Textbox confussion

Textbox confussion

• Matheesha

  The problem with a mask is that you have to specify how many characters you want.  If you want to use a regular TextBox then I'd suggest a combination of the Enter event to remove formatting, the Validating event to validate the value and the Validated event to add formatting.  I strongly suggest NOT using the Leave event as it is not appropriate in this case:

  Private Sub TextBox1_Enter(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.Enter

      Dim myTextBox As TextBox = CType(sender, TextBox)

      Dim result As Decimal

      'Remove currency formatting.

      If Decimal.TryParse(myTextBox.Text, Globalization.NumberStyles.Currency, Nothing, result) Then

          myTextBox.Text = result.ToString()

      End If

  End Sub

  Private Sub TextBox1_Validating(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles TextBox1.Validating

      Dim myTextBox As TextBox = CType(sender, TextBox)

      'Make sure the user has eneterd a valid amount, allowing the currency symbol or not.

      If myTextBox.Text.Trim() <> String.Empty AndAlso _

        Not Decimal.TryParse(myTextBox.Text, Globalization.NumberStyles.Currency, Nothing, New Decimal) Then

          'Don't let the user leave the current control with an invalid value.

          myTextBox.HideSelection = False

          myTextBox.SelectAll()

          MessageBox.Show("Please enter a valid value.")

          myTextBox.HideSelection = True

          e.Cancel = True

      End If

  End Sub

  Private Sub TextBox1_Validated(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.Validated

      Dim myTextBox As TextBox = CType(sender, TextBox)

      Dim result As Decimal

      If myTextBox.Text.Trim() = String.Empty Then

          'Assume 0 for a empty string.

          result = 0D

      Else

          'Get the entered value, allowing the currency symbol or not.

          result = Decimal.Parse(myTextBox.Text, Globalization.NumberStyles.Currency)

      End If

      'Format the value as currency.

      myTextBox.Text = result.ToString("c"c)

  End Sub

   

  Note that this code allows the user to enter the currency symbol themselves or omit it.

   

  Edit: Note that you can also add additional validation to prevent the user entering illegal values in the first place, although it is not easy to do properly.  You can handle the KeyPress event to reject illegal characters but you need to consider where the currency symbol can go and the fact that you are allowed only one.  The same goes for the decimal point, and you have to worry about pasting illegal values from the clipboard.  There are third-party solutions available that do this for you.  The best I've seen is included in the free Windows Forms Components library from Quantum Software Solutions.  Unfortunately there is not a native .NET 2.0 version available yet, although I'm assured that it is on the way.

  
  

• xinz

  hi,

  you can try this

  Private Sub TextBox1_Enter(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.Enter

  Dim mytext As String = TextBox1.Text

  For Each chr As Char In mytext

  If Not Char.IsDigit(chr) Then

  'remove anyformat from the string including the .

  mytext = Replace(mytext, chr, "")

  'add the . again

  mytext = mytext.Insert(mytext.Length - 2, ".")

  End If

  Next

  TextBox1.Text = mytext

  End Sub

  Private Sub TextBox1_Leave(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.Leave

  Dim Mytext As Double = Double.Parse(TextBox1.Text)

  TextBox1.Text = Format(Mytext, "C2")

  End Sub

  hope this will help

  
  
  

• Talimar

  Have you tried the MaskedTextBox If you set the Mask to something like "$0,000.00", you will only be able to enter numbers, and it will be formatted accordingly.

  
  
  
• Textbox confussion