设计模式--组合模式

using System;
using System.Collections.Generic;

// 组件类，可以是叶节点或容器节点的基类
abstract class Component
{
    protected string name;

    public Component(string name)
    {
        this.name = name;
    }

    public abstract void Add(Component component);
    public abstract void Remove(Component component);
    public abstract void Display(int depth);
}

// 叶节点类，表示组合中的叶节点对象
class Leaf : Component
{
    public Leaf(string name) : base(name) { }

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

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

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

// 容器节点类，表示组合中的容器节点对象
class Composite : Component
{
    private List<Component> children = new List<Component>();

    public Composite(string name) : base(name) { }

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

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

    public override void Display(int depth)
    {
        Console.WriteLine(new string('-', depth) + name);

        foreach (Component component in children)
        {
            component.Display(depth + 2);
        }
    }
}

// 客户端代码
class Client
{
    static void Main(string[] args)
    {
        // 创建树状结构
        Composite root = new Composite("Root");
        root.Add(new Leaf("Leaf A"));
        root.Add(new Leaf("Leaf B"));

        Composite composite = new Composite("Composite X");
        composite.Add(new Leaf("Leaf XA"));
        composite.Add(new Leaf("Leaf XB"));

        root.Add(composite);

        Leaf leaf = new Leaf("Leaf C");
        root.Add(leaf);
        root.Remove(leaf);

        // 调用组合对象的方法，执行操作
        root.Display(1);

        Console.ReadLine();
    }
}