组合模式

有时候又叫做部分-整体模式，它使我们树型结构的问题中，模糊了简单元素和复杂元素的概念，客户程序可以像处理简单元素一样来处理复杂元素,从而使得客户程序与复杂元素的内部结构解耦。

代码1：叶子节点

//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);
        }


        public override void LineOfDuty()
        {
            Console.WriteLine("{0} 员工招聘培训管理", 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);
        }

        public override void LineOfDuty()
        {
            Console.WriteLine("{0} 公司财务收支管理", name);
        }

    }

代码2：非叶子节点

 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);
            }
        }

        //履行职责
        public override void LineOfDuty()
        {
            foreach (Company component in children)
            {
                component.LineOfDuty();
            }
        }

    }

代码3：客户端代码

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"));
            comp.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"));
            comp.Add(comp2);


            Console.WriteLine("\n结构图：");

            root.Display(1);

            Console.WriteLine("\n职责：");

            root.LineOfDuty();


            Console.Read();
        }
    }