设计模式之组合模式(Composite Pattern)

设计模式之组合模式(Composite Pattern)

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1.概念
将对象组合成树形结构以表示“部分-整体”的层次结构。它使得客户对单个对象和复合对象的使用具有一致性。
纯粹利用这种模式写程序的不常见，C#中TreeView与TreeNode类已经包装的功能足够强大。TreeNode就是这种模式的典型应用。

2.类图

Model.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace CompositePattern
{
    public class Model
    {
        public string ID
        {
            get;

            set;
           
        }

        public string Name
        {
            get;

            set;
        }
    }
}

AbstractComponect.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace CompositePattern
{
    public abstract class AbstractComponect
    {
        public abstract void Add(AbstractComponect mm);


        public abstract void Delete(AbstractComponect mm);


        public abstract string GetData(int indent);
        protected string _Name = "";
        protected Model _Model = null;
        public AbstractComponect(string name)
        {
            _Name = name;
        }
        public AbstractComponect(string name, Model Model)
        {
            _Name = name;
            _Model = Model;
        }

    }
}

Tree .cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace CompositePattern
{
    public class Tree : AbstractComponect
    {
        private List<AbstractComponect> _list = null;
        public Tree(string name)
            : base(name)
        {
            _list = new List<AbstractComponect>();
        }

        public override void Add(AbstractComponect mm)
        {
            _list.Add(mm);
        }

        public override void Delete(AbstractComponect mm)
        {
            _list.Remove(mm);
        }

        public override string GetData(int indent)
        {
            string s = new String('—', indent) +
                 "树枝名称：" + _Name + "\r\n";

            foreach (AbstractComponect mmc in _list)
            {
                s += mmc.GetData(indent + 2);
            }

            return s;

        }
    }
}

Leaf.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace CompositePattern
{
    public class Leaf : AbstractComponect
    {
       
        public Leaf(string name, Model md)
            : base(name, md)
        {
            
        }

        public override void Add(AbstractComponect mm)
        {
            throw new NotImplementedException();
        }

        public override void Delete(AbstractComponect mm)
        {
            throw new NotImplementedException();
        }

        public override string GetData(int indent)
        {
            return new String('—', indent) +
               "树叶名称：" + _Name +
               "；信息内容：" + _Model.Name + "\r\n";
        }
    }
}

3.测试代码
Tree root = new Tree("树枝1");
root.Add(new Leaf("树叶1.1", new Model() { ID = "1.1", Name = "叶子1" }));
root.Add(new Leaf("树叶1.2", new Model() { ID = "1.2", Name = "叶子2" }));

Tree root2 = new Tree("树枝2");
root2.Add(new Leaf("树叶2.1", new Model() { ID = "2.1", Name = "叶子3" }));
root2.Add(new Leaf("树叶2.2", new Model() { ID = "2.2", Name = "叶子4" }));

root.Add(root2);

this.richTextBox1.Text = root.GetData(1);

3.运行结果

—树枝名称：树枝1
———树叶名称：树叶1.1；信息内容：叶子1
———树叶名称：树叶1.2；信息内容：叶子2
———树枝名称：树枝2
—————树叶名称：树叶2.1；信息内容：叶子3
—————树叶名称：树叶2.2；信息内容：叶子4

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