Multi-Function Calculator (Microsoft Clone)

[Vectris]

A couple of days ago I whipped up this calculator which I modeled after the Microsoft Standard Calculator. I made it with Visual Basic 2005 so it should be compatible with 2008.

I programmed it exactly like the Microsoft one so it remembers the last operation and when you just press "=" it will execute it again. It even includes the Memory functions. The only two differences are the exponent button instead of the % button and also how decimals are handled. In the Microsoft calculator, the decimal is always shown and you simply allow numbers to be added to the left of it by pressing the decimal button. In my calculator, the decimal is not shown until you press the decimal button (which I think is better).

Screenshot


Here's the code in case you can't open the project files.

' Project Name:         Calculator
' Programmed By:        Daniel Dara on 4/15/09

Option Explicit On
Option Strict On

Public Class MainForm
    Dim Num1 As Decimal
    Dim Num2 As Decimal
    Dim Memory As Decimal
    Dim Operation As String
    Dim isDecimal As Boolean
    Dim EraseNext As Boolean
    Dim doOperation As Boolean = True

    Private Sub any_numberButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles zeroButton.Click, twoButton.Click, threeButton.Click, sixButton.Click, sevenButton.Click, oneButton.Click, nineButton.Click, fourButton.Click, fiveButton.Click, eightButton.Click
        Dim btn As Button = TryCast(sender, Button)
        If displayLabel.Text = "0" Or EraseNext Then displayLabel.Text = String.Empty : EraseNext = False
        displayLabel.Text &= btn.Text
    End Sub

    Private Sub clearentryButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles clearentryButton.Click
        displayLabel.Text = "0"
        isDecimal = False
        EraseNext = False
    End Sub

    Private Sub clearButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles clearButton.Click
        Num1 = 0
        Num2 = 0
        clearentryButton.PerformClick()
    End Sub

    Private Sub backspaceButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles backspaceButton.Click
        Dim Disp As String = displayLabel.Text
        If Disp.Substring(Disp.Length - 1) = "." Then isDecimal = False
        If CDec(Disp) <> 0 Then displayLabel.Text = Disp.Remove(Disp.Length - 1)
        Disp = displayLabel.Text
        If Disp.Length = 0 Then displayLabel.Text = "0"
    End Sub

    Private Sub operationButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles plusButton.Click, minusButton.Click, divisionButton.Click, multiplicationButton.Click, exponentButton.Click
        If Operation <> String.Empty And doOperation Then equalsButton.PerformClick()
        Dim btn As Button = TryCast(sender, Button)
        Operation = btn.Text
        Num1 = CDec(displayLabel.Text)
        EraseNext = True
        doOperation = True
    End Sub

    Private Sub equalsButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles equalsButton.Click

        If doOperation Then Num2 = CDec(displayLabel.Text)
        Select Case Operation
            Case "+"
                displayLabel.Text = (Num1 + Num2).ToString
            Case "-"
                displayLabel.Text = (Num1 - Num2).ToString
            Case "/"
                displayLabel.Text = (Num1 / Num2).ToString
            Case "*"
                displayLabel.Text = (Num1 * Num2).ToString
            Case "^"
                displayLabel.Text = (Num1 ^ Num2).ToString
            Case "sqrt"
                rootButton.PerformClick()
            Case "1/x"
                reciprocalButton.PerformClick()
            Case "+/-"
                signButton.PerformClick()
        End Select

        Num1 = CDec(displayLabel.Text)
        EraseNext = True
        doOperation = False
    End Sub

    Private Sub signButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles signButton.Click
        Dim Disp As String = displayLabel.Text
        If CDec(Disp) <> 0 Then Operation = "+/-" : If Disp.StartsWith("-") Then displayLabel.Text = Disp.Remove(0, 1) Else displayLabel.Text = "-" & Disp
    End Sub

    Private Sub decimalButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles decimalButton.Click
        If isDecimal = False Then isDecimal = True : displayLabel.Text &= "."
    End Sub

    Private Sub rootButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles rootButton.Click
        Num2 = CDec(displayLabel.Text)
        If Num2 <> 0 Then displayLabel.Text = Math.Sqrt(Num2).ToString : Operation = "sqrt"
    End Sub

    Private Sub reciprocalButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles reciprocalButton.Click
        Num2 = CDec(displayLabel.Text)
        If Num2 <> 0 Then displayLabel.Text = (1 / Num2).ToString : Operation = "1/x"
    End Sub

    Private Sub memorystoreButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles memorystoreButton.Click
        Memory = CDec(displayLabel.Text)
        If Memory <> 0 Then memoryLabel.Text = "M"
    End Sub

    Private Sub memoryrecallButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles memoryrecallButton.Click
        displayLabel.Text = Memory.ToString
        EraseNext = True
    End Sub

    Private Sub memoryclearButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles memoryclearButton.Click
        memoryLabel.Text = String.Empty
        Memory = 0
    End Sub

    Private Sub memoryaddButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles memoryaddButton.Click
        If CDec(displayLabel.Text) <> 0 Then
            Memory += CDec(displayLabel.Text)
            memoryLabel.Text = "M"
            Operation = String.Empty
        End If
    End Sub

    Private Sub anyButton_MouseUp(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles zeroButton.MouseUp, twoButton.MouseUp, threeButton.MouseUp, sixButton.MouseUp, signButton.MouseUp, sevenButton.MouseUp, rootButton.MouseUp, reciprocalButton.MouseUp, plusButton.MouseUp, oneButton.MouseUp, nineButton.MouseUp, multiplicationButton.MouseUp, minusButton.MouseUp, memorystoreButton.MouseUp, memoryrecallButton.MouseUp, memoryclearButton.MouseUp, memoryaddButton.MouseUp, fourButton.MouseUp, fiveButton.MouseUp, exponentButton.MouseUp, equalsButton.MouseUp, eightButton.MouseUp, divisionButton.MouseUp, decimalButton.MouseUp, clearentryButton.MouseUp, clearButton.MouseUp, backspaceButton.MouseUp
        ' Keeps any button from being highlighted, looks nicer.
        displayLabel.Focus()
    End Sub

End Class