With A Percentage Sign After Numeric Numbers is preventing me to calculate sums

Question

Percentage Sign After Numeric Numbers I have in Different Labels,

Example of Label values, Label1 ( 0%) , Label2 (13.25%), Label3 (3.25%)

When I try to get a value from one of the above Labels, And times One of the above Labels with

Another Label ( LbTaxRate ) Then I want to put a value into a textbox. But Nothing seems to happen or I get thrown an Error.

My Question is How do I remove the Percent sign before doing the sum. Code I have at the Moment is below... plus image of my table of Labels

 If LbPayPeriod.Text = "Weekly" AndAlso LbTaxLetter.Text = "L" And GetDec(TxtAmountEarned.Text >= GetDec(TxtHeader2WFrom.Text) AndAlso

          GetDec(TxtAmountEarned.Text <= GetDec(TxtHeader2WTo.Text))) Then



            Dim Sum3 As Decimal = GetPercent(LbB2.Text) * GetDec(TxtTaxableIncome.Text) / 100

            Dim Sum4 As Decimal = GetPercent(LbL2.Text)



            TxtN_I_Deductions.Text = FormatCurrency(Sum3)



        End If



    End Sub


    Function GetPercent(s As String) As Decimal

        If s.EndsWith("%") Then

            s = s.Substring(1, s.Length - 1)

        End If

        Dim v As Decimal = 0D

        If Decimal.TryParse(s, v) Then Return v

        Return 0D

    End Function

Answer 1

Hi

Here is one way to do it.

Option Strict On
Option Explicit On
Public Class Form1
  Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

    Dim s As String = "22.55%"

    ' here, a valid Decimal numeric value
    ' is available (0 if string was not
    ' a valid Decimal)
    Dim dec As Decimal = GetPercent(s)

    Stop

  End Sub
  Function GetPercent(s As String) As Decimal
    Dim ss As String = s.Replace("%"c, String.Empty)
    Dim v As Decimal = 0.0D
    If Decimal.TryParse(ss, v) Then
      Return v
    End If
    ' if the string can not be converted to
    ' a valid Decimal then it will return 0
    Return 0.0D
  End Function
End Class

Answer 2

Hi

Here is a very small stand alone example where textboxes contain either a trailing % or currency symbol. The example caters for numeric conversion of either to use in calculating a result. The advantage of something like this is that any number of textboxes/labels in appropriate groups can be looped through with minimal code.

The example uses local currency symbol and a trailing % (NOTE: not a % function which multiplies number by 100).

If you choose to try this out, start a new test project and copy/paste the code (the Form is blank)

Option Strict On
Option Explicit On
Imports System.Globalization
Public Class Form1
  Dim WithEvents tb1, tb2 As New TextBox
  Dim lab1 As New Label
  Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    ' 2 textboxes and 1 label for demo
    With tb1
      .Text = 22.55.ToString("#.##\%")
      ' OR    .Text = "22.55%"
      .Location = New Point(10, 20)
      .TextAlign = HorizontalAlignment.Right
      .AutoSize = True
      .Font = New Font(.Font.FontFamily, 16)
    End With
    With tb2
      .Text = 123.6.ToString("C2")
      ' OR    .Text = "£123.6" local currency symbol
      .Location = New Point(140, 20)
      .TextAlign = HorizontalAlignment.Right
      .AutoSize = True
      .Font = New Font(.Font.FontFamily, 16)
    End With
    With lab1
      .Location = New Point(280, 20)
      .TextAlign = ContentAlignment.MiddleRight
      .AutoSize = False
      .BorderStyle = BorderStyle.FixedSingle
      .Size = New Size(120, 30)
      .Font = New Font(.Font.FontFamily, 16)
    End With
    Controls.AddRange({tb1, tb2, lab1})
    Calc()
  End Sub
  Private Sub tb_Validated(sender As Object, e As EventArgs) Handles tb1.Validated, tb2.Validated
    Calc()
  End Sub
  Sub Calc()
    tb1.Text = GetDec(tb1.Text).ToString("#.##\%")
    lab1.Text = (GetDec(tb1.Text) * GetDec(tb2.Text) / 100).ToString("C2")

    tb2.Text = GetDec(tb2.Text).ToString("C2")
    lab1.Text = (GetDec(tb1.Text) * GetDec(tb2.Text) / 100).ToString("C2")
  End Sub
  Function GetDec(s As String) As Decimal
    Dim ss As String = s.Replace("%"c, String.Empty)
    Dim v As Decimal = 0.0D
    If Decimal.TryParse(ss,
                    NumberStyles.Any, CultureInfo.CurrentCulture, v) Then
      Return v
    End If
    Return 0.0D
  End Function
End Class