C#复合模式(Composite Pattern)实例教程

本文以一个简单实例的形式讲述了c#复合模式。分享给大家供大家参考。具体实现方法如下：

一般在显示树形结构时，复合模式有很好的体现。本文实例显示如下部门结构：

如上图所示，有的节点包含子节点，有的节点不包含子节点。不管是什么节点，每个节点就代表一个部门。

首先设计一个关于部门的抽象基类。

public abstract class departmentcomponent
{
    public string name { private set; get; }
    public departmentcomponent(string name)
    {
      this.name = name;
    }
    public virtual void printsupervisorof(int spacing)
    {
      for (int counter = 0; counter < spacing; counter++)
      {
        console.write(" ");
      }
      console.writeline(name);
    }
}

以上，通过构造函数给属性赋值，通过printsupervisorof(int spacing)方法打印出节点的名称。

接下来设计包含子节点的节点。该类维护着departmentcomponent类型的集合，提供方法向这个集合中添加节点或从集合中删除节点。

public class departmentcomposite : departmentcomponent
{
    private ilist<departmentcomponent> employees;
    public departmentcomposite(string name) : base(name)
    {
      employees = new list<departmentcomponent>();
    }
    public void adddepartment(departmentcomponent e)
    {
      employees.add(e);
    }
    public void removedepartment(departmentcomponent e)
    {
      employees.remove(e);
    }
    public override void printsupervisorof(int spacing)
    {
      base.printsupervisorof(spacing);
      foreach (departmentcomponent e in employees)
      {
        e.printsupervisorof(spacing + 1);
      }
    }
}

以上 printsupervisorof(int spacing)方法重写了抽象基类的方法，不仅把本节点的名称打印出来，还使用递归把所有子节点的名称显示出来。

最后设计部包含子节点的节点。

public class department : departmentcomponent
{
    public department(string name) : base(name)
    {
      
    }
    public override void printsupervisorof(int spacing)
    {
      base.printsupervisorof(spacing);
    }
}

客户端部分。

class program
{
    static void main(string[] args)
    {
      departmentcomposite salesdepartment1 = new departmentcomposite("销售部1");
      department zhangsan = new department("张三");
      department lisi = new department("李四");
      departmentcomposite salesdepartment2 = new departmentcomposite("销售部2");
      departmentcomposite specialdepartment = new departmentcomposite("销售部2特别行动组");
      department wangwu = new department("王五");
      department zhaoliu = new department("赵六");
      departmentcomposite salesdepartment = new departmentcomposite("销售部");
      salesdepartment.adddepartment(salesdepartment1);
      salesdepartment.adddepartment(salesdepartment2);
      salesdepartment1.adddepartment(zhangsan);
      salesdepartment1.adddepartment(lisi);
      salesdepartment2.adddepartment(specialdepartment);
      specialdepartment.adddepartment(wangwu);
      specialdepartment.adddepartment(zhaoliu);
      salesdepartment.printsupervisorof(0);
      console.readkey();
    }
}

程序运行结果如下图所示：

希望本文所述对大家c#程序设计的学习有所帮助。