public OperateInterface CreateOperate(string strOperator)
{
if (strOperator.Equals("+"))
{
OperateInterface operInterf = new OperateAdd(); //如果传进来的是+，定义一个接口operInterf，并且使用OperateAdd()来实例化这个接口
//这时operInterf其实就是一个OperateAdd()的对象
return(operInterf); //这时把operInterf返回给operFac.CreateOperate(),再赋值给operInterface
}
else if (strOperator.Equals("-"))
{
OperateInterface operInterf = new OperateDec();
return(operInterf);
}
else if (strOperator.Equals("*"))
{
OperateInterface operInterf = new OperateRide();
return(operInterf);
}
else if (strOperator.Equals("/"))
{
OperateInterface operInterf = new OperateDiv();
return(operInterf);
}
else if (strOperator.Equals("reciprocal"))
{
OperateInterface operInterf = new OperateRecip();
return(operInterf);
}
return(null);
}
public static Operation CreateOperate(string operate)
{
Operation oper = null;
switch (operate)
{
case "+":
oper = new OperateAdd();
break;
case "-":
oper = new OperateDelete();
break;
case "*":
oper = new OperateMultiple();
break;
case "/":
oper = new OperateDevide();
break;
}
return(oper);
}
