Only allow two digits after decimal in textbox?

Question

I have a textbox where the user enters a number, but how can i make it so that if they type the \'.\' after it it only allows 2 decimal places?

private void          


        

Answer 1

To address Casperah's comment above you can change the conditional to handle control characters and allow editing if text is selected.

if (!char.IsControl(e.KeyChar) 
    && Regex.IsMatch(textBox1.Text, @"\.\d\d")
    && String.IsNullOrWhiteSpace(textBox1.SelectedText))
{
    e.Handled = true;
}