1. Design the form.
2. Create a command Button
named as a Command1 and copy that and paste it 10 times. This will create a
control array.
3. Create a cmdoperator
control array using another Command Button named as Command2.
4. Place Command Button named
as Command3 and set its caption to ‘clear’.
5. Place Command Button named
as Command4 and set its caption to ‘=’.
6. place a Textbox for the
Display.
DESIGN VIEW:
CODING:
Private lastoperator As
String
Private firstpart As String
Private Sub Form_Load()
TxtResult.Enabled = False
Me.KeyPreview = True
End Sub
Private Sub
Form_KeyDown(KeyCode As Integer, Shift As Integer)
'number in main keyboard
If (KeyCode >= 48 And
KeyCode <= 57) Then
addDigits (Chr(KeyCode))
End If
'numbers in numpad
If (KeyCode >= 96 And
KeyCode <= 105) Then
addDigits (Chr(KeyCode - 48))
End If
'if backspace
If (KeyCode = 8) Then
If (TxtResult.Text <>
"") Then
TxtResult.Text =
Left(TxtResult.Text, Len(TxtResult.Text) - 1)
End If
End If
'for various operators
If (KeyCode = 111) Then
registerOperator ("/")
If (KeyCode = 106) Then
registerOperator ("*")
If (KeyCode = 109) Then
registerOperator ("-")
If (KeyCode = 107) Then registerOperator
("+")
End Sub
Private Sub
cmdoperator_Click(Index As Integer)
registerOperator
(cmdoperator(Index).Caption)
End Sub
Private Sub cmdclear_Click()
firstpart = ""
lastoperator = ""
TxtResult.Text = ""
End Sub
Private Sub Cmdequals_Click()
Select Case lastoperator
Case Is = "+"
TxtResult.Text = firstpart -
TxtResult.Text + TxtResult.Text + TxtResult.Text
Case Is = "-"
TxtResult.Text = firstpart -
TxtResult.Text
Case Is = "/"
TxtResult.Text = firstpart /
TxtResult.Text
Case Is = "*"
TxtResult.Text = firstpart *
TxtResult.Text
End Select
firstpart = ""
lastoperator = ""
End Sub
Private Sub
Command1_Click(Index As Integer)
addDigits
(Command1(Index).Caption)
End Sub
Private Sub addDigits(Digit
As String)
TxtResult.Text =
TxtResult.Text & Digit
End Sub
Private Sub
registerOperator(Operatortext As String)
lastoperator = Operatortext
firstpart = TxtResult.Text
TxtResult.Text = ""
End Sub
OUTPUT:
