【设计模式】组合模式

定义：将对象组合成树形结构以表示“部分-整体”的层次结构。组合模式使得用户对单个对象和组合对象的使用具有一致性。

范例一：

using System;using System.Collections.Generic;using System.Text;namespace 组合模式{    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);    }    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 Remove(Component c)        {            Console.WriteLine("Cannot remove from a leaf");        }        public override void Display(int depth)        {            Console.WriteLine(new String('-', depth) + name);        }    }    class Composite : Component    {        private List<Component> children = new List<Component>();        public Composite(string name) : base(name) { }        public override void Add(Component c)        {            children.Add(c);        }        public override void Remove(Component c)        {            children.Remove(c);        }        public override void Display(int depth)        {            Console.WriteLine(new String('-', depth) + name);            foreach (Component component in children)            {                component.Display(depth + 2);            }        }            }    class Program    {        static void Main(string[] args)        {            Composite root = new Composite("root");            root.Add(new Leaf("Leaf A"));            root.Add(new Leaf("Leaf B"));            Composite comp = new Composite("Composite X");            comp.Add(new Leaf("Leaf XA"));            comp.Add(new Leaf("Leaf XB"));            root.Add(comp);            Composite comp2 = new Composite("Composite XY");            comp2.Add(new Leaf("Left XYA"));            comp2.Add(new Leaf("Left XYB"));            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.Read();        }    }}

范例二：公司管理系统

using System;using System.Collections.Generic;using System.Text;namespace 组合模式_公司管理系统{    abstract class Company    {        protected string name;        public Company(string name)        {            this.name = name;        }        public abstract void Add(Company c);        public abstract void Remove(Company c);        public abstract void Display(int depth);    }    //具体公司类    class ConcreteCompany : Company    {        private List<Company> children = new List<Company>();        public ConcreteCompany(string name) : base(name) { }        public override void Add(Company c)        {            children.Add(c);        }        public override void Remove(Company c)        {            children.Remove(c);        }        public override void Display(int depth)        {            Console.WriteLine(new string('-', depth) + name);            foreach (Company component in children)            {                component.Display(depth + 2);            }        }    }    //人力资源部    class HRDepartment : Company    {        public HRDepartment(string name) : base(name) { }        public override void Add(Company c)        {                    }        public override void Remove(Company c)        {                    }        public override void Display(int depth)        {            Console.WriteLine(new string('-', depth) + name);        }    }    //财务部    class FinanceDepartment : Company    {        public FinanceDepartment(string name) : base(name) { }        public override void Add(Company c)        {        }        public override void Remove(Company c)        {        }        public override void Display(int depth)        {            Console.WriteLine(new string('-', depth) + name);        }    }    class Program    {        static void Main(string[] args)        {            ConcreteCompany root=new ConcreteCompany("北京总公司");            root.Add(new HRDepartment("总公司人力资源部"));            root.Add(new FinanceDepartment("总公司财务部"));            ConcreteCompany comp = new ConcreteCompany("上海华东分公司");            comp.Add(new HRDepartment("华东分公司人力资源部"));            comp.Add(new FinanceDepartment("华东分公司财务部"));            root.Add(comp);            ConcreteCompany comp1 = new ConcreteCompany("南京办事处");            comp1.Add(new HRDepartment("南京办事处人力资源部"));            comp1.Add(new FinanceDepartment("南京办事处财务部"));            root.Add(comp1);            ConcreteCompany comp2 = new ConcreteCompany("杭州办事处");            comp2.Add(new HRDepartment("杭州办事处人力资源部"));            comp2.Add(new FinanceDepartment("杭州办事处财务部"));            root.Add(comp2);            root.Display(1);            Console.Read();        }    }}