namespace calculator
{
    public partial class Form1 : Form
    {
        public static string op;
        public static double n1;
        public Form1()
        {
            InitializeComponent();
        }

        private void buttonH9_Click(object sender, EventArgs e)
        {
            textBox1.Text += "1";
        }

        private void buttonH10_Click(object sender, EventArgs e)
        {
            textBox1.Text += "2";
        }

        private void buttonH11_Click(object sender, EventArgs e)
        {
            textBox1.Text += "3";
        }

        private void buttonH5_Click(object sender, EventArgs e)
        {
            textBox1.Text += "4";
        }

        private void buttonH6_Click(object sender, EventArgs e)
        {
            textBox1.Text += "5";
        }

        private void buttonH7_Click(object sender, EventArgs e)
        {
            textBox1.Text += "6";

        }

        private void buttonH1_Click(object sender, EventArgs e)
        {
            textBox1.Text += "7";
        }

        private void buttonH2_Click(object sender, EventArgs e)
        {
            textBox1.Text += "8";
        }

        private void buttonH3_Click(object sender, EventArgs e)
        {
            textBox1.Text += "9";
        }

        private void buttonH13_Click(object sender, EventArgs e)
        {
            textBox1.Text += "0";
        }

        private void buttonH17_Click(object sender, EventArgs e)
        {
            textBox1.Text = "";
        }

        private void buttonH15_Click(object sender, EventArgs e)
        {
            try
            {
                switch (op)
                {
                    case "/":
                        textBox1.Text = Convert.ToString(n1 / Convert.ToDouble(textBox1.Text));
                        break;
                    case "*":
                        textBox1.Text = Convert.ToString(n1 * Convert.ToDouble(textBox1.Text));
                        break;
                    case "+":
                        textBox1.Text = Convert.ToString(n1 + Convert.ToDouble(textBox1.Text));
                        break;
                    case "-":
                        textBox1.Text = Convert.ToString(n1 - Convert.ToDouble(textBox1.Text));
                        break;
                }

            }
            catch
            {

            }
        }

        private void buttonH4_Click(object sender, EventArgs e)
        {
            try
            {
                op = "/";
                n1 = Convert.ToDouble(textBox1.Text);
                textBox1.Text = "";
            }
            catch
            {

            }
        }

        private void buttonH8_Click(object sender, EventArgs e)
        {
            try
            {
                op = "*";
                n1 = Convert.ToDouble(textBox1.Text);
                textBox1.Text = "";
            }
            catch { }
        }

        private void buttonH12_Click(object sender, EventArgs e)
        {
            try
            {
                op = "-";
                n1 = Convert.ToDouble(textBox1.Text);
                textBox1.Text = "";
            }
            catch
            {
            }
        }

        private void buttonH16_Click(object sender, EventArgs e)
        {
            try
            {
                op = "+";
                n1 = Convert.ToDouble(textBox1.Text);
                textBox1.Text = "";
            }
            catch
            {
 
            }
        }

        private void buttonH14_Click(object sender, EventArgs e)
        {
            textBox1.Text += ".";
        }
    }