กหฟ

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace simplecalculater2018
{
    public partial class Form1 : Form
    {
        String number;
        Double number1, number2, result;
        int count,ct=0;
        public Form1()
        {
            InitializeComponent();
        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {

        }

        private void button1_Click(object sender, EventArgs e)
        {
            number = number + "1";
            txtdisplay.Text = number;
        }

        private void button2_Click(object sender, EventArgs e)
        {
            number = number + "2";
            txtdisplay.Text = number;
        }

        private void button3_Click(object sender, EventArgs e)
        {
            number = number + "3";
            txtdisplay.Text = number;
        }

        private void button4_Click(object sender, EventArgs e)
        {
            number = number + "4";
            txtdisplay.Text = number;
        }

        private void button5_Click(object sender, EventArgs e)
        {
            number = number + "5";
            txtdisplay.Text = number;
        }

        private void button6_Click(object sender, EventArgs e)
        {
            number = number + "6";
            txtdisplay.Text = number;
        }

        private void button7_Click(object sender, EventArgs e)
        {
            number = number + "7";
            txtdisplay.Text = number;
        }

        private void button8_Click(object sender, EventArgs e)
        {
            number = number + "8";
            txtdisplay.Text = number;
        }

        private void button9_Click(object sender, EventArgs e)
        {
            number = number + "9";
            txtdisplay.Text = number;
        }

        private void button0_Click(object sender, EventArgs e)
        {
            number = number + "0";
            txtdisplay.Text = number;
        }

        private void ppoint_Click(object sender, EventArgs e)
        {
            number = number + ".";
            txtdisplay.Text = number;
        }

        private void buttonAC_Click(object sender, EventArgs e)
        {
            number = null;
            txtdisplay.Text = number;

        }

        private void button10_Click(object sender, EventArgs e)
        {
            number1 = Convert.ToDouble(number);
            number = null;
            count = 1;
            ct = 0;
        }

        private void mainug_Click(object sender, EventArgs e)
        {
            number1 = Convert.ToDouble(number);
            number = null;
            count = 2;
            ct = 0;
        }

        private void point_Click(object sender, EventArgs e)
        {
            number1 = Convert.ToDouble(number);
            number = null;
            count =3;
            ct = 0;
        }

        private void han_Click(object sender, EventArgs e)
        {
            number1 = Convert.ToDouble(number);
            number = null;
            count =4;
            ct = 0;
        }

        private void moldu_Click(object sender, EventArgs e)
        {
            number1 = Convert.ToDouble(number);
            number = null;
            count = 5;
            ct = 0;
        }

        private void equrl_Click(object sender, EventArgs e)
        {
            if(ct == 0)
            {
                number2 = Convert.ToDouble(number);
                ct = 8;
            }
            if (count==1)
            {
                result = number1 + number2;

            }
            else if (count==2)
            {
                result = number1 - number2;

            }
            else if (count==3)
            {
                result = number1 * number2;


            }
            else if (count==4)
            {
                result = number1 / number2;

            }else if(count == 5)
            {

            }
            number = Convert.ToString(result);
            txtdisplay.Text = number;
        }
    }
}