《大话设计模式》学习笔记1：简单工厂模式

public class Operation
{
public double NumberA { get; set; }
public double NumberB { get; set; }
public virtual double GetResult()
{
　　　　　　 return 0;
}
}

public class AddOperation:Operation
{
public override double GetResult()
{
return NumberA + NumberB;
}
}

public class OperationFactory
{
public static Operation CreateOperate(string operate)
{
Operation operation;
switch(operate)
{
case "+":
operation = new AddOperation();
break;
case "-":
operation = new SubOperation();
break;
default :
operation = null;
break;
}
return operation;
}
}

class Program
{
static void Main(string[] args)
{
Operation operation = OperationFactory.CreateOperate("+");
oper.NumberA = 1;
oper.NumberB = 2;
Console.WriteLine(operation.GetResult());
}
}