组合模式

Component.cs

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);}

Composite.cs

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);        }    }}

Leaf.cs

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

Program.cs

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("Leaf XYA"));        comp2.Add(new Leaf("Leaf XYB"));        root.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();    }}

运行结果：