HeadFirst 設計模式一及其c#實現

 設計原則一：找出應用中可能需要變化之處，把他們獨立出來，不要把他們和不需變化的代碼混在一起。這樣可以很容易的改動或者封裝需要變化的部分；

設計原則二：針對介面編程；而不是針對實現編程。

 

下邊是c#代碼的實現：

 

 public interface IFlyBehavior<br /> {<br /> void Fly();<br /> }</p><p> public interface IQuackBehavior<br /> {<br /> void Quack();<br /> }</p><p>class FlyNoWay : IFlyBehavior<br /> {<br /> public void Fly()<br /> {<br /> Console.WriteLine("FlyNoWay");<br /> }<br /> }</p><p> class FlyWithWings : IFlyBehavior<br /> {<br /> public void Fly()<br /> {<br /> Console.WriteLine("FlyWithWings");<br /> }<br /> }</p><p>class MuteQuack : IQuackBehavior<br /> {<br /> public void Quack()<br /> {<br /> Console.WriteLine("MuteQuack");<br /> }<br /> }</p><p>class Quacks : IQuackBehavior<br /> {<br /> public void Quack()<br /> {<br /> Console.WriteLine("Quacks");<br /> }<br /> }</p><p> class RockerPowerBehavior : IFlyBehavior<br /> {<br /> public void Fly()<br /> {<br /> Console.WriteLine("RockerPowerBehavior");<br /> }<br /> }</p><p>class Spueak : IQuackBehavior<br /> {<br /> public void Quack()<br /> {<br /> Console.WriteLine("Spueak");<br /> }<br /> }</p><p>public abstract class Duck<br /> {<br /> public IFlyBehavior flyBehavior;<br /> public IQuackBehavior quackBehavior;</p><p> public Duck() { }<br /> public void PerformFly()<br /> {<br /> flyBehavior.Fly();<br /> }<br /> public void PerformBehavior()<br /> {<br /> quackBehavior.Quack();<br /> }<br /> public abstract void Display();<br /> public void Swim()<br /> {<br /> Console.WriteLine("鴨子都會遊泳。");<br /> }<br /> public void SetFly(IFlyBehavior flyBehavior)<br /> {<br /> this.flyBehavior = flyBehavior;<br /> }<br /> public void SetQuack(IQuackBehavior quackBehavior)<br /> {<br /> this.quackBehavior = quackBehavior;<br /> }<br /> }</p><p>class MarllarDuck : Duck<br /> {<br /> public MarllarDuck()<br /> {<br /> flyBehavior = new FlyWithWings();<br /> quackBehavior = new Quacks();<br /> }<br /> public override void Display()<br /> {<br /> Console.WriteLine("I am a Real Marllar Duck");<br /> }<br /> }</p><p>class ModelDuck : Duck<br /> {<br /> public ModelDuck()<br /> {<br /> this.flyBehavior = new FlyNoWay();<br /> this.quackBehavior = new MuteQuack();<br /> }<br /> public override void Display()<br /> {<br /> Console.WriteLine("I am a Model Duck.");<br /> }<br /> }</p><p> class Program<br /> {<br /> static void Main(string[] args)<br /> {<br /> //MarllarDuck marllarDuck = new MarllarDuck();</p><p> //marllarDuck.Display();<br /> //marllarDuck.PerformBehavior();<br /> //marllarDuck.PerformFly();<br /> //marllarDuck.Swim();<br /> Duck duck1 = new ModelDuck();<br /> duck1.PerformFly();<br /> duck1.SetFly(new RockerPowerBehavior());<br /> duck1.PerformFly();</p><p> Console.Read();<br /> }<br /> }<br />