Question

greetngs,

i have two classes:

[Serializable]
public class FireGridUnit
{
    public GridUnit FireGridLocation { get; set; }

}

[Serializable]
public class FireResult: FireGridUnit
{
    public bool Hit { get; set; }

    public bool ShipDestroyed { get; set; }

    public Ship.ValidShips DestroyedShipType {get; set;}

    public bool Win { get; set; }
}

as you see FireResult inherits FireGrdUnit.

in my code when i try to use them i get a runtime error:

Unable to cast object of type ‘NietzscheBattleships.FireGridUnit’ to type ‘NietzscheBattleships.FireResult’.

is this because if i am serializing the class has to be independant ie not be inherited?

many thanks.

EDIT:

it happens here:

                    XmlSerializer ss;
                    StringWriter ww;

                    ss = new XmlSerializer(typeof(FireResult));
                    ww = new StringWriter();

                    ss.Serialize(ww, fireGridUnit);

                    MessageBox.Show("hello");

                    MessageBox.Show(ww.ToString());

it gives the error mentioned. if i take this out then it runs but obviously not doing what want it to do.

EDIT: i got it my mistake!

ss.Serialize(ww, fireGridUnit); should be ss.Serialize(ww, fireResult);

thanks.

Answer 1

Nope, you can’t down-cast a FireGridUnit to a FireResult. The other way around is fine. Either you serialized the wrong object or the cast you used on the return value of Deserialize() is wrong.