需要澄清帮助 - C# / OOP / Inheritance / 多态性 / 多个 ZE40489CD1E37102E35469C9

Question

Architecture of my self structured problem

- Hero class (string Name, int Health, int Gold)

- Mage class (string Name, int Health, int Gold, int Intelect) - every Mage is a Hero

- Archimage class (string Name, int Health, int Gold, int Intelect, int SpellsCast) - every Archimage is a Mage

- Warrior class ( string Name, int Health, int Gold, int Strength) - every Warrior is a Hero

- Champion class (string Name, int Health, int Gold, int Intelect, int DemonsSlain) - every Champion is a Warrior

---

Now the part that puzzles me: I want to implement hybrid classes that inherit from both branches of the class tree.

- Paladin class (string Name, int Health, int Gold, int Intelect, int Strength) - every Paladin is a Mage and a Warrior

- Monk class (string Name, int Health, int Gold, int Intelect, int Strength, int SpellsCast, int DemonsSlain) - every Monk is an Archimage and a Champion.

And lets do two diagonal:

- BattleMage class (string Name, int Health, int Gold, int Intelect, int Strength, int SpellsCast) - every BattleMage is an Archimage and a Warrior.

- SpellBreaker class (string Name, int Health, int Gold, int Intelect, int Strength, int DemonsSlain) - every SpellBreaker is an Mage and a Champion.

---

The code is self explanatory after running it.

namespace Heroes_Of_Inheritance_And_Polymorphism
{
    class Program
    {
        static void Main(string[] args)
        {
            Hero Hero1 = new Hero("Arthur", 100, 50);
            Hero1.ShowStatus();

            Console.WriteLine("##########");

            Mage Hero2 = new Mage("Arthur", 100, 50, 120);
            Hero2.ShowStatus();

            Console.WriteLine("##########");

            Warrior Hero3 = new Warrior("Arthur", 100, 50, 120);
            Hero3.ShowStatus();

            Console.WriteLine("##########");

            Archimage Hero4 = new Archimage("Arthur", 100, 50, 120, 1000);
            Hero4.ShowStatus();

            Console.WriteLine("##########");

            Champion Hero5 = new Champion("Arthur", 100, 50, 120, 1000);
            Hero5.ShowStatus();
        }
    }

    public class Hero
    {
        public string Name;
        public int Health;
        public int Gold;

        public Hero(string name, int health, int gold)
        {
            this.Name = name;
            this.Health = health;
            this.Gold = gold;
        }

        public virtual void ShowStatus()
        {
            Console.WriteLine($"I am a Hero called {Name}, with {Health} health and {Gold} gold pieces!");
        }
    }

    public class Mage : Hero
    {
        int Intelect; 

        public Mage(string name, int health, int gold, int intelect) : base(name, health, gold)
        {
            this.Intelect = intelect;
        }

        public override void ShowStatus()
        {
            base.ShowStatus();
            Console.WriteLine($"I, {Name}, have now become a Mage with {Intelect} intelect.");
        }
    }

    public class Archimage : Mage
    {
        int SpellsCast;

        public Archimage(string name, int health, int gold, int intelect, int spellscast) : base(name, health, gold, intelect)
        {
            this.SpellsCast = spellscast;
        }

        public override void ShowStatus()
        {
            base.ShowStatus();
            Console.WriteLine($"I, {Name}, am a wise Archimage that has cast {SpellsCast} spells.");
        }
    }

    public class Warrior : Hero
    {
        int Strength;

        public Warrior(string name, int health, int gold, int strength) : base(name, health, gold)
        {
            this.Strength = strength;
        }

        public override void ShowStatus()
        {
            base.ShowStatus();
            Console.WriteLine($"I, {Name}, have now become a Warrior with {Strength} strength.");
        }
    }

    public class Champion : Warrior
    {
        int DemonsSlain;

        public Champion(string name, int health, int gold, int strength, int demonsslain) : base(name, health, gold, strength)
        {
            this.DemonsSlain = demonsslain;
        }

        public override void ShowStatus()
        {
            base.ShowStatus();
            Console.WriteLine($"I, {Name}, am a strong Champion that has slain {DemonsSlain} demons.");
        }
    }
}

So far so good, but this

public class Paladin : Warrior, Mage
    {
        public Paladin(string name, int health, int gold, int Intelect, int Strength) 
            : base(name, health, gold, strength)
        {
        }
    }

obviously will not work.

I am getting a sense I should be using interfaces. I am not entirely sure how I can extract the needed parameters from multiple classes in a singular interface, reusing their constructors in this case also boggles my mind.

Any pointers, viable solutions, critiques or completely different approaches are welcomed!

Best regards! ^^

Answer 1

As @DavidG mentioned in the comment above is not possible to have multiple inheritance in C# , but there are some things you can do depending of the scenario:

• First review the all architecture, to be sure that you need a multiple inheritance, sometimes with a little change we can save us a lot of research/implementation time.
• If after review everything you still need the multiple inheritance there are some patterns that you can use, like interfaces implementations or mixin pattern .

You can think in mixin like add functionalities to your object, lets say you can encapsulate a lot of functionalities for your different cases like run , jump , attack , etc... ( Mixin ).

Other option to achieve this is simulate multiple inheritance with an interface , you can think in an interface like a set of properties and functions , that your object implement and by implement that implies that you need to provide a definition for those functions inside the class that implements that interface ( Interfaces ).

There is a proposal to allow method implementations inside an interface for C#-8 but still is just a proposal, hope the above helps to clarify the issue and point you to the right direction.