What is the best way to implement this composite GetHashCode()

Question

I have a simple class:

public class TileName {
    int Zoom, X, Y;

    public override bool Equals (object obj)
    {
        var o = obj as TileName;
              


        

Answer 1

public override int GetHashCode ()
{
    return (Zoom.ToString() + "-" + X.ToString() + "-" + Y.ToString()).GetHashCode();
}