Question

我正在VB.NET Windows应用程序中创建一个计算器。所有运算符（加法和减法）都可以正常工作，但是，当我尝试使用除法或乘法进行计算时，第39行会抛出System.Data.SyntaxErrorException。这是引发异常的行：

Dim result = New DataTable().Compute(equation, Nothing)

是否有人知道为什么会发生这种情况？这是其余的代码：

Public Class Form1
    Private Sub ButtonClickMethod(sender As Object, e As EventArgs)           Handles num0.Click, num1.Click, num2.Click, num3.Click, num4.Click, num5.Click, num6.Click, num7.Click, num8.Click, num9.Click, opdivision.Click, opmultiply.Click, opdecimal.Click, opclear.Click, opminus.Click, opadd.Click, opequal.Click
        Dim button As Button = CType(sender, Button)
        If button.Name = "num1" Then
            TextBox1.Text = TextBox1.Text + "1"
        End If
        If button.Name = "num2" Then
            TextBox1.Text = TextBox1.Text + "2"
        End If
        If button.Name = "num3" Then
            TextBox1.Text = TextBox1.Text + "3"
        End If
        If button.Name = "num4" Then
            TextBox1.Text = TextBox1.Text + "4"
        End If
        If button.Name = "num5" Then
            TextBox1.Text = TextBox1.Text + "5"
        End If
        If button.Name = "num6" Then
            TextBox1.Text = TextBox1.Text + "6"
        End If
        If button.Name = "num7" Then
            TextBox1.Text = TextBox1.Text + "7"
        End If
        If button.Name = "num8" Then
            TextBox1.Text = TextBox1.Text + "8"
        End If
        If button.Name = "num9" Then
            TextBox1.Text = TextBox1.Text + "9"
        End If
        If button.Name = "num0" Then
            TextBox1.Text = TextBox1.Text + "0"
        End If
        If button.Name = "opdecimal" Then
            TextBox1.Text = TextBox1.Text + "."
        End If
        If button.Name = "opequal" Then
            Dim equation As String = TextBox1.Text
            Dim result = New DataTable().Compute(equation, Nothing)
            boxresult.Text = result
        End If
        If button.Name = "opminus" Then
            TextBox1.Text = TextBox1.Text + "-"
            boxoperator.Text = boxoperator.Text + "-"
        End If
        If button.Name = "opmultiply" Then
            TextBox1.Text = TextBox1.Text + "x"
            boxoperator.Text = boxoperator.Text + "x"
        End If
        If button.Name = "opdivision" Then
            TextBox1.Text = TextBox1.Text + "÷"
            boxoperator.Text = boxoperator.Text + "÷"
        End If
        If button.Name = "opadd" Then
            TextBox1.Text = TextBox1.Text + "+"
            boxoperator.Text = boxoperator.Text + "+"
        End If
        If button.Name = "opclear" Then
            TextBox1.Clear()
        End If
    End Sub

    Private Sub opbackspace_Click(sender As Object, e As EventArgs) Handles opbackspace.Click
        TextBox1.Text = TextBox1.Text.Remove(TextBox1.Text.Count - 1)
    End Sub
End Class

Answer 1

您必须使用不同的字符进行乘法和除法：

If button.Name = "opmultiply" Then
    TextBox1.Text = TextBox1.Text + "*"
    boxoperator.Text = boxoperator.Text + "x"
End If
If button.Name = "opdivision" Then
    TextBox1.Text = TextBox1.Text + "/"
    boxoperator.Text = boxoperator.Text + "÷"
End If

为什么我的计算器不计算除法或乘法？

1 个答案: