# 工厂方法模式

属于创建型模式。
定义一个用于创建对象的接口，让子类决定实例化哪一个类，使一个类的实例化延迟到其子类。
如果新增一个产品，只需要在原有的基础上进行扩展就可以了。

# 类图

创建抽象类和具体的类
创建工厂接口，由具体的工厂类实现接口

# 代码

# 需要实例化的类

	namespace CreationalPatterns_FactoryMethodPattern
	{
	public abstract class Shape
	{
	/// <summary>
	/// 形状
	/// </summary>
	public abstract void MyShape();
	}
	}

	namespace CreationalPatterns_FactoryMethodPattern
	{
	public class Square : Shape
	{
	public override void MyShape()
	{
	Console.WriteLine("Square");
	}
	}
	}

	namespace CreationalPatterns_FactoryMethodPattern
	{
	public class Triangle : Shape
	{
	public override void MyShape()
	{
	Console.WriteLine("Triangle");
	}
	}
	}

# 工厂接口

	namespace CreationalPatterns_FactoryMethodPattern
	{
	public interface IShapeFactory
	{
	/// <summary>
	/// 创建形状
	/// </summary>
	public Shape CreateShape();
	}
	}

# 具体的工厂

	namespace CreationalPatterns_FactoryMethodPattern
	{
	public class SquareFactory : IShapeFactory
	{
	public Shape CreateShape()
	{
	return new Square();
	}
	}
	}

	namespace CreationalPatterns_FactoryMethodPattern
	{
	public class TriangleFectory : IShapeFactory
	{
	public Shape CreateShape()
	{
	return new Triangle();
	}
	}
	}

# 测试

	namespace CreationalPatterns_FactoryMethodPattern
	{
	public class Program
	{
	private static void Main()
	{
	IShapeFactory squareFactory = new SquareFactory();
	IShapeFactory triangleFectory = new TriangleFectory();

	Shape square = squareFactory.CreateShape();
	Shape triangle = triangleFectory.CreateShape();

	square.MyShape();
	triangle.MyShape();
	}
	}
	}

运行结果：
Square
Triangle