Trouble with a simple Strategy Pattern example

Question

The error is:

FirstPattern.Character.Character' does not contain a constructor that takes 0 arguments

Here is the code:

public interface WeaponBehavior
{
    void UseWeapon();
}

class SwordBehavior : WeaponBehavior
{
    public void UseWeapon()
    {
        Console.WriteLine("A sword as plain as your wife.");
    }
}

Then, I have a character class:

public abstract class Character
{
    WeaponBehavior weapon;

    public Character(WeaponBehavior wb)
    {
        weapon = wb;
    }

    public void SetWeapon(WeaponBehavior wb)
    {
        weapon = wb;
    }

    public abstract void Fight();
}



public class Queen : Character
{        
    public Queen(WeaponBehavior wb)
    {
        SetWeapon(wb);
    }

    public override void Fight()
    {

    }
}

I'm not sure what I should be doing with the character class and subclasses. Can you guys nudge me in the right direction?

Answer 1

Since Queen is derived from Character and Character only has a constructor with a WeaponBehavior parameter, you need to explicitly call the base constructor in your Queen constructor - that means the call to SetWeapon you had in there is unnecessary as well:

public Queen(WeaponBehavior wb) : base(wb)
{
}

Alternatively you could offer a default constructor in Character and leave your original code unchanged:

public abstract class Character
{
   WeaponBehavior weapon;

   public Character() { }
   ...