简单工厂模式

简介

用一个单独的类来负责实例化不同的对象。

代码示例

    public abstract class Operation
    {
        public double NumA;
        public double NumB;

        public abstract double GetResult();
    }

    public class AddOperationSampleFactory : Operation
    {
        public override double GetResult()
        {
            return base.NumA + base.NumB;
        }
    }

    public class SubOperationSampleFactory : Operation
    {
          public override double GetResult()
        {
            return base.NumA - base.NumB;
        }
    }
    
    // 简单工厂
    public class OperationSampleFactory
    {
        public static Operation CreateOperation(string oper)
        {
            Operation operation = null;
            switch(oper)
            {
                case "+" :
                    oper = new AddOperationSampleFactory();
                    break;
                case "-" :
                    oper = new SubOperationSampleFactory();
                    break;
                default : 
                    break;
            }
        }
    }

    static void Main(string[] args)
    {
        // 简单工厂
        var oper = OperationSampleFactory.CreateOperation("+");
        oper.NumA = 1;
        oper.NumB = 2;
        oper.GetResult();

        Console.Read();
    }

学习笔录——大话设计模式——简单工厂模式

原文：https://www.cnblogs.com/caiyangcc/p/13034186.html