Question

我有一个文本框，单击计算器上的相应按钮可显示数字和运算符，然后单击=按钮即可得到结果。

问题是，我试图让它在数字超过999.99时显示逗号并进行计算。对于一个带有逗号的数字，它可以很好地起作用，但对于其他没有逗号的数字，则不能（仅在最后输入时才有效）。

例如：

1,111 + 33333 (works in calculation)
1,111 + 22,222 (doesn't work)
33333 + 1,111 (doesn't work either)

这是我的一些代码：

Private Sub ButtonClickMethod(sender As Object, e As EventArgs) Handles Button0.Click, Button1.Click, Button2.Click, Button3.Click, PlusButton.Click, EqualButton.Click
Dim button As Button = CType(sender, Button)

    'numbers
    If button.Name = "Button0" Then
        TextBox.Text = TextBox.Text + "0"
    End If
    If button.Name = "Button1" Then
        Dim val1 As String
        val1 = TextBox.Text + "1"
        TextBox.Text = val1
        TextBox.Text = Convert.ToDecimal(val1).ToString("#,##")
    End If
    If button.Name = "Button2" Then
        Dim val2 As String
        val2 = TextBox.Text + "2"
        TextBox.Text = val2
        TextBox.Text = Convert.ToDecimal(val2).ToString("#,##")
    End If
    If button.Name = "Button3" Then
        TextBox.Text = TextBox.Text + "3"
    End If
    'operations
    If button.Name = "PlusButton" Then
        TextBox.Text = TextBox.Text + "+"
    End If
    'equal/result
    If button.Name = "EqualButton" Then
        Dim equation As String = TextBox.Text.Replace(",", String.Empty)
        Dim results = New DataTable().Compute(equation, Nothing)
        TextBox.Text = results
    End If
End Sub

Answer 1

问题是，在按下2019-01-01 13:00:01 2.0 2019-01-01 13:00:02 3.0 2019-01-01 13:00:03 3.0 2019-01-01 13:00:04 4.0 2019-01-01 13:00:05 1.0 2019-01-01 13:00:06 2.0操作符之后，您的文本框可能包含两个数字。如果要格式化它们，则需要将字符串分成第一个数字，运算符和第二个数字，然后分别格式化两个数字。 timestamps = [ '2019-01-01 13:00:00.060000', #0 '2019-01-01 13:00:00.140000', #0 '2019-01-01 13:00:00.731000', #0 '2019-01-01 13:00:01.135000', #1 '2019-01-01 13:00:01.344000', #1 '2019-01-01 13:00:02.174000', #2 '2019-01-01 13:00:02.213000', #2 '2019-01-01 13:00:02.363000', #2 '2019-01-01 13:00:02.951000', #2 '2019-01-01 13:00:03.393000', #3 '2019-01-01 13:00:03.454000', #3 '2019-01-01 13:00:04.444000', #4 '2019-01-01 13:00:05.123000', #5 '2019-01-01 13:00:05.456000', #5 ] df = pd.DataFrame([1, 2, 1, 2, 3, 2, 3, 2, 1, 4, 4, 4, 1 ,4] ,columns=['A'], index=pd.to_datetime(timestamps)和+可以包含类似val1的内容，并且不能用val2进行转换。

我还将逻辑提取到可重用的方法中，而不是一遍又一遍地针对不同的按钮进行重复。

该文本框应仅用于显示，而不能用作输入的存储。

"13.2+5"

我们仍然必须声明两个方法ToDecimal和Private _input As String Private Sub TypeDigit(ByVal key As Char) _input += key Display() End Sub Private Sub TypeOperator(ByVal key As Char) _input += " " & key & " " Display() End Sub Private Sub Execute(ByVal key As Char) Select Case key Case "="c _input = Calculate(_input) Case "C"c _input = "" Case Else End Select Display() End Sub。请注意，我们有3种输入法。他们每个人最后都叫Calculate。 Display将进行所有格式化并将结果放入文本框中。

点击事件处理程序：

Display

Display方法非常棘手，因为我们可能必须格式化不完整的数字。例如。以小数点开头或结尾的数字或带有尾随零的数字。我们必须确保在格式化过程中保留这些内容。我结束了

Private Sub buttonClear_Click(ByVal sender As Object, ByVal e As EventArgs)
    Execute("C"c)
End Sub

Private Sub buttonDecimalPoint_Click(ByVal sender As Object, ByVal e As EventArgs)
    TypeDigit("."c)
End Sub

Private Sub button0_Click(ByVal sender As Object, ByVal e As EventArgs)
    TypeDigit("0"c)
End Sub

...

Private Sub button9_Click(ByVal sender As Object, ByVal e As EventArgs)
    TypeDigit("9"c)
End Sub

Private Sub buttonEquals_Click(ByVal sender As Object, ByVal e As EventArgs)
    Execute("="c)
End Sub

Private Sub buttonPlus_Click(ByVal sender As Object, ByVal e As EventArgs)
    TypeOperator("+"c)
End Sub

' other operators here...

我没有实现Display方法。我把它留给你。您必须像将Private Sub Display() Dim parts As String() = _input.Split(New Char() {" "c}, StringSplitOptions.RemoveEmptyEntries) Dim display As String = "" Dim n As Decimal For Each part As String In parts If part = "." Then display += "0." ElseIf part.EndsWith(".") AndAlso Decimal.TryParse(part.Substring(0, part.Length - 1), n) Then display += n.ToString("#,##0") & "." ElseIf Decimal.TryParse(part, n) Then Dim decimalPoint As Integer = part.IndexOf("."c) If decimalPoint >= 0 Then Dim numDecimals As Integer = part.Length - decimalPoint - 1 display += n.ToString("#,##0." & New String("0"c, numDecimals)) Else display += n.ToString("#,##0") End If Else display += " " & part & " " End If Next textBoxDisplay.Text = display End Sub方法中那样将输入拆分为多个部分。

在计算器的单个文本框中显示大数的逗号

1 个答案: