设计模式实践-组合模式

场景

站点和仪表目录。

实现代码

组合抽象类：

namespace DesignPatterns.Composite
{
    /// <summary>
    /// 站点组合抽象
    /// </summary>
    public abstract class SiteComponent
    {
        /// <summary>
        /// 组合名称
        /// </summary>
        protected string Name;

        /// <summary>
        /// Initializes a new instance of the <see cref="SiteComponent" /> class.
        /// </summary>
        /// <param name="name">组合名称</param>
        protected SiteComponent(string name)
        {
            this.Name = name;
        }

        /// <summary>
        /// 添加组合
        /// </summary>
        /// <param name="siteComponent">组合对象</param>
        public abstract void Add(SiteComponent siteComponent);

        /// <summary>
        /// 移除组合
        /// </summary>
        /// <param name="siteComponent">组合对象</param>
        public abstract void Remove(SiteComponent siteComponent);

        /// <summary>
        /// 显示组合下的所有元素
        /// </summary>
        /// <param name="depth">本节点深度</param>
        public abstract void Display(int depth);
    }
}

站点类

namespace DesignPatterns.Composite
{
    /// <summary>
    /// 站点组合类
    /// </summary>
    public class Site : SiteComponent
    {
        /// <summary>
        /// 子站点列表
        /// </summary>
        private readonly List<SiteComponent> _sublist = new List<SiteComponent>();

        /// <summary>
        /// Initializes a new instance of the <see cref="Site" /> class.
        /// </summary>
        /// <param name="name">站点名称</param>
        public Site(string name) : base(name)
        {
        }

        /// <summary>
        /// 添加子站点组合
        /// </summary>
        /// <param name="siteComponent">组合对象</param>
        public override void Add(SiteComponent siteComponent)
        {
            this._sublist.Add(siteComponent);
        }

        /// <summary>
        /// 删除子站点组合
        /// </summary>
        /// <param name="siteComponent">组合对象</param>
        public override void Remove(SiteComponent siteComponent)
        {
            this._sublist.Remove(siteComponent);
        }

        /// <summary>
        /// 显示组合下的所有元素
        /// </summary>
        /// <param name="depth">本节点深度</param>
        public override void Display(int depth)
        {
            Console.WriteLine(new string('-', depth) + this.Name);

            foreach (var site in this._sublist)
            {
                site.Display(depth + 2);
            }
        }
    }
}

仪表类

namespace DesignPatterns.Composite
{   
    /// <summary>
    /// 仪表组合类
    /// </summary>
    public class Meter : SiteComponent
    {
        /// <summary>
        /// Initializes a new instance of the <see cref="Meter" /> class.
        /// </summary>
        /// <param name="name">仪表名称</param>
        public Meter(string name) : base(name)
        {
        }

        public override void Add(SiteComponent siteComponent)
        {
            throw new NotImplementedException();
        }

        public override void Remove(SiteComponent siteComponent)
        {
            throw new NotImplementedException();
        }

        /// <summary>
        /// 显示本节点
        /// </summary>
        /// <param name="depth">本节点深度</param>
        public override void Display(int depth)
        {
            Console.WriteLine(new string('-', depth) + this.Name);
        }
    }
}

相关调用

SiteComponent rootSite = new Site("总站");
SiteComponent otherSite01 = new Site("分站1");
otherSite01.Add(new Meter("仪表1"));
otherSite01.Add(new Meter("仪表2"));
rootSite.Add(otherSite01);
rootSite.Add(new Site("分站2"));
rootSite.Add(new Site("分站3"));
SiteComponent otherSite02 = new Site("分站4");
otherSite02.Add(new Meter("仪表1"));
otherSite02.Add(new Meter("仪表2"));
otherSite02.Add(new Meter("仪表3"));
otherSite02.Add(new Meter("仪表4"));
otherSite02.Add(new Meter("仪表5"));
rootSite.Add(otherSite02);
rootSite.Display(1);

Out：

-总站
---分站1
-----仪表1
-----仪表2
---分站2
---分站3
---分站4
-----仪表1
-----仪表2
-----仪表3
-----仪表4
-----仪表5