BookClubKMA/СУБД Книжный клуб/FormMain.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 СУБД_Книжный_клуб
{
    public partial class FormMain : Form
    {
        public FormMain()
        {
            InitializeComponent();
        }
       public SqlConnection Con = new SqlConnection(TxtCon);
       public static string TxtCon = @"Data Source=213.155.192.79,3002;Initial Catalog=BookClubKMA;Persist Security Info=True;User ID=u21kleschenkov;Password=vhk5";
        public class OrderItem
        {
            public string IdProduct, NameProduct;
            public double Cost, Discount;
            public int CountInStorage, Count, CountInOrder;
        }
        static List<OrderItem> LstOrder = new List<OrderItem>();

        /// <summary>
        /// Подччёт суммы заказа и суммы скидки
        /// </summary>
        /// <param name="Sum">Сумма заказа с учетом скидки</param>
        /// <param name="DiscountSum">Сумма скидки</param>
        public static void CalcOrder(ref double Sum, ref double DiscountSum)
        {
            Sum= 0;
            DiscountSum= 0;
            
            double CostItem = 0, DiscountItem = 0;
           
            for (int i = 0; i < LstOrder.Count; i++)
            {
                CostItem = LstOrder[i].Cost * LstOrder[i].CountInOrder;
                DiscountItem = CostItem * LstOrder[i].Discount / 100;
                DiscountSum += DiscountItem;
                Sum+= CostItem - DiscountItem;
            }
        }


        /// <summary>
        /// Заполнение списков товаров, имеющихся на складе
        /// </summary>

        void FillListProduct()
        {
            DgvProductList.Rows.Clear();
            Con.Open();
            string TxtQuery = @"SELECT Product.IdProduct, Product.Photo,
Product.NameProduct, Manufacturer.NameManufacturer, Product.Cost,
Product.Discount, Product.CountProduct, Product.Description
FROM Product INNER JOIN Manufacturer ON Product.IdManufacturer = 
Manufacturer.IdManufacturer";
            SqlCommand Query = new SqlCommand(TxtQuery, Con);
            SqlDataReader Res= Query.ExecuteReader();
            while (Res.Read())
            {
                string Info = $@"Товар: {Res["NameProduct"]}
Производитель: {Res["NameManufacturer"]}
Описание: {Res["Description"]}
Цена: {Res["Cost"]}
Скидка: {Res["Discount"]}
Кол-во на складе: {Res["CountProduct"]}";
                try
                {
                    DgvProductList.Rows.Add(Res["IdProduct"], Image.FromFile(Application.StartupPath + "\\Фото\\" + Res["Photo"]), Info, Res["NameProduct"], Res["Cost"], Res["Discount"], Res["CountProduct"]);
                }
                catch
                {
                    DgvProductList.Rows.Add(Res["IdProduct"], Image.FromFile(Application.StartupPath + "\\Фото\\blank.jpg" + Res["Photo"]), Info, Res["NameProduct"], Res["Cost"], Res["Discount"], Res["CountProduct"]);
                }
            }
            Con.Close();    
        }

        private void FormMain_Load(object sender, EventArgs e)
        {
            FillListProduct();
        }

        private void CmAddToOrder_Click(object sender, EventArgs e)
        {
            PanelOrder.Visible = true;
            OrderItem Item = new OrderItem();
            Item.IdProduct = DgvProductList.SelectedRows[0].Cells[0].Value.ToString();
            Item.NameProduct = DgvProductList.SelectedRows[0].Cells[3].Value.ToString();
            Item.Cost = double.Parse(DgvProductList.SelectedRows[0].Cells[4].Value.ToString());
            Item.Discount = double.Parse(DgvProductList.SelectedRows[0].Cells[5].Value.ToString());
            Item.CountInStorage = int.Parse(DgvProductList.SelectedRows[0].Cells[6].Value.ToString());
            Item.CountInOrder = 1;
            LstOrder.Add(Item);
            OutPutInfo();
        }
        /// <summary>
        /// Вывод информации по сумме заказа и суммы скидки
        /// </summary>
        public void OutPutInfo()
        {
            double Sum = 0, DiscountSum = 0;
            CalcOrder(ref Sum, ref DiscountSum);
            LblSum.Text = $"Сумма заказа (с учетом скидки): {Sum}";
            LblDiscount.Text = $"Скидка: {DiscountSum}";
        }

        private void DgvProductList_CellMouseDown(object sender, DataGridViewCellMouseEventArgs e)
        {
            DgvProductList.ClearSelection();
            DgvProductList[ e.ColumnIndex,e.RowIndex].Selected= true;
            
        }

        private void BtnOrder_Click(object sender, EventArgs e)
        {
            FormOrder Frm = new FormOrder();
            Frm.LstOrder = LstOrder;
            Frm.ShowDialog();
            
            OutPutInfo();
            FillListProduct();
            if(LstOrder.Count == 0)
                PanelOrder.Visible = false;
            
        }
    }
}