享元模式

using System;

using System.Collections.Generic;

namespace MyApp

{

class Program

{

static void Main()

{

Instances instances = new Instances();

Class2 c2 = (Class2)instances.CreateInstance("Class2");

c2.Output();

Class1 c1 = (Class1)instances.CreateInstance("Class1");

c1.Output();

Console.ReadKey();

}

}

abstract class BaseClass

{

public abstract void Output();

}

class Class1 : BaseClass

{

public override void Output()

{

Console.WriteLine("Class1");

}

}

class Class2 : BaseClass

{

public override void Output()

{

Console.WriteLine("Class2");

}

}

class Instances

{

Dictionary<string, BaseClass> containers = new Dictionary<string, BaseClass>();

public Instances()

{

containers.Add("Class1", new Class1());

containers.Add("Class2", new Class2());

}

public BaseClass CreateInstance(string key)

{

return containers[key];

}

}

}