- 组合模式
将对象组合成树形结构以表示"部分-整体"的层次结构。组合模式是的用户对单个对象和组合对象的使用具有一致性。
//对象的声明接口
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);
}
//叶子
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);
}
}
//树枝
class Composite:Component
{
//1.声明组件数组
private List<Component>children = new List<Component>();
public Component(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);
}
}
}
//客户端调用
static void Main(string[] args)
{
//1.声明主干组件,并添加两个叶子
Composite root = new Composite("root");
root.Add(new Leaf("Leaf A"));
root.Add(new Leaf("Leaf B"));
//2.添加分支,并给分支添加叶子，将分支添加到主干上
Composite comp = new Composite("Composite X");
comp.Add(new Leaf("Leaf XA"));
comp.Add(new Leaf("Leaf XB"));
root.Add(comp);
//3.添加分支,并给分支添加叶子，将分支添加到主干上
Composite comp2 = new Composite("Composite XY");
comp2.Add(new Leaf("Leaf XYA"));
comp2.Add(new Leaf("Leaf XYB"));
root.Add(comp2);
//显示总的样式
root.Display(1);
Console.Read();
}
-
透明方式与安全方式
- 透明模式：叶节点与枝节点对于外界是没有分别的，它们具备对外一致的接口。但是问题也是很明显，因为Leaf 类本身不具备 Add(),Remove() 方法的功能，所以实现它是没有意义的。
- 安全模式：Component 接口中不去声明 Add() 和 Remove() 方法，那么子类的 Leaf 就不需要去实现它，而是在 Composite 声明所有用来管理子类对象的方法，不过由于不够透明，所以树叶和树枝类将不具有相同的接口。客户端的调用需要相应的判断，带来的不便。
实际应用
abstract class Company
{
protected string name;
public Company(string name)
{
this.name = name;
}
public abstract void Add(Company c);//添加
public abstract void Remove(Company c);//减少
public abstract void Display(Company c);//展示
public abstract void LineOfDuty();//履行职责
}
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);
}
}
public override void LineOfDuty()
{
foreach(Company component in children)
{
component.LineOfDuty();
}
}
}
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()
{
Console.WriteLine(new String('-',depth) + name);
}
public override void LineOfDuty()
{
Console.WriteLine("{0}",name);
}
}
class FinanceDepartment :Company
{
public FinanceDepartment(string name):base(name)
{}
public override void Add(){}
public override void Remove(){}
public override void Display()
{
Console.WriteLine(new String('-',depth)+ name);
}
public override void LineOfDuty()
{
Console.WriteLine("{0}",name);
}
}
static void Main(string[] args)
{
ConcreteCompany root = new ConcreteCompany("总公司");
root.Add(new HRDepartment("hr"));
root.Add(new FinanceDepartment("Final"));
ConcreteCompany comp = new ConcreteCompany("上海分公司");
comp.Add(new HRDepartment("hr"));
comp.Add(new FinanceDepartment("Final"));
root.Add(comp);
ConcreteCompany com1 = new ConcreteCompany("沈阳办事处");
com1.Add(new HRDepartment("hr"));
com1.Add(new FinanceDepartment("Final"));
comp.Add(com1);
ConcreteCompany com2 = new ConcreteCompany("大连办事处");
com2.Add(new HRDepartment("hr"));
com2.Add(new FinanceDepartment("Final"));
comp.Add(com2);
Console.WriteLine("\n 结构图:")
root.Display(1);
Console.WriteLine("\nDuty:")
root.LineOfDuty();
Console.Read();
}
