/// <summary>/// 工厂方法/// </summary>public abstract class Factory{public abstract Compute GetCompute();}public class AddFactory : Factory{public override Compute GetCompute(){return new AddCompute();}}public class JianFaFactory : Factory{public override Compute GetCompute(){return new SubCompute();}}public class ChengFaFactory : Factory{public override Compute GetCompute(){return new ChengFaCompute();}}public class ChuFaFactory : Factory{public override Compute GetCompute(){return new ChuFaCompute();}}/// <summary>/// 计算类/// </summary>public abstract class Compute{protected int number1;public int Number1{get { return number1; }set { number1 = value; }}protected int number2;public int Number2{get { return number2; }set { number2 = value; }}public abstract int GetResult();}/// <summary>/// 加法/// </summary>public class AddCompute : Compute{public override int GetResult(){return number1 + number2;} }/// <summary>/// 减法/// </summary>public class SubCompute : Compute{public override int GetResult(){return number1 - number2;}}/// <summary>/// 乘法/// </summary>public class ChengFaCompute : Compute{public override int GetResult(){return number1 * number2;}}/// <summary>/// 除法/// </summary>public class ChuFaCompute : Compute{public override int GetResult(){return number1 / number2;}}

 static void Main(string[] args){int number1 = 1;int number2 = 2;Factory factory = null;string operate = "+";switch (operate){case "+":factory = new AddFactory();break;case "-":factory = new JianFaFactory();break;case "*":factory = new ChengFaFactory();break;case "/":factory = new ChuFaFactory();break;default:break;}Compute compute = factory.GetCompute();compute.Number1 = number1;compute.Number2 = number2;Console.WriteLine(compute.GetResult());Console.ReadKey();}

3.和简单工厂不同的地方是

(1)简单工厂是由switch直接创建具体的产品对象，而工厂方法是swith延迟创建具体的产品对象，先创建相应的工厂，在延迟创建具体的产品对象

(2)简单工厂只能创建一个工厂，工厂方法可以创建多个工厂

4.工厂方法的好处：

(1)用工厂方法在一个类的内部创建对象通常比直接创建对象更灵活。

(2)Factory Method模式通过面向对象的手法，将所要创建的具体对象的创建工作延迟到了子类，从而提供了一种扩展的策略，较好的解决了这种紧耦合的关系。