Question

我在VB.Net中制作一个简单的计算器

我正在扩展代码，因为我想要这样做，如果你做这样的操作

input(8) input(+) input(2) input(=) result(10)

但是如果我像分频按钮和其他数字一样按下我想这样：

 previousResult(10) input(/) input(5) input(=) newResult(2)

此外，如果我不经常按下相同的操作员继续进行计算它还应该给出正确的值

input(8) input(+) input(2) input(/) input(2) input(+) input(5) input(=) result(10)

无论计算新操作多少次，它都应该继续运行。无论我点击什么算子（+， - ，/，*）

，它都应该继续运行

我已经制作了许多变量和功能，整个事情都很乱。我的第一个计算将适用于case +

但是在其他情况下+结果是错误的......这是我的代码：

Option Strict On
Option Infer Off
Option Explicit On


    Public Class SimpleCalculatorForm

    #Region "FormLoad"

    Private Sub SimpleCalculatorForm_Load(ByVal sender As System.Object, ByVal e As EventArgs) Handles MyBase.Load
        Dim decimalSeperator As Char = Convert.ToChar(Globalization.CultureInfo.CurrentCulture.NumberFormat.NumberDecimalSeparator)
        DecimalSeperatorButton.Text = decimalSeperator

        ResultTextbox.Text = "0"
    End Sub
#End Region

#Region "Methods"


    Private Sub RemoveMinusBeforeValue()
        For Each letter As String In ResultTextbox.Text
            Dim pos As Integer = pos + 1
            If letter = "-" Then
                ResultTextbox.Text = ResultTextbox.Text.Substring(pos, ResultTextbox.Text.Length - pos)
                Exit For
            End If
        Next
    End Sub

    Public Function ThereIsAnValue() As Boolean
        Dim x As Boolean
        For Each number As String In ResultTextbox.Text
            If number <> "0" Then
                x = True
                Exit For
            Else : x = False
            End If
        Next
        Return x
    End Function
    Public Function TextboxContainsDecimalSeparator() As Boolean
        Dim x As Boolean
        For Each letter As String In ResultTextbox.Text
            If letter = "," Then
                x = True
                Exit For
            Else : x = False
            End If
        Next
        Return x
    End Function
    Public Function TheValueIsPositive() As Boolean
        Dim x As Boolean
        For Each letter As String In ResultTextbox.Text
            If letter = "-" Then
                x = False
                Exit For
            Else : x = True
            End If
        Next

        Return x
    End Function

    Public Sub ContainsZero(number As String)
        If ResultTextbox.Text = "0" OrElse ResultTextbox.Text = "-0" Then
            ResultTextbox.Text = number
        ElseIf ResultTextbox.Text = "0.0" AndAlso number = "0" Then
            ResultTextbox.Text = number

        Else : ResultTextbox.Text &= number
        End If
    End Sub

#End Region


#Region "NumericButtons"

    Private Sub Numeric_Buttons_Click(sender As Object, e As EventArgs) Handles ZeroButton.Click, OneButton.Click, TwoButton.Click, ThreeButton.Click, _
                                                                            FourButton.Click, FiveButton.Click, SixButton.Click, SevenButton.Click, _
                                                                                EightButton.Click, NineButton.Click

        Dim x As Button = CType(sender, Button)
        Dim button As String = x.Text
        ContainsZero(button)

        If _Calculatevalue1 = Nothing Then
            _Calculatevalue1 &= button
        Else
            _Calculatevalue2 &= button
        End If


    End Sub



    Private Sub DecimalSeperatorButton_Click(sender As Object, e As EventArgs) Handles DecimalSeperatorButton.Click
        Dim x As Button = CType(sender, Button)
        Dim button As String = x.Text

        If TextboxContainsDecimalSeparator() = True Then
            MessageBox.Show("You cannot enter 2 times the ',' sign")
        Else : ResultTextbox.Text &= button
        End If


    End Sub

#End Region


#Region "OperatorButtons"


    Private Sub ClearButton_Click(sender As Object, e As EventArgs) Handles ClearButton.Click

        If ResultTextbox.Text = "0" Then
            MessageBox.Show("The field is already empty")
        ElseIf ResultTextbox.Text <> "0" Then
            ResultTextbox.Text = "0"
            _Calculatevalue1 = Nothing
            _Calculatevalue2 = Nothing
            _Calculatevalue3 = Nothing



        End If


    End Sub

    Private Sub NegationButton_Click(sender As Object, e As EventArgs) Handles NegationButton.Click

        If TheValueIsPositive() Then
            ResultTextbox.Text = "-" & ResultTextbox.Text
            _Calculatevalue3 = ResultTextbox.Text
        Else : RemoveMinusBeforeValue()
            _Calculatevalue3 = ResultTextbox.Text

        End If
    End Sub

    Private _Calculatevalue1 As String
    Private _Calculatevalue2 As String
    Private _TheFinalResult As Decimal
    Private _CurrentOperator As String
    Private _Calculatevalue3 As String


    Private Sub Operators_Buttons_Click(sender As Object, e As EventArgs) Handles AdditionButton.Click, SubtractionButton.Click, _
                                                                                MultiplicationButton.Click, DivisionButton.Click
        Dim x As Button = CType(sender, Button)
        Dim button As String = x.Text

        _CurrentOperator = button



        If _Calculatevalue1 = Nothing AndAlso ThereIsAnValue() = False Then
            MessageBox.Show("Give in a value before u use an operator")


            ResultTextbox.Text = "0"

        Else
            If ThereIsAnValue() Then

                If _Calculatevalue3 = Nothing Then
                    Select Case button

                        Case "+"
                            _Calculatevalue3 = Convert.ToString(Convert.ToDecimal(_Calculatevalue1) + Convert.ToDecimal(_Calculatevalue2))
                            ResultTextbox.Text = "0"


                    End Select

                Else
                    Select Case button

                        Case "+"
                            _Calculatevalue3 = Convert.ToString(Convert.ToDecimal(_Calculatevalue3) + Convert.ToDecimal(_TheFinalResult))
                            ResultTextbox.Text = "0"

                    End Select
                End If
            End If
        End If
    End Sub

    Private Sub EqualsButton_Click(sender As Object, e As EventArgs) Handles EqualsButton.Click
        Select Case _CurrentOperator

            Case "+"
                _TheFinalResult = Convert.ToDecimal(_Calculatevalue1) + Convert.ToDecimal(_Calculatevalue2)
                ResultTextbox.Text = _TheFinalResult.ToString
        End Select
        _Calculatevalue1 = Nothing

    End Sub
#End Region
End Class

不要犹豫，删除代码或更改内容。我可以说我写了很多。

Answer 1

我会保持一个总计。如果下一个输入是数学运算（例如，+，/，*， - ），则使用运行总计作为第一个操作数。但是，如果它是一个数字，则清除运行总计并开始新的计算。

Answer 2

许多代码需要通过，但您可能需要一个模块/表单/类级别变量，它在各种过程之外仍然存在：

Public Class SimpleCalculatorForm

 Friend CurrentResult As Integer        ' ??? doesnt look like you care
                                        ' much about datatpes
#Region "FormLoad"

使用currentresult存储......好吧，当前结果只有当用户按下'C'或等号两次或类似的东西时才会清除。这样，当前结果将在calc程序之外持续存在（即scope）。

Answer 3

如果您不关心操作员的优先级，那么“=”按钮除了显示最终结果外不应该做很多事情。计算每个运算符的最终结果。

最终结果= 0

如果按“+”，则将下一个数字添加到最终结果中如果按“ - ”，则将下一个数字减去最终结果
如果按“/”，则将下一个数字除以最终结果
如果按“*”，则将下一个数字乘以最终结果
如果按“=”，则显示最终结果

最终结果= 0
输入（8）
将8添加到最终结果中输入（+）输入（2）
将2添加到最终结果中输入（=）
显示最终结果

输入（/）输入（5）
将5除以最终结果
输入（=）
显示最终结果

继续计算计算器

3 个答案: