How can I format a value as money (ex. 123,456.50)

Question

I want to format the contents of my textbox while typing. I know that I can do this in LostFocus event, but I want it to be done while I am typing. Does anyone have any suggestions on how to implement this?

Answer 1

Rather than trying to rig this up yourself, consider using a control that's specifically designed to handle formatted input. Specifically, you need the MaskedTextBox control, which is an enhanced version of the existing textbox that allows you to set a "mask" used to distinguish between valid and invalid input. The user even gets visual feedback as they type.

You'll need to set the Mask property to tell the control how you want its contents to be formatted. All of the possible values are shown in the linked documentation. To display money, you would use something like: $999,999.00, which represents a currency value in the range of 0 to 999999. The neat part is that the currency, thousandth, and decimal characters are automatically replaced at run-time with their culture-specific equivalents, making it much easier to write international software.

Answer 2

Dim strCurrency As String = "" Dim acceptableKey As Boolean = False

Private Sub TextBox1_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles TextBox1.KeyDown If (e.KeyCode >= Keys.D0 And e.KeyCode <= Keys.D9) OrElse (e.KeyCode >= Keys.NumPad0 And e.KeyCode <= Keys.NumPad9) OrElse e.KeyCode = Keys.Back Then acceptableKey = True Else acceptableKey = False End If End Sub

Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
    ' Check for the flag being set in the KeyDown event.
    If acceptableKey = False Then
        ' Stop the character from being entered into the control since it is non-numerical.
        e.Handled = True
        Return
    Else
        If e.KeyChar = Convert.ToChar(Keys.Back) Then
            If strCurrency.Length > 0 Then
                strCurrency = strCurrency.Substring(0, strCurrency.Length - 1)
            End If
        Else
            strCurrency = strCurrency & e.KeyChar
        End If

        If strCurrency.Length = 0 Then
            TextBox1.Text = ""
        ElseIf strCurrency.Length = 1 Then
            TextBox1.Text = "0.0" & strCurrency
        ElseIf strCurrency.Length = 2 Then
            TextBox1.Text = "0." & strCurrency
        ElseIf strCurrency.Length > 2 Then
            TextBox1.Text = strCurrency.Substring(0, strCurrency.Length - 2) & "." & strCurrency.Substring(strCurrency.Length - 2)
        End If
        TextBox1.Select(TextBox1.Text.Length, 0)

    End If

e.Handled = True End Sub

@stynx

Answer 3

Private Sub TBItemValor_KeyPress(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TBItemValor.KeyPress
        If (Char.IsDigit(e.KeyChar) = False AndAlso Char.IsControl(e.KeyChar) = False AndAlso Char.IsPunctuation(e.KeyChar) = False) OrElse Not IsNumeric(Me.TBItemValor.Text & e.KeyChar) Then
            e.Handled = True
        End If
    End Sub