C#复合模式(Composite Pattern)实例教程
时间：2021-01-27 10:36:54|栏目：.NET代码|点击： 次
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。
