哪个更好 ？？？
public class Order
{
private double _price;
private double _quantity;
public double TotalCash
{
get
{
return _price * _quantity;
}
}
要么
public class Order
{
private double _totalCash;
private double _price;
private double _quantity;
private void CalcCashTotal()
{
_totalCash = _price * _quantity
}
public double Price
{
set
{
_price = value;
CalcCashTotal();
}
}
public double Quantity
{
set
{
_price = value;
CalcCashTotal();
}
}
public double TotalCash
{
get
{
return _totalCash;
}
}
解决方法
有权衡.如果计算简单,不需要很长时间,就把它放在get中.它使您的生活变得更轻松,因为您不用担心总体价格所依赖的每一套物品都会进行检查,这可能会导致错误.
如果计算需要很多时间,那么您也可以采取混合方式.您可以在所有依赖集中设置一个IsDirtyTotalPrice布尔值,然后在get中进行计算并缓存它,以便只需要在需要时计算变量.你不会在集合中进行计算,因为可能会有很多的计算,并且你可以尽可能多地进行计算.
public class Order
{
private double _totalCash;
private double _price;
private double _quantity;
private _IsDirtyTotalCash = true;
private void CalcCashTotal()
{
_totalCash = _price * _quantity
}
public double Price
{
set
{
_price = value;
_IsDirtyTotalCash = true;
}
}
public double Quantity
{
set
{
_price = value;
_IsDirtyTotalCash = true;
}
}
public double TotalCash
{
get
{
if(_IsDirtyTotalCash)
{
_totalCash = CalcTotalCost();
_isDirtyTotalCash = false;
}
return _totalCash;
}
}
}
