namespace Calculadora_2._0
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void label1_Click(object sender, EventArgs e)
        {

        }

        private void button2_Click(object sender, EventArgs e)
        {

        }

        private void button4_Click(object sender, EventArgs e)
        {

        }

        private void button5_Click(object sender, EventArgs e)
        {

        }

        private void label3_Click(object sender, EventArgs e)
        {

        }

        private void label4_Click(object sender, EventArgs e)
        {

        }

        private void button1_Click(object sender, EventArgs e)
        {
            int num1, num2, resultado;

            num1 = Convert.ToInt16(textBox1.Text);
            num2 = Convert.ToInt16(textBox2.Text);

            resultado = num1 + num2;

            if (textBox1.Text == null)
            {
                throw new System.ArgumentException("Parameter cannot be null", "original");
            }

            if (textBox2.Text == null)
            {
                throw new System.ArgumentException("Parameter cannot be null", "original");
            }

            if (textBox1.Text == null) &&
            {
                throw new System.ArgumentException("Parameter cannot be null", "original");
            }

            label4.Text = Convert.ToString(resultado);
        }
    }
}