组合模式

Composite_Model

抽象类Component适当情况下实现所有类公共接口的默认行为。声明一个接口用于管理和访问Component的子部件

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Composite_Model
{
    abstract class Component
    {
        protected string name;
        public Component(string name)
        {
            this.name = name;
        }
        public abstract void Add(Component c);
        public abstract void Remove(Component c);
        public abstract void DisPlay(int depth);
    }
}

Leaf在组合中表示叶节点对象，叶节点没有子节点（叶子类）

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Composite_Model
{
    class Leaf : Component
    {
        public Leaf(string name) : base(name)
        {

        }
        public override void Add(Component c)
        {
            Console.WriteLine("Cannot add to a leaf");
        }

        public override void DisPlay(int depth)
        {
            Console.WriteLine(new String('-',depth)+name);
        }

        public override void Remove(Component c)
        {
            Console.WriteLine("Cannot remove from a leaf");
        }
    }
}

Composite为枝节点行为，用来存储子部件，在Component接口中实现与子部件有关的操作、如Add Remove。（分支类）

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Composite_Model
{
    class Composite : Component
    {
        private IList<Component> children = new List<Component>();
        public Composite(string name) : base(name)
        {

        }
        public override void Add(Component c)
        {
            children.Add(c);
        }

        public override void DisPlay(int depth)
        {
            Console.WriteLine(new String('-',depth) + name);
            foreach (Component c in children)
            {
                c.DisPlay(depth + 2);
            }
        }

        public override void Remove(Component c)
        {
            children.Remove(c);
        }
    }
}

客户端

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Composite_Model
{
    class Program
    {
        static void Main(string[] args)
        {
            Composite root = new Composite("root");
            root.Add(new Leaf("LeafA"));
            root.Add(new Leaf("LeafB"));
            Composite comp = new Composite("Composite X");
            comp.Add(new Leaf("Leaf XA"));
            comp.Add(new Leaf("Leaf XB"));
            Composite comp2 = new Composite("Composite XY");
            comp2.Add(new Leaf("Leaf XYA"));
            comp2.Add(new Leaf("Leaf XYB"));
            root.Add(comp);
            comp.Add(comp2);
            root.Add(new Leaf("Leaf C"));
            Leaf leaf = new Leaf("Leaf D");
            root.Add(leaf);
            root.Remove(leaf);

            root.DisPlay(1);
            Console.ReadKey();
        }
    }
}