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 Kalkulator
{

    public partial class Form1 : Form
    {

        private string Operation = "";
        private float firstNumber;
        private float secondNumber;
        public Form1()
        {
            InitializeComponent();
        }

        private void Label1_Click(object sender, EventArgs e)
        {

        }
        private void ButtonSUM_Click(object sender,EventArgs e)
        {
            firstNumber = float.Parse(TextBoxInput.Text);

            Operation = "+";


        }
        private void ButtonDIF_Click(object sender, EventArgs e)
        {
            firstNumber = float.Parse(TextBoxInput.Text);
            Operation = "-";
        }
        private void ButtonDIV_Click(object sender, EventArgs e)
        {
            firstNumber = float.Parse(TextBoxInput.Text);
            Operation = "/";
        }
        private void ButtonMUL_Click(object sender, EventArgs e)
        {
            firstNumber = float.Parse(TextBoxInput.Text);
            Operation = "*";
        }
        private void ButtonEQ_Click(object sender, EventArgs e)
        {

            secondNumber = float.Parse(textBoxInput2.Text);

            switch (Operation)
            {
                case "*":
                    Output.Text = (firstNumber * secondNumber).ToString();

                    break;
                case "-":
                    Output.Text = (firstNumber - secondNumber).ToString();
                    break;
                case "+":
                    Output.Text = (firstNumber + secondNumber).ToString();
                    break;
                case "/":
                    Output.Text = (firstNumber / secondNumber).ToString();
                    break;

            }
            Operation = "";
        }



        private void TextBoxInput_KeyPress(object sender, KeyPressEventArgs e)
        {
            char ch = e.KeyChar;

            if (ch == 46 && TextBoxInput.Text.IndexOf('.') != -1 )
            {
                e.Handled = true;
                return;
            }
            if (!Char.IsDigit(ch) && ch!= 8 && ch!=46)
            {
                e.Handled = true;
            }
        }