c#winform下textbox限定只能输入数字

        private void txtPort_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (e.KeyChar != '\b')//允许输入退格键
            {
                if ((e.KeyChar < '0') || (e.KeyChar > '9'))//允许输入0-9数字
                {
                    e.Handled = true;
                }
            }
        }