Question

Maybe a confusing title, what I’m after is a class, which only has certain amount of instantiations. Still confused?

What I’m actually after is a list of star ratings(none, half, one, one and a half) etc. So I need a class (or maybe a struct?) which has two fields, value and string representation (for now anyway, leading to other fields; url of image etc). And I need a container for these, a List, ObservColl, IEnumerable, just something to contain them.

But I don’t want the class to be instantiable by anything, except the container object, but still have the class available as a type to set as a field on another class.

Is this possible? Or am I going to have to sacrifice something along the way?

Answer 1

I hope this is what you want:

Make the class public or internal (as you need it), but the constructor private:

public class MyClass
{
    private MyClass() { }
}

Then create a public or internal static method in the class to get your list:

public class MyClass
{
    // ...
    public static List<MyClass> GetList()
    {
        List<MyClass> list = new List<MyClass>();
        list.Add(new MyClass());
        // ...
        return list;
    }
}

You can now only get a list via this method. List<MyClass> a = MyClass.GetList(); If you want you can implement it with a static property and privat static field, too:

public class MyClass
{
    // ...
    static MyClass()
    {
        myList = new List<MyClass>();
        myList.Add(new MyClass());
        // ...
    }
    private static List<MyClass> myList = null;
    public static List<MyClass> MyList
    {
        get { return myList; }
    }
}