C# snippets for Software Engineering class

__jegyzetek.txt

FORRÁSOK:
  Witch:
    ftp://witch.pmmik.pte.hu:2001/Tanszeki_anyagok/Rendszer-_es_Szoftvertechnologiai_Tanszek/Szendroi_Etelka/

  Peti repo:
    https://github.com/izzual/karacsonyfazh

  Jani repo:
    https://github.com/dJani97/asp.net-bike-webshop

EGYÉB:
  Szavazás:
    <a href="/VoteForObject.aspx?id=<%#: Item.ID %>">VOTE!</a>

  Megjelenítés:
    GridView, egyszerű datasource-al

_important_imports.cs

using System.Collections.Generic;
using System.IO;
using System.ComponentModel.DataAnnotations;
using System.Data.Entity;
using System.Web.ModelBinding;

Bicycle.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.ComponentModel.DataAnnotations;

namespace BikeStore.Models
{
    public class Bicycle
    {
        public int BicycleID { get; set; }
        [Required, StringLength(60)]
        public string ModelName { get; set; }
        public int Price { get; set; }
        public Nullable<int> CategoryID { get; set; }
        public virtual Category Category { get; set; }
    }
}

BicycleContext.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data.Entity;

namespace BikeStore.Models
{
    public class BicycleContext : DbContext
    {
        public BicycleContext() : base("WebShop") { }
        
        public DbSet<Bicycle> Bicycles { get; set; }
    }
}

BicycleDbUpload.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data.Entity;
using System.IO;

namespace BikeStore.Models
{
    public class BicycleDbUpload : DropCreateDatabaseIfModelChanges<BicycleContext>
    {
        protected override void Seed(BicycleContext context)
        {
            foreach(Category item in ReadCategories())
            {
                context.Categories.Add(item);
            }

            foreach (Bicycle item in ReadBicycles())
            {
                context.Bicycles.Add(item);
            }
        }

        private static List<Bicycle> ReadBicycles()
        {
            StreamReader reader = File.OpenText(HttpContext.Current.Server.MapPath("~/App_Data/bicikli.txt"));
            var bikes = new List<Bicycle>();
            Bicycle bike;
            string[] line;

            while (!reader.EndOfStream)
            {
                line = reader.ReadLine().Split(';');
                bike = new Bicycle()
                {
                    BicycleID = int.Parse(line[0]),
                    ModelName = line[1],
                    Manufacturer = line[2],
                    Type = line[3],
                    Price = int.Parse(line[4]),
                    ImageFile = line[5],
                    CategoryID = int.Parse(line[6])
                };
                bikes.Add(bike);
            }
            reader.Close();
            return bikes;
        }

        private static List<Category> ReadCategories()
        {
            StreamReader reader = File.OpenText(HttpContext.Current.Server.MapPath("~/App_Data/katadat.txt"));
            var categories = new List<Category>();
            Category category;
            string[] line;

            while(!reader.EndOfStream)
            {
                line = reader.ReadLine().Split(';');
                category = new Category()
                {
                    CategoryID = int.Parse(line[0]),
                    CatName = line[1]
                };
                categories.Add(category);
            }
            reader.Close();
            return categories;
        }
    }
}

BikeList.aspx

<%@ Page Title="Bikes" Language="C#" MasterPageFile="~/Site.Master" AutoEventWireup="true" CodeBehind="BikeList.aspx.cs" Inherits="BikeStore.BikeList" %>
<asp:Content ID="Content1" ContentPlaceHolderID="MainContent" runat="server">
<section>

    <div>
        <hgroup>
            <h2> <%: Page.Title %> </h2>
        </hgroup>
    </div>
    <asp:ListView runat="server" ID="lstViewBikes" GroupItemCount="4" ItemType="BikeStore.Models.Bicycle" DataKeyNames="BicycleID" SelectMethod="GetBikes">

        <EmptyDataTemplate>
            <table>
                <tr><td>No data!</td></tr>
            </table>
        </EmptyDataTemplate>

        <EmptyItemTemplate>
            <td> </td>
        </EmptyItemTemplate>

        <GroupTemplate>
            <tr id="itemPlaceholderContainer" runat="server">
                <td runat="server" id="itemPlaceholder"></td>
            </tr>
        </GroupTemplate>

        <ItemTemplate>
            <td runat="server">
                <table>
                    <tr>
                        <td>
                            <a href="BikeDetails.aspx?BicycleID=<%#: Item.BicycleID %>">
                                <img src="/Catalog/Thumbs/<%#: Item.ImageFile %>" width="100" height="75" style="border:solid"/>
                            </a>
                        </td>
                    </tr>
                    <tr>
                        <td>
                            <a href="BikeDetails.aspx?BicycleID=<%#: Item.BicycleID %>">
                                <span> <%#: Item.ModelName %> </span>
                            </a>
                            <br /> 
                            <span> <b>Ár:<b/> <%#: String.Format("{0:c}", Item.Price) %> </span>
                        </td>
                    </tr>
                    <tr>
                       <td>
                           &nbsp;
                       </td>
                    </tr>
                </table>
                <p></p>
            </td>
        </ItemTemplate>

        <LayoutTemplate>
            <table style="width:100%">
                <tbody>
                    <tr>
                        <td>
                            <table id="groupPlaceholderContainer" runat="server" style="width:100%">
                                <tr id="groupPlaceholder"></tr>
                            </table>
                        </td>
                    </tr>
                    <tr><td></td></tr><tr></tr>
                </tbody>
            </table>
        </LayoutTemplate>
    </asp:ListView>
</section>
</asp:Content>

BikeList.aspx.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.ModelBinding;
using BikeStore.Models;

namespace BikeStore
{
    public partial class BikeList : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e) { }

        public IQueryable<Bicycle> GetBikes([QueryString("id")] int? categoryID) {
            var db = new BicycleContext();
            IQueryable<Bicycle> query = db.Bicycles;
            if(categoryID != null && categoryID.HasValue) {
                query = from line in query
                        where line.CategoryID == categoryID
                        select line;
            }
            return query;
        }
    }
}

VoteForBike.aspx

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using BikeStore.Models;

namespace BikeStore {
    public partial class VoteForBike : System.Web.UI.Page {
        protected void Page_Load(object sender, EventArgs e) {

            string requestedID = Request.QueryString["id"];

            if (!String.IsNullOrEmpty(requestedID) && int.TryParse(requestedID, out int bikeID)) {
                var db = new BicycleContext();
                Bicycle bicycle = (from bike in db.Bicycles
                                   where bike.BicycleID == bikeID
                                   select bike).FirstOrDefault();
                bicycle.Votes++;
                db.SaveChanges();
            }
            else {
                Response.Redirect("404.aspx");
            }

            Uri previousUri = Request.UrlReferrer;
            if (previousUri != null)
                Response.Redirect(previousUri.ToString());
            else {
                Response.Redirect("BikeList.aspx");
            }

        }
    }
}

Web.config.xml

<?xml version="1.0" encoding="utf-8"?>
  <connectionStrings>
    <add name="DefaultConnection" connectionString="Data Source=(LocalDb)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\aspnet-BikeStore-20181209105656.mdf;Initial Catalog=aspnet-BikeStore-20181209105656;Integrated Security=True"
      providerName="System.Data.SqlClient" />
    <add name="WebShop" connectionString="Data Source=(LocalDb)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\BikeStore.mdf;Integrated Security=True"
      providerName="System.Data.SqlClient" />
  </connectionStrings>
</configuration>