Class Array with [] and IEnumerable

Question

I created a class that's something like this:

    public class MovieTheaterList
    {
        public DateTime Date { get; private set; }
        public int NumTheaters { get; private set; }
        public Theater[] Theaters { get; private set; }
    }

    public class Theater
    {
        public string Name;
    }

I want to be able to add items to the Theaters array of the MovieTheaterList class, but when I try to access it, it is showing up as an IEnumerable type and there is no Add() method?

I'm used to using arrays in structs and classes in C/C++, but how can I add a new item to the array in .NET 3.5?

Answer 1

Expose Theaters as an IList, not an array, and you'll be able to add / remove items from it. e.g.

public class MovieTheaterList
{
    // don't forget to initialize the list backing your property
    private List<Theater> _theaterList = new List<Theater>(); 

    public DateTime Date { get; private set; }
    public int NumTheaters { get; private set; }

    // set is unnecessary, since you'll just be adding to / removing from the list, rather than replacing it entirely
    public IList<Theater> Theaters { get { return _theaterList; } }
}

Answer 2

Use

List<Theater> Theaters { get; private set; }

instead of an array of Theaters. You can initialize it using

Theaters = new List<Theater>();

In C# using lists is generally preferred over using arrays. You can easily convert between to an array using ToArray() but this way you don't have to worry about correctly sizing the array at creation time or, more importantly, resizing during execution.

Answer 3

How about having the MovieTheatreClass extend a Generic List, for this functionality.

public class MovieTheatreList : List<Theatre>
{
    public DateTime Date { get; private set; }
}

public class Theatre
{
    public string Name;
}

This way, you get all the built in stuff of the List (like Count instead of having a separate NumOfTheatres property to maintain).