# 工厂模式

属于创建型模式，是常用的设计模式之一。
工厂模式提供了一种将对象的实例化过程封装在工厂类中的方式。通过使用工厂模式，可以将对象的创建与使用代码分离，提供一种统一的接口来创建不同类型的对象。

优点

缺点

# 类图

	namespace CreationalPatterns_FactoryPattern
	{
	public interface IShape
	{
	/// <summary>
	/// 形状
	/// </summary>
	public void MyShape();
	}
	}

	namespace CreationalPatterns_FactoryPattern
	{
	public interface IEffect
	{
	/// <summary>
	/// 效果
	/// </summary>
	public void MyEffect();
	}
	}

	namespace CreationalPatterns_FactoryPattern
	{
	public class RoundShape : IShape
	{
	public void MyShape()
	{
	Console.WriteLine("圆形");
	}
	}
	}

	namespace CreationalPatterns_FactoryPattern
	{
	public class SquareShape : IShape
	{
	public void MyShape()
	{
	Console.WriteLine("正方形");
	}
	}
	}

	namespace CreationalPatterns_FactoryPattern
	{
	internal class ExplodeEffect : IEffect
	{
	public void MyEffect()
	{
	Console.WriteLine("爆炸");
	}
	}
	}

	namespace CreationalPatterns_FactoryPattern
	{
	internal class TransparencyEffect : IEffect
	{
	public void MyEffect()
	{
	Console.WriteLine("透明");
	}
	}
	}

	namespace CreationalPatterns_FactoryPattern
	{
	public class CreateFactory
	{
	/// <summary>
	/// 储存已生成的对象，循环利用
	/// </summary>
	private static Dictionary<string, object> Cache = new Dictionary<string, object>();

	/// <summary>
	/// 创建对象
	/// </summary>
	/// <typeparam name="T"></typeparam>
	/// <param name="className"> 类名 & lt;/param>
	/// <returns></returns>
	private static T CreateObject<T>(string className) where T : class
	{
	if (Cache.ContainsKey(className))
	{
	return Cache[className] as T;
	}
	else
	{
	Type type = Type.GetType(className);
	object temp = Activator.CreateInstance(type);
	Cache.Add(className, temp);
	return temp as T;
	}
	}

	/// <summary>
	/// 创建形状
	/// </summary>
	/// <param name="shapeName"> 形状 & lt;/param>
	/// <returns></returns>
	public static IShape GetShape(string shapeName)
	{
	// 命名规则：CreationalPatterns_FactoryPattern. + 形状 + Shape
	string className = string.Format("CreationalPatterns_FactoryPattern.{0}Shape", shapeName);
	return CreateObject<IShape>(className);
	}

	/// <summary>
	/// 创建效果
	/// </summary>
	/// <param name="effectName"> 效果 & lt;/param>
	/// <returns></returns>
	public static IEffect GetEffect(string effectName)
	{
	// 命名规则：CreationalPatterns_FactoryPattern. + 效果 + Effect
	string className = string.Format("CreationalPatterns_FactoryPattern.{0}Effect", effectName);
	return CreateObject<IEffect>(className);
	}
	}
	}

	namespace CreationalPatterns_FactoryPattern
	{
	public class Program
	{
	private static void Main()
	{
	CreateFactory.GetShape("Round").MyShape();
	CreateFactory.GetShape("Square").MyShape();
	CreateFactory.GetEffect("Explode").MyEffect();
	CreateFactory.GetEffect("Transparency").MyEffect();
	}
	}
	}

运行结果：
圆形
正方形
爆炸
透明