I am new to vb.net and i'm needing help with this small calculator program and will appreciate whoever can help me out. I am able to write the program to do the calculations right but my instructor specifically wants me to use a single event handler to handle all the operations like +,-,* and even = signs. It would have been easier for me if this was java because that's what i'm used to but not vb. Below is my code so far, Only the addition works now and i need to include codes for the other calculations using the same even handler i.e operations_click. some functions are not working but they should not affect the overall performance of the program. Please ignore the EqualsButton_Click, i'm the one using that to test first, it should be included in the Operations_click method and not stand alone. Thanks guys




Public Class CalculatorForm
Private FirstNumberInput As Double = 0
Private LastNumberInput As Double = 0
Private OperationCheck As Boolean = False
Private Operation As String
Private Sub OneButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OneButton.Click
If ResultLabel.Text = "0" Then
ResultLabel.Text = "1"
Else
ResultLabel.Text = ResultLabel.Text & OneButton.Text 'Appends the number "1" to user entry
End If
End Sub

Private Sub TwoButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TwoButton.Click
If ResultLabel.Text = "0" Then
ResultLabel.Text = "2"
Else
ResultLabel.Text = ResultLabel.Text & TwoButton.Text 'Appends the number "2" to user entry
End If
End Sub

Private Sub ThreeButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ThreeButton.Click
If ResultLabel.Text = "0" Then
ResultLabel.Text = "3"
Else
ResultLabel.Text = ResultLabel.Text & ThreeButton.Text 'Appends the number "3" to user entry
End If
End Sub

Private Sub FourButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles FourButton.Click
If ResultLabel.Text = "0" Then
ResultLabel.Text = "4"
Else
ResultLabel.Text = ResultLabel.Text & FourButton.Text 'Appends the number "4" to user entry
End If
End Sub

Private Sub FiveButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles FiveButton.Click
If ResultLabel.Text = "0" Then
ResultLabel.Text = "5"
Else

ResultLabel.Text = ResultLabel.Text & FiveButton.Text 'Appends the number "5" to user entry
End If
End Sub

Private Sub SixButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SixButton.Click
If ResultLabel.Text = "0" Then
ResultLabel.Text = "6"
Else
ResultLabel.Text = ResultLabel.Text & SixButton.Text 'Appends the number "6" to user entry
End If
End Sub

Private Sub SevenButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SevenButton.Click
If ResultLabel.Text = "0" Then
ResultLabel.Text = "7"
Else
ResultLabel.Text = ResultLabel.Text & SevenButton.Text 'Appends the number "7" to user entry
End If
End Sub

Private Sub EightButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles EightButton.Click
If ResultLabel.Text = "0" Then
ResultLabel.Text = "8"
Else
ResultLabel.Text = ResultLabel.Text & EightButton.Text 'Appends the number "8" to user entry
End If
End Sub

Private Sub NineButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles NineButton.Click
If ResultLabel.Text = "0" Then
ResultLabel.Text = "9"
Else
ResultLabel.Text = ResultLabel.Text & NineButton.Text 'Appends the number "9" to user entry
End If
End Sub

Private Sub ZeroButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ZeroButton.Click
If ResultLabel.Text = "0" Then
ResultLabel.Text = "0"
Else
ResultLabel.Text = ResultLabel.Text & ZeroButton.Text 'Appends the number "0" to user entry
End If
End Sub

Private Sub DecimalButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles DecimalButton.Click
ResultLabel.Text = DecimalButton.Text & "" 'clears the screen
End Sub

Private Sub Operations_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles PlusButton.Click, MinusButton.Click, MultiplyButton.Click, DivideButton.Click

FirstNumberInput = ResultLabel.Text
ResultLabel.Text = "0"

Operation = "+"
End Sub
Private Sub BackSpaceButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BackSpaceButton.Click, ClearEntryButton.Click, AbortButton.Click
ResultLabel.Text = "0"
End Sub

Private Sub ResultLabel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ResultLabel.Click
ResultLabel.Text = 0
End Sub

Private Sub EqualsButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles EqualsButton.Click
Dim Result As Double

LastNumberInput = ResultLabel.Text
If Operation = "+" Then
Result = FirstNumberInput + LastNumberInput
ElseIf Operation = "-" Then
Result = FirstNumberInput - LastNumberInput
End If
FirstNumberInput = Result
ResultLabel.Text = Result
End Sub

End Class

When you say single event handler, I don't know if there is a standard to map all events in VB.NET application to one handler, I have never come across such. Unless you mean map to a single function or sub.

I meant a single even handler to handle the click events for all the operations +,-,*/ and /. Thanks for the response

If you click any of the arithmetic signs is this sub executed?

Private Sub Operations_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles PlusButton.Click, MinusButton.Click, MultiplyButton.Click, DivideButton.Click

        FirstNumberInput = ResultLabel.Text
        ResultLabel.Text = "0"

        Operation = "+"
    End Sub

this will work

Private Sub Operations_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles PlusButton.Click, MinusButton.Click, MultiplyButton.Click, DivideButton.Click

FirstNumberInput = resultlabel.Text
resultlabel.Text = "0"
If PlusButton.Focused Then
Operation = 1
Else
If MinusButton.Focused Then
Operation = 2
Else
If DivideButton.Focused Then
Operation = 3
Else
If MultiplyButton.Focused Then
Operation = 4
End If
End If
End If
End If

End Sub

Private Sub equal_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles equal.Click
Dim Result As Double

LastNumberInput = resultlabel.Text
If Operation = 1 Then
Result = FirstNumberInput + LastNumberInput
Else
If Operation = 2 Then
Result = FirstNumberInput - LastNumberInput
End If
If Operation = 3 Then
Result = FirstNumberInput / LastNumberInput
Else
If Operation = 4 Then
Result = FirstNumberInput * LastNumberInput
End If
End If
End If
FirstNumberInput = Result
resultlabel.Text = Result
End Sub

Hi guys,
Thanks for your help but fortunately for me, i was able to figure how to make everything work which is why I have not been able to check for any update on here. dellnet and T.Red i'm grateful to you both for willing to help.