VINIL.APP/proba/Form/BuyTools.cs

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;
using System.Data.SqlClient;

namespace proba
{
    public partial class BuyTools : Form
    {
        bool discount = false;
        public int razmer = 0;
        public static string[] buy = new string[1];
        string id_product;
        DataBase dataBase = new DataBase();
        public BuyTools(string id_product, string product, string description, string price, string year_publishing, string country, string edition, string genre, string performer, string supplier)
        {
            InitializeComponent();
            text_name.Text = product;
            text_description.Text = description;
            text_price.Text = Convert.ToString(Math.Round(Convert.ToDouble(price), 2));
            text_output.Text = text_price.Text;
            textBox_year_publishing.Text = year_publishing;
            text_country.Text = country;
            text_edition.Text = edition;
            text_genre.Text = genre;
            text_performer.Text = performer;
            text_id_suplier.Text = supplier;
            this.id_product = id_product;
        }
        private void button_back_Click(object sender, EventArgs e)
        {
            this.Hide();
            Sales sales = new Sales();
            sales.ShowDialog();
        }
        private void text_input_TextChanged(object sender, EventArgs e)
        {
            if(text_input.Text == "")
            {
                text_input.Text = "0";
            }
            text_output.Text = Convert.ToString(GetSurrender(Convert.ToDouble(text_input.Text), Convert.ToDouble(text_price.Text)));
            text_output.Text = Convert.ToString(Math.Round(Convert.ToDouble(text_output.Text), 2));
            if (Convert.ToDouble(text_input.Text) <= Convert.ToDouble(text_price.Text))
            {
                label_output1.Visible = true;
                label_output2.Visible = false;
            }
            else
            {
                label_output2.Visible = true;
                label_output1.Visible = false;
            }
        }
        private void button_buy_Click(object sender, EventArgs e)
        {
            dataBase.openConnection();
            string str = DateTime.Now.ToString("d MMMM yyyy");
            string str1;
            SqlCommand sqlCommand1 = new SqlCommand($"SELECT id_employee From Employee WHERE login = '{PosleVHODA.login}'", dataBase.GetConnection());
            str1 = sqlCommand1.ExecuteScalar().ToString();
            var addQuery = $"insert into Sales (id_product, date_sale, id_employee, summa) values ('{id_product}','{str}','{str1}', '{Convert.ToDouble(text_price.Text)}')";
            var command = new SqlCommand(addQuery, dataBase.GetConnection());
            command.ExecuteNonQuery();
            MessageBox.Show("Покупка совершена");
            Sales.countBuyProducts = GetCountBuyProducts(Sales.countBuyProducts);
            Sales.summaBuyProducts = GetSummaBuyProducts(Sales.summaBuyProducts, Convert.ToDouble(text_price.Text));
            buy[razmer] = text_name.Text;
            Array.Resize(ref buy, buy.Length + 1);
            razmer++;
            dataBase.closeConnection();
            this.Hide();
            Sales sales = new Sales();
            sales.ShowDialog();
        }
        public void global_FormClosed(object sender, EventArgs e)
        {
            Application.Exit();
        }
        private void text_input_KeyPress(object sender, KeyPressEventArgs e)
        {
            char number = e.KeyChar;
            if (!Char.IsDigit(number) && number != 8 && !(e.KeyChar == ',')) // цифры и клавиша BackSpace
            {
                e.Handled = true;
            }
        }
        public static int GetCountBuyProducts(int countBuyProducts)
        {
            countBuyProducts++;
            return countBuyProducts;
        }


        public static double GetSummaBuyProducts(double summaBuyProducts, double summa)
        {
            summaBuyProducts = summaBuyProducts + summa; 
            return summaBuyProducts;
        }
        public static double ShareCount(double summa, double percent) 
        {
            summa = summa - summa *(double)(percent/100);
            return summa;
        }
        public static double GetSurrender(double summaCustomer, double summaProduct) 
        {
            summaProduct = summaProduct - summaCustomer;
            return summaProduct;
        }
        private void button_discount_Click(object sender, EventArgs e)
        {
            if (text_discount.Text == "")
            {
                MessageBox.Show("Поле скидка не заполнено");
            }
            else if (text_discount.Text == "0")
            {
                MessageBox.Show("Скидка не может быть равна 0");
            }

            else if (Convert.ToDouble(text_discount.Text) > 100)
            {
                MessageBox.Show("Скидка не может быть больше 100%");
            }
            else if (discount == true)
            {
                var confirmResult = MessageBox.Show("Вы точно хотите применить скидку?\nСкидка будет применена к уже уценённому товару", "Подтвердите применение скидки!", MessageBoxButtons.YesNo);
                if (confirmResult == DialogResult.Yes)
                {
                    text_price.Text = Convert.ToString(ShareCount(Convert.ToDouble(text_price.Text), Convert.ToDouble(text_discount.Text)));
                    text_price.Text = Convert.ToString(Math.Round(Convert.ToDouble(text_price.Text), 2));
                    showDiscount.Visible = true;
                    showDiscount.Text = showDiscount.Text + "+" + text_discount.Text + "%";
                    text_discount.Text = "";
                }
            }
            else
            {
                text_price.Text = Convert.ToString(ShareCount(Convert.ToDouble(text_price.Text), Convert.ToDouble(text_discount.Text)));
                text_price.Text = Convert.ToString(Math.Round(Convert.ToDouble(text_price.Text), 2));
                showDiscount.Visible = true;
                showDiscount.Text = showDiscount.Text + text_discount.Text + "%";
                text_discount.Text = "";
                discount = true;
            }
            text_input_TextChanged(sender, e);
        }

        private void text_discount_KeyPress(object sender, KeyPressEventArgs e)
        {
            char number = e.KeyChar;
            if (!Char.IsDigit(number) && number != 8 && !(e.KeyChar == ',')) // цифры и клавиша BackSpace
            {
                e.Handled = true;
            }
        }
    }
}