C＃制作不同類型對象的數組

Question

初學者在這里。 我試圖找到一種方法，當它們不是同一類型的對象時，如何在不始終使用“ array [0] as ClassName”的情況下訪問數組中的對象的屬性。 無需詳細答案。 您也可以向我推薦/引導我到哪里去閱讀這些東西，因為也許答案就在我眼前，但由於我是初學者，所以我將無法識別它。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Vezba_9_object_ecercises
{
    class Program
    {
        static void Main(string[] args)
        {

            object[] books = new object[2];

            books[0] = new SomeBooks("Book_1", "Good", 22);
            Console.WriteLine((books[4] as SomeBooks).name); // working
           // Console.WriteLine((books[4].name); // not working, how to make it work

            books[1] = new OtherBooks("Book_2", "Bad", 2);
            Console.WriteLine((books[4] as OtherBooks ).name); // working
          //  Console.WriteLine((books[4].name); // not working, how to make it work

        }
    }
    public class SomeBooks
    {
        public SomeBooks(string _name, string _likability, int _numberOfPages)
        {
            name = _name;
            likability = _likability;
            numberOfPages = _numberOfPages;
        }

        public string name { get; set; }
        public string likability { get; set; }
        public int numberOfPages { get; set; }


    }
    public class OtherBooks
    {
        public OtherBooks(string _name, string _likability, int _numberOfAuthors)
        {
            name = _name;
            likability = _likability;
            NumberOfAuthors = _numberOfAuthors;
        }

        public string name { get; set; }
        public string likability { get; set; }
        public int NumberOfAuthors { get; set; }


    }
}

Answer 1

您可以使SomeBook和OtherBook類從Book基類（或接口）繼承。 這將允許您將它們存儲在類型為Book[]而不是object[]的數組中。 您可以通過這種方式訪問​​繼承的屬性，例如Name和Likability，而無需強制轉換。

public class Book
{
    public string Name { get; set; }
    public string Likability { get; set; }
}

public class SomeBook : Book
{
    public int NumberOfPages { get; set; }
}

public class OtherBook : Book
{
    public int NumberOfAuthors { get; set; }
}

但是我反對這樣做的必要性。 問問自己這是否設計過度。 您可能只有一個Book類，該類允許其他值均為null。

public class Book
{
    public string Name { get; set; }
    public string Likability { get; set; }
    public int? NumberOfPages { get; set; }
    public int? NumberOfAuthors { get; set; }
}

Answer 2

您的數組類型必須是一個接口，每個元素的類型必須是一個繼承該接口的類。

public interface IBook
{
    string Name { get; set; }
    string Likability { get; set; }
}

public class SomeBook : IBook
{
    public string Name { get; set; }
    public string Likability { get; set; }
    public int NumberOfPages { get; set; }
}

public class OtherBook : IBook
{
    public string Name { get; set; }
    public string Likability { get; set; }
    public int NumberOfAuthors { get; set; }
}

public class Books
{
    public Books()
    {
        IBook[] books = new IBook[2] {
            new SomeBook(),
            new OtherBook()
        };

        for (int i = 0; i < books.Length; i++)
        {
            switch (books[i].GetType().Name)
            {
                case "SomeBook":
                    int numberOfPages = ((SomeBook)books[i]).NumberOfPages;
                    break;

                case "OtherBook":
                    int numberOfAuthors = ((OtherBook)books[i]).NumberOfAuthors;
                    break;
            }
        }
    }
}