Discussion :

[JerryOne3]

bonjour a tous.

alors voila, on a ici un programme pour gérer un magasin, ou chaque classe représente un filiale du magasin. Nous prendrons pour l'exemple la filiale "Book".

je crée donc dans mon program.cs une liste de livres, basée sur ArrayList (obligatoire pour l'exercice).

et je cherche a pouvoir les classer par Sort en utilisant un Icomparer, mais j'ai une erreur que je n'arrive pas a résoudre.

Voila d'abord la classe Product :

Code :

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using System;
using System.Collections.Generic;
using System.Text;
 
namespace bookstore2
{
    public class Product
    {
        private uint _ID;
        private string _Name;
        private decimal _Price;
 
        public uint ID
        {
            get { return _ID; }
            set { _ID = value; }
        }
        public string Name
        {
            get { return _Name; }
            set { _Name = value; }
        }
        public decimal Price
        {
            get { return _Price; }
            set { _Price = value; }
        }
 
        public Product (uint id, string name, decimal price)
        {
            ID = id;
            Name = name;
            Price = price;
        }
 
        public Product()
        {
            ID = 0;
            Name = "";
            Price = 0;
        }
 
        public override string ToString()
        {
            return ID + "\t" + Name + "\t" + Price + "\t";
        }
    }
}

la classe Book maintenant :

Code :

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using System;
using System.Collections.Generic;
using System.Text;

namespace bookstore2
{
    public class Book : Product
    {
        private string _Author;
        private string _Publisher;
        public BookType type;

        public enum BookType {Baking, Scientific}
        
        public string Author
        {
            get { return _Author; }
            set { _Author = value; }
        }
        public string Publisher
        {
            get { return _Publisher; }
            set { _Publisher = value; }
        }

        public override string ToString()
        {
            return base.ToString() + Author + "\t" + Publisher + "\t" + type + "\n";
        }

        public Book(uint ID, string name, decimal price, string author, string publisher, BookType booktype) : base(ID,name,price)
        {
            Author = author;
            Publisher = publisher;
            type = booktype;
        }

        public Book() : base()
        {
            Author = "";
            Publisher = "";
        }
    }
    public class CompareNoms : IComparer<Book>
    {
        public int Compare(Book B1, Book B2)
        {
            int i = B1.Name.CompareTo(B2.Name);
            return i;
        }
    }
}

enfin la classe program :

Code :

Sélectionner tout - Visualiser dans une fenêtre à part

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using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;
using bookstore2;

namespace ConsoleApplication
{
    class Program
    {
        public static void Main (string[] args)
        {
            ArrayList bookArray = new ArrayList();
            string choice="";
            while (true)
            {
                Console.Write("Please select an operation: \n");
                Console.Write("Add (add)\nRemove (remove)\nPrint (print)\nAuthor (author)\nSort (sort)\n");
                
                choice = Console.ReadLine();
                #region switch cases
                switch (choice)
                {
                    #region add
                    case "add":
                    {
                        Console.WriteLine("insert the book id");
                        uint bookid = Convert.ToUInt32(System.Console.ReadLine());
                        Console.WriteLine("insert the book name");
                        string bookname = System.Console.ReadLine(); 
                        Console.WriteLine("insert its price ");
                        decimal bookprice = Convert.ToDecimal(System.Console.ReadLine()); 
                        Console.WriteLine("insert the author name");
                        string authorname = System.Console.ReadLine();
                        Console.WriteLine("insert the publisher");
                        string publisher = System.Console.ReadLine();
                        Console.WriteLine("insert the type : ");
                        Book.BookType type = Book.BookType.Baking;
                        int index = 1;
                        foreach (Book.BookType b in Enum.GetValues(type.GetType()))
                        {
                            Console.WriteLine(index + " : " + b);
                            index += 1;
                        }
                        index = Convert.ToInt32(Console.ReadLine());
                        if (index == 1)
                            type = Book.BookType.Baking;
                        else if (index == 2)
                            type = Book.BookType.Scientific;
                        else
                            Console.WriteLine("Ben ca sera baking alors! nan mais!");
                        index = 1;
                        bookArray.Add(new Book(bookid, bookname, bookprice, authorname, publisher, type));
                        Console.WriteLine("There are so far {0} book(s) created\n", bookArray.Count);
                        break;
                    }
                    #endregion add

                    #region remove
                    case "remove":
                    {
                        if (bookArray.Count==0)
                        {
                            Console.Write("no book to remove\n");
                            break;
                        }
                        Console.Write("insert the book ID to remove\n");
                        uint ID = Convert.ToUInt32(System.Console.ReadLine());
                        int index = 0;
                        int indextemp = 0;
                        foreach (Book item in bookArray)
                        {
                            if (item.ID == ID)
                            {
                                indextemp = index;
                                break;
                            }
                            index++;
                        }
                        Console.WriteLine("The book {0} has been removed from database", bookArray[indextemp].ToString());
                        bookArray.RemoveAt(indextemp);
                        Console.WriteLine("There are so far {0} book(s) created\n", bookArray.Count);
                        indextemp = 0;
                        index--;
                        break;
                    }
                    #endregion remove

                    #region print
                    case "print":
                    {
                        foreach (Book item in bookArray)
                        {
                            System.Console.WriteLine(item.ToString());
                        }
                        break;
                    }
                    #endregion print

                    #region search by author
                    case "author":
                    {
                        Console.WriteLine("insert the author name");
                        string authorname = System.Console.ReadLine();

                        int sumofbooks = 0;
                        foreach (Book item in bookArray)
                        {
                            if (item.Author == authorname)
                            {
                                Console.WriteLine(item.ToString());
                                sumofbooks++;
                            }
                        }
                        if (sumofbooks == 0)
                        {
                            Console.WriteLine("no book of this author found.");
                        }
                        break;
                    }
                    #endregion search by author

                    case "sort":
                    {
                        bookArray.Sort(CompareNoms());
                        break;
                    }
                    
                    default:
                    {
                        Console.Write("please choose a valid operation\n");
                        break;
                    }
                }
                #endregion switch cases
            }
        }
    }
}

En gras, a la fin de Book et vers la fin de Program, la classe héritant Icomparer et ma tentative de classement via sort.

Merci d'avance

[maxtiger]

c'est normal,
Arraylist.sort() utilise System.Collections.ICompare non pas System.Collections.Generic.ICompare

-----------------------------------------

La meilleur solution: à la place de l'ArrayList il faut créer une List<BOOK>

-------------- dans ton code-----------

public static void Main(string[] args)
{
List<Book> bookArray = new List<Book>();
string choice = "";
while (true)
..
..

case "sort":
{

IComparer<Book> myComparer = new CompareNoms();
bookArray.Sort(myComparer);

break;
}

[JerryOne3]

super, merci beaucoup a toi, je vais tenter de progresser maintenant !