Calculate numbers with comma and decimal

Question

Hi everyone, i started understanding some calculation code but finding difficulty in some aspect. Quick Scenario: i have 3 textbox wherein if you type 1234567.5678 it will automatically display 1,234,567.57

HERE is the code from 1 of the 3 textboxes namely txtAmountCash which has the same code for the rest of the 2 textboxes. (i got this code from the internet)

    Private Sub txtAmountCash_KeyPress(sender As Object, e As System.Windows.Forms.KeyPressEventArgs) Handles txtAmountCash.KeyPress
        Dim txtval As String = txtAmountCash.Text
        Dim decval As Decimal
        If Not Char.IsDigit(e.KeyChar) Then e.Handled = True 'no non-numeric characters allowed
        If e.KeyChar = Chr(8) Then e.Handled = False 'allow backspace
        If Not txtval.Contains(".") And e.KeyChar = "," Then e.Handled = False 'allow commas ONLY if no decimal points present
        If e.KeyChar = "." And txtAmountCash.Text.IndexOf(".") = -1 Then e.Handled = False 'allow single decimal point
        If txtval.Length >= 28 Then
            MessageBox.Show("Maximum number of digits limited to 28")
            If e.KeyChar = Chr(8) Then e.Handled = False Else e.Handled = True
            txtAmountCash.Text = txtval.Substring(0, 28)     'allow backspace to work
            txtAmountCash.SelectionStart = txtAmountCash.TextLength   'cursor moved to end of text
        End If
        If e.KeyChar = Chr(13) Then
            Decimal.TryParse(txtval, decval)
            If txtval.Contains(".") Then
                txtval = decval.ToString("n")       'displays with 2 places after decimal point
            Else
                txtval = Format(decval, "###,###") 'no decimal point
            End If
            txtAmountCash.Text = txtval
        End If
    End Sub

    Private Sub txtAmountCash_LostFocus(sender As Object, e As System.EventArgs) Handles txtAmountCash.LostFocus
        Dim txtval As String = txtAmountCash.Text
        Dim decval As Decimal
        If Decimal.TryParse(txtval, decval) Then
            If txtval.Contains(".") Then
                txtval = decval.ToString("n")       'displays with 2 places after decimal point
            Else
                txtval = Format(decval, "###,###") 'no decimal point
            End If
        End If
        txtAmountCash.Text = txtval
    End Sub

If I input 1000000.567 to txtAmountCash, it automatically changes to 1,000,000.57

If I input 2500000.678 to txtAmountCheck, it automatically changes to 2,500,000.68

If I input 3000000.789 to txtAmountCredit, it automatically changes to 3,000,000.79

HERE'S MY QUESTION: how can i add these 3 textboxes?

It must show a result of 6,500,002.04

Answer 1

Convert the text in the textboxes to Decimal variables and add them.

Dim num1 as Decimal = CDec(TextBox1.Text)
Dim num2 as Decimal = CDec(TextBox2.Text)
Dim num3 as Decimal = CDec(TextBox3.Text)

Dim total As Decimal = num1 + num2 + num3
MessageBox.Show("Total is :" & total.ToString("N2"))

Answer 2

You should take a look at using Decimal.TryParse.  One of the overloads allows commas and decimal points.

Imports System.Globalization

Public Class Form1

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim value As String = "$1,097.63"
        Dim style As NumberStyles
        Dim culture As CultureInfo = CultureInfo.CurrentCulture
        Dim number As Decimal

        style = NumberStyles.Number Or NumberStyles.AllowCurrencySymbol

        If Decimal.TryParse(value, style, culture, number) Then
            Debug.WriteLine("Converted '{0}' to {1}.", value, number)
        Else
            Debug.WriteLine("Unable to convert '{0}'.", value)
        End If
    End Sub
End Class

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'Those who use Application.DoEvents() have no idea what it does and those who know what it does never use it.'  JohnWein

Multics

My Serial Port Answer

Answer 3

You should convert the text in the TextBoxes to decimals before you do the calculation:

        Dim sum As Decimal = Decimal.Parse(txtAmountCash.Text, System.Globalization.CultureInfo.InvariantCulture) + Decimal.Parse(txtAmountCheck.Text, System.Globalization.CultureInfo.InvariantCulture) + Decimal.Parse(txtAmountCredit.Text, System.Globalization.CultureInfo.InvariantCulture)

Of course this assumes that the TextBoxes contain some text that can actually be converted into decimals like for example "1,000,000.57"

Please remember to mark helpful posts as answer and/or helpful.

Answer 4

thanks, i tried all of your suggestions and it worked. Thanks for your relies, appreciate much!