Masking a textbox for Numbers only but wont accept BackSpace

Question

I have a textbox that I would like for only numbers. But if I hit the wrong number, I cant backspace to correct it. How can I allow backspaces to work. Thanks

    private void amount_PaidTextBox_KeyPress(object sender, KeyPressEventArgs e)
    {
        if (Char.IsNumber(e.KeyChar) != true)
        {
            e.Handled = true;
        }
    }

Answer 1

You could add a check to allow control characters as well:

if (Char.IsControl(e.KeyChar) != true && Char.IsNumber(e.KeyChar) != true)
{
    e.Handled = true;
}

Update: in response to person-b's comment on the code s/he suggests the following style (which is also how I would personally write this):

if (!Char.IsControl(e.KeyChar) && !Char.IsNumber(e.KeyChar))
{
    e.Handled = true;
}