MsgBox "Invalid name"
txtName.SetFocus
ElseIf txtPhone.Text = "" Then
MsgBox "Invalid phone"
txtPhone.SetFocus
‘to be continued
59

Run yourRun your
project andproject and
click the orderclick the order
button withbutton with
some textsome text
boxes leftboxes left
blank.blank.
ElseIf strSize = "" Then
MsgBox "Invalid size"
optSmall.SetFocus
ElseIf optDelivery.Value = True And
txtAddress = "" Then
MsgBox "Invalid address"
txtAddress.SetFocus
Else
blnValidData=True
End If
60

Create a Toppings List
Once we have validated entry in each requiredOnce we have validated entry in each required
control, we can create a toppings list. Note thecontrol, we can create a toppings list. Note the
indenting.indenting.
33.
'list toppings in a string
If blnValidData = True Then
If chkPepperoni.Value = vbChecked Then
strToppings = strToppings & vbCrLf &
"Pepperoni"
End If
If chkSausage.Value = vbChecked Then
strToppings = strToppings & vbCrLf &
"Sausage"
vbCrLf – carriage return,
line feed
&
concatenate61

Toppings, continued
Copy and paste the if …then statement forCopy and paste the if …then statement for
Pepperoni 5 times to create appropriate ifPepperoni 5 times to create appropriate if
statements for all of the toppings, as shownstatements for all of the toppings, as shown
for Sausage.for Sausage.
A message box can be a quick test to see ifA message box can be a quick test to see if
this works:this works:
MsgBox strToppings 'test toppingsMsgBox strToppings 'test toppings
stringstring
Delete this line once testing is completed.Delete this line once testing is completed. 62

Delivery Method
The following code can be used to determine theThe following code can be used to determine the
appropriate string for the method of delivery:appropriate string for the method of delivery:
34. Declare a variable strDeliveryMethod as string34. Declare a variable strDeliveryMethod as string
in the Order procedure. Then add the following toin the Order procedure. Then add the following to
the bottom of the procedure.the bottom of the procedure.
'check for delivery or pickup'check for delivery or pickup
If optDelivery.Value = True ThenIf optDelivery.Value = True Then
strDeliveryMethod = "Delivery"strDeliveryMethod = "Delivery"
ElseElse
strDeliveryMethod = "Pickup"strDeliveryMethod = "Pickup"
End IfEnd If
63

Message Boxes Revisited
There are different parameters youThere are different parameters you
can use with Message Boxes.can use with Message Boxes.
See the Help for a complete list.See the Help for a complete list.
We are going to ask the user toWe are going to ask the user to
click Yes or No to confirm theclick Yes or No to confirm the
order. We want their response toorder. We want their response to
be stored so we can act upon it.be stored so we can act upon it.
If it is yes, the form should printIf it is yes, the form should print
and clear. If no, the message boxand clear. If no, the message box
should simply disappear andshould simply disappear and
allow the user to make theallow the user to make the
required changes.required changes.
64

Message Box String
The following code will output a message box withThe following code will output a message box with
the appropriate strings and the Yes/No buttons.the appropriate strings and the Yes/No buttons.
35. First, declare a variable in the declaration section35. First, declare a variable in the declaration section
of the procedure.of the procedure.
Dim intOrderCorrect as IntegerDim intOrderCorrect as Integer ‘holds‘holds
yes/no response from useryes/no response from user
65

Msgbox()
intOrderCorrect = MsgBox("Order for " & txtNameintOrderCorrect = MsgBox("Order for " & txtName
& vbCrLf _& vbCrLf _
& strSize & "Pizza for " & strDeliveryMethod && strSize & "Pizza for " & strDeliveryMethod &
" with" _ & vbCrLf & strToppings & vbCrLf &" with" _ & vbCrLf & strToppings & vbCrLf &
vbCrLf & _vbCrLf & _
"Total = " & Format(curTotal, "currency") & _"Total = " & Format(curTotal, "currency") & _
vbCrLf & vbCrLf & _vbCrLf & vbCrLf & _
"Is this order correct?", vbYesNo, "Verify"Is this order correct?", vbYesNo, "Verify
Order")Order") _
at the end of a line means that _
the code is continued _
on the next line even though _
the statement is not finished.
66

vbYes, vbNo
If the order is correct, print the form and clearIf the order is correct, print the form and clear
it (the same as Canceling).it (the same as Canceling).
If intOrderCorrect = vbYesIf intOrderCorrect = vbYes
ThenThen
Me.PrintFormMe.PrintForm
Call cmdCancel_ClickCall cmdCancel_Click
End ifEnd if
If the order is not correct, do nothing to theIf the order is not correct, do nothing to the
program.program. 67

Conclusion
Thank you for attending this workshop.Thank you for attending this workshop.
Available on-line in zipped format is:Available on-line in zipped format is:
 This presentationThis presentation
 Hello World program sourceHello World program source
 Pizza sourcePizza source
 Source for the simple programs included in yourSource for the simple programs included in your
packagepackage
69

Introduction to programming using Visual Basic 6

Recommended

More Related Content

What's hot (20)

Viewers also liked (20)

Similar to Introduction to programming using Visual Basic 6 (20)

More from Jeanie Arnoco (20)

Recently uploaded (20)

Introduction to programming using Visual Basic 6

Editor's Notes