Best way to limit textbox decimal input in c#

Question

How can I make a textbox in which can be only typed a number like 12.00 or 1231231.00 or 123123

I\'ve done this in a very long way and I\'m looking for the best and

Answer 1

    private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
    {
        if (!Char.IsNumber(e.KeyChar))
        {
            e.Handled = !(((TextBox)sender).SelectionStart != 0 && (e.KeyChar.ToString() == Application.CurrentCulture.NumberFormat.NumberDecimalSeparator && ((TextBox)sender).Text.IndexOf(Application.CurrentCulture.NumberFormat.NumberDecimalSeparator) == -1));
        }
    }

And you should check onLeave for Length == 0 I think...