Static field problem (error CS0120) in c#

Question

I have to vrite an override function for my function DajGlos(), but I get back error CS0120 (An object reference is required for the non-static field, method, or property). How can I fix this?

My code:

 static void Main(string[] args)
        {
            Pies pies = new Pies("Reksio", "ssaki", "lądowe", 50);

            Pies.Przedstaw("Reksio", "ssaki", "lądowe");
            Pies.DajGlos();
        }


    abstract class Zwierze
    {
        private static string Rodzina { get; set; }
        private static string Grupa { get; set; }
        private static string Imie { get; set; }

        public static void Przedstaw(string Imie, string Rodzina, string Grupa)
        {
            Console.WriteLine("Jestem " + Imie + ", rodzina: " + Rodzina + ", grupa: " + Grupa);
        }

        public abstract void DajGlos();

    }

    class Pies : Zwierze
    {
        public Pies(string Imie, string Rodzina, string Grupa, int dlugoscOgona)
        {
            
        }
        int dlugoscOgona;

        public override void DajGlos()
        {
            Console.WriteLine("Bark!");
        }
    }```

Because DajGlos is not static, unlike Przedstaw. So you need to refer to `pies` - the instance of the Pies class - in order to use it. — ADyson, Dec 15 '20 at 22:19

score 0 · Answer 1 · answered Dec 15 '20 at 22:18

DajGlos is an instance method, so as the error message says, you need to call it on a specific instance (in your case - pies), not on the class itself. I.e.:

Pies pies = new Pies("Reksio", "ssaki", "lądowe", 50);
Pies.Przedstaw("Reksio", "ssaki", "lądowe");
pies.DajGlos(); // Here!

score 0 · Accepted Answer · answered Dec 15 '20 at 22:20

ClassName.StaticMethodName(...) is for accessing static methods.
ObjectName.NonStaticMethodName(...) is for accessing non-static methods.
The line Pies.DajGlos(); is ClassName.NonStaticMethodName(...) which is not allowed.
I guess what you were trying to do is: pies.DajGlos();.

Static field problem (error CS0120) in c#

2 Answers2