How to Cast a List to a List of

Question

I have made a my own class with its own properties, and added that to a List<ownclass>. For working reasons, I have to cast that to a List<object>. On the other hand I have to cast it back (in a later workaround).

How would this look like?

1

What code do you have already? – Mark Oct 22 '18 at 12:52

Renato · Answer 1 · 2018-10-22T13:30:43.603

The following code demonstrates the procedure of casting a list of a custom class to a list of objects, casting the list of objects back into a list of the custom class and reading from the final list.

class MyClass
{
    public int MyNumber { get; set; }
}

class Program
{

    static void Main(string[] args)
    {
        var myList = new List<MyClass>()
        {
            new MyClass { MyNumber = 99 },
            new MyClass { MyNumber = 123 }
        };

        var objectList = myList.Cast<object>().ToList();
        var myConvertedList = objectList.Cast<MyClass>().ToList();

        foreach (int n in myConvertedList.Select(c => c.MyNumber))
            Console.WriteLine(n);

        Console.ReadLine();

    }
}

score -1 · Answer 2 · answered Oct 22 '18 at 12:55

-1

to cast it to a list of objects:

List<object> objects = ownClassList.Select( o => (object)o).ToList();

to cast it back :

List<ownclass> ownClassList = objects.Select( o=> (ownclass) o).ToList();

edit: you have to import system.linq

answered Oct 22 '18 at 12:55

Cruces

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1

Why not use `.Cast – Enigmativity Oct 22 '18 at 12:57
1

And what you're doing is converting the list, not casting it. – Enigmativity Oct 22 '18 at 13:00
What I'm doing is exactly the same as .Cast on a collection (such as List) which implements IEnumerable , https://stackoverflow.com/questions/7132500/whats-the-benefit-of-cast-over-select – Cruces Oct 22 '18 at 14:21

How to Cast a List to a List of

2 Answers2