Port Said International Schools – National Section
Better education for future generations
Revision Handout
Grade: 10
Loops & condition statements
1. For …Next: Used to repeat some commands for a specific number of times
Example:
Dim x As Integer = 1960
For x = 1970 To 2013 Step 2
ListBox1.Items.Add(x)
Next
 x variable is declared in the public section, and we’ve set an initial value of 1960 for it.
 We’ve set another initial value for it in the For… Next loop.
 Step is used to determine the incrementing value (in this case it’s 2), so we’ll have
these items in the ListBox1 (1970 – 1972 – 1974 – 1976 – 1978 - …………2010 – 2012)
 Notice that 2013 is NOT included because we add 2 each time until we reach 2013 or
less.
=================================================================
2. If … Then … Else.
If txt_UserName.Text = "Ahmed" And txt_password.Text = "123456" Then
Form1.Show()
Else
MsgBox("The username or password is not valid", vbOKOnly + vbCritical,
"Invalid User name or Password")
End If


I used compound condition here (Username = Ahmed And Password = 123456), both
of them must be evaluated to True.
I used the MsgBox( ) Function in the else statement to display a message error for the
user
Functions in VB

Visual Basic functions are:
1) MsgBox( ): used to display message box to the user, it takes 4 parameters(The
message that will appear in the dialog box – buttons – Icon - Title), only the
message is required.
Example:
Dim answer As Byte
answer = MsgBox("Are you sure ?", vbYesNo + vbQuestion, "Confirm")
answer is used to declare a variable to save the msgbox result in it.
The message is “Are you sure?”.
The buttons are “vbYesNo”.
The Icon is “vbQuestion”.
The title is “Confirm”.
2) Rnd: Used to create random numbers between 0 and 1.
Example:
Randomize()
MsgBox(Rnd())


Randomize( ) is used to randomize the random numbers, so each time you run the
program you’ll get different numbers, if you don’t use it, each time you run the
program you’ll get the same sequence of numbers.
I used the Msgbox( ) function to show the result of the Rnd function.
Port Said International Schools – National Section
Revision Handout
Better education for future generations
Grade: 10
 Size Mode property of the pictureBox has four options:
1. Zoom: is used to fit the image inside the border of the picture box while
maintaining the aspect ratio “The ratio of the width to the height”.
2. Stretch image: is used to fit the image inside the border of the picture box
without maintaining the aspect ratio “The ratio of the width to the height”.
3. Auto size: is used to enlarge or shrink the picture box control to the image size.
4. Normal: is used for put the image with its actual size in the control and hide
part of it or display a part of the picture box background according to the
image size – the image upper left corner will be aligned to the control upper
left corner.
5. Center image: just like normal put it will center the image in the picture box
control.
 image size and image bit depth properties of the image list:
1. Image size: is used to change the sizes of the images that are imported to this
image list. Maximum value is (256, 256).
2. Bit depth: is used to change the sizes of the images that are imported to this
image list. Maximum value is (Depth32Bit).
Please pay much attention to the controls names, you’ve to
follow the naming conventions, you can see examples of
that in the accompanied code.
Please check the programs you've taken
with this revision handout, and read the
comments very carefully.
Port Said International Schools – National Section
Revision Handout
Better education for future generations
Grade: 10
Multiplication Table:
Public Class Form1
Dim fnum, maxnum As Integer
Private Sub btn_ShowTable_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btn_ShowTable.Click
fnum = Val(txt_FirstNumber.Text)
'getting the value of the first text box and
assign it to the fnum variable
maxnum = Val(txt_MaxNumber.Text)
'getting the value of the second text box
and assign it to the max variable
Dim result As Integer
For index As Integer = 1 To maxnum
result = fnum * index
'getting the multiplication results
lb_Table.Items.Add(fnum & " * " & index & " = " & result)
'I'm displaying here the multiplication table
'lb_Table.Items.Add("Ramy")
'we can display my name as many times as the number of
the iterations
Next
End Sub
Private Sub btn_Clear_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btn_Clear.Click
lb_Table.Items.Clear()
'clearing the content of the list box
txt_FirstNumber.Clear()
'clearing the content of the first text box
"txt_FirstNumber"
txt_MaxNumber.Text = ""
'another way to clear a text box
End Sub
Private Sub btn_Exit_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btn_Exit.Click
End
'Exit the project
End Sub
End Class
Picture Random Position:
Public Class Form1
Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs)
Handles Timer1.Tick
Randomize()
picB_kodu.Top = Rnd() * 180
'used to get random number between 0 and 180
picB_kodu.Left = Rnd() * 175
End Sub
Private Sub btn_hide_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btn_hide.Click
picB_image.Visible = False
'this button is used to hide the picture box
End Sub
Private Sub btn_show_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
If picB_image.Visible = True Then
'if the image is displayed
picB_image.Visible = False
'hide it
Else
'if the image is hidden
picB_image.Visible = True
'show it
End If
'For more details about the size mode of the picture box, please check to the handout.
'For more details about the image size and image bit depth properties of the image list,
'please check the handout.
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btn_show.Click
picB_image.Visible = True
'this button is used to show the picture box
End Sub
End Class
Port Said International Schools – National Section
Revision Handout
Better education for future generations
Grade: 10
Flags:
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
PictureBox1.Image = ImageList1.Images(1)
'getting the image from the image
list by its index
PictureBox2.Image = Nothing
'put nothing in the image property
of the picture box.
PictureBox3.Image = Nothing
'put nothing in the image property
of the picture box.
'PictureBox1.Visible
picture by using the visible
'PictureBox2.Visible
picture by using the visible
'PictureBox3.Visible
picture by using the visible
= True
property
= False
property
= False
property
'another way to show and hide the
'another way to show and hide the
'another way to show and hide the
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button2.Click
PictureBox1.Image = Nothing
PictureBox2.Image = ImageList1.Images(0)
PictureBox3.Image = Nothing
'PictureBox1.Visible = False
'PictureBox2.Visible = True
'PictureBox3.Visible = False
End Sub
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button3.Click
PictureBox1.Image = Nothing
PictureBox2.Image = Nothing
PictureBox3.Image = ImageList1.Images(2)
'PictureBox1.Visible = False
'PictureBox2.Visible = False
'PictureBox3.Visible = True
End Sub
Private Sub ComboBox1_SelectedIndexChanged_1(ByVal sender As System.Object, ByVal e
As System.EventArgs) Handles ComboBox1.SelectedIndexChanged
picB_big.Image = ImageList1.Images(ComboBox1.SelectedIndex)
'getting the image from the image list by its index and we get the image index
'by getting the selected item index fro the combo box.
'For more details about the image size and image bit depth properties of the
image list,
'please check the handout.
End Sub
End Class
Port Said International Schools – National Section
Revision Handout
Better education for future generations
Grade: 10
Simple Calculator:
Public Class Form1
Dim num1, num2, total As Integer
'the variables are public which means that we
can use them in any place in the code
Private Sub btn_factorial_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btn_factorial.Click
num1 = txt_num1.Text
total = 1
'initialize the total variable with 1 because we're multiplying numbers
' we can't initialize it to 0, because the result will always be zero
For index = 1 To num1 - 1
'don't forget the start value and the end value
total = num1 * total
num1 = num1 - 1
'num1 -= 1
'another way to decrease the value of num
'num-'another way to decrease the value of num
Next
' next keyword is required
lbl_result.Text = total
the text property
'displaaying the final result in the label by using
End Sub
Private Sub btn_add_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btn_add.Click
num1 = txt_num1.Text
num2 = txt_num2.Text
total = num1 + num2
lbl_result.Text = total
End Sub
Private Sub btn_sub_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btn_sub.Click
num1 = txt_num1.Text
num2 = txt_num2.Text
total = num1 - num2
lbl_result.Text = total
End Sub
Private Sub btn_multi_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btn_multi.Click
num1 = txt_num1.Text
num2 = txt_num2.Text
total = num1 * num2
lbl_result.Text = total
End Sub
Private Sub btn_divide_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btn_divide.Click
num1 = txt_num1.Text
num2 = txt_num2.Text
If num2 <> 0 Then
'if statement to make sure that we don't divide a
number by zero
total = num1 / num2
lbl_result.Text = total
Else
MsgBox("Can't divide by zero")
'message box to show a friendly error
message
txt_num2.Text = 1
End If
End Sub
End Class