静态工厂模式(StaticFactory pattern)

概述

静态工厂模式又称为简单工厂模式，这个模式甚至不能称为一个模式，我们可能只能称其为一个编程习惯。但它在实际的编程中经常被用到，而且思想也非常简单，可以说是其他工厂模式的一个前导。

类图

计算器示例

namespace FactoryCalc
{
    public interface IOperater
    {
        double Num1
        {
            get;
            set;
        }

        double Num2
        {
            get;
            set;
        }
    
        double GetResult();
    }
}

namespace FactoryCalc
{
    public class AddOperater : IOperater
    {
        public double GetResult()
        {
            return Num1 + Num2;
        }

        public double Num1
        {
            get;
            set;
        }

        public double Num2
        {
            get;
            set;
        }
    }
}

namespace FactoryCalc
{
    public class SubOperater : IOperater
    {
        public double GetResult()
        {
            return Num1 - Num2;
        }

        public double Num1
        {
            get;
            set;
        }

        public double Num2
        {
            get;
            set;
        }
    }
}

namespace FactoryCalc
{
    public class SubOperater : IOperater
    {
        public double GetResult()
        {
            return Num1 - Num2;
        }

        public double Num1
        {
            get;
            set;
        }

        public double Num2
        {
            get;
            set;
        }
    }
}

namespace FactoryCalc
{
    public class MulOperater : IOperater
    {
        public double GetResult()
        {
            return Num1 * Num2;
        }

        public double Num1
        {
            get;
            set;
        }

        public double Num2
        {
            get;
            set;
        }
    }
}

namespace FactoryCalc
{
    public class DivOperater : IOperater
    {
        public double GetResult()
        {
            if (Num2 == 0)
            {
                throw new DivideByZeroException("Num2不能为0.");
            }
            else
            {
                return Num1 / Num2;
            }
        }

        public double Num1
        {
            get;
            set;
        }

        public double Num2
        {
            get;
            set;
        }
    }
}

namespace FactoryCalc
{
    public static class OperaterFactory
    {
    
        public static IOperater CreateOperater(string operater)
        {
            switch (operater)
            {
                case "+":
                    return new AddOperater();
                case "-":
                    return new SubOperater();
                case "*":
                    return new MulOperater();
                case "/":
                    return new DivOperater();
                default:
                    return null;
            }
        }
    }
}

示例代码 FactoryCalc.rar

转载于:https://www.cnblogs.com/wanglj2007/archive/2011/09/19/2181526.html