Remove all character except numbers and decimals?

[DerekM]

I want to know if there is an easy and short way to remove all characters except for numbers and decimals from a string. Either that or have a textbox that will only except numbers and decimals, but not a masked textbox.

[Pradeep1210]

Here is one way using LINQ.

Dim nums = From c In TextBox1.Text _
    Where Char.IsDigit(c) OrElse c = "." _
    Select num = c.ToString
TextBox1.Text = Join(nums.ToArray, "")

You may put this in the TextChanged event, with whatever customization you need, if you do not want this textbox to accept anything else.

[Empyreal]

Assuming you only want valid decimals, this would be a better approach:

Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
    If sender.Text <> String.Empty Then
        Dim TypedNumber As String = sender.Text
        Dim NumberRegex As String = "^[0-9]+\.?[0-9]*$"
        If Not System.Text.RegularExpressions.Regex.Match(TypedNumber, NumberRegex).Success Then
            sender.Text = sender.Text.Remove(sender.Text.Length - 1, 1)
            sender.SelectionStart = sender.Text.Length
        End If
    End If
End Sub

Edit: This would require decimals less than 1 to be typed as "0.5" instead of ".5". If that's a problem just change NumberRegex to "^[0-9]*\.?[0-9]*$"