我如何重构这两个C＃函数来从他们所处理的特定类属性中抽象出它们的逻辑？

Question

我有两个函数，其底层逻辑是相同的，但在一种情况下，它在类上设置一个属性值，在另一种情况下，它设置不同的一个。 如何重写以下两个函数以尽可能多地抽象出算法，以便我可以在一个地方对逻辑进行更改？

SetBillingAddress

private void SetBillingAddress(OrderAddress newBillingAddress)
{
    BasketHelper basketHelper = new BasketHelper(SiteConstants.BasketName);
    OrderAddress oldBillingAddress = basketHelper.Basket.Addresses[basketHelper.BillingAddressID];

    bool NewBillingAddressIsNotOldBillingAddress = ((oldBillingAddress == null) || (newBillingAddress.OrderAddressId != oldBillingAddress.OrderAddressId));
    bool BillingAddressHasBeenPreviouslySet = (oldBillingAddress != null);
    bool BillingAddressIsNotSameAsShippingAddress = (basketHelper.ShippingAddressID != basketHelper.BillingAddressID);
    bool NewBillingAddressIsNotShippingAddress = (newBillingAddress.OrderAddressId != basketHelper.ShippingAddressID);

    if (NewBillingAddressIsNotOldBillingAddress && BillingAddressHasBeenPreviouslySet && BillingAddressIsNotSameAsShippingAddress)
    {
        basketHelper.Basket.Addresses.Remove(oldBillingAddress);
    }

    if (NewBillingAddressIsNotOldBillingAddress && NewBillingAddressIsNotShippingAddress)
    {
        basketHelper.Basket.Addresses.Add(newBillingAddress);
    }

    basketHelper.BillingAddressID = newBillingAddress.OrderAddressId;
    basketHelper.Basket.Save();
}

这是第二个：

SetShippingAddress

private void SetShippingAddress(OrderAddress newShippingAddress)
{
    BasketHelper basketHelper = new BasketHelper(SiteConstants.BasketName);
    OrderAddress oldShippingAddress = basketHelper.Basket.Addresses[basketHelper.ShippingAddressID];

    bool NewShippingAddressIsNotOldShippingAddress = ((oldShippingAddress == null) || (newShippingAddress.OrderAddressId != oldShippingAddress.OrderAddressId));
    bool ShippingAddressHasBeenPreviouslySet = (oldShippingAddress != null);
    bool ShippingAddressIsNotSameAsBillingAddress = (basketHelper.ShippingAddressID != basketHelper.BillingAddressID);
    bool NewShippingAddressIsNotBillingAddress = (newShippingAddress.OrderAddressId != basketHelper.BillingAddressID);

    if (NewShippingAddressIsNotOldShippingAddress && ShippingAddressHasBeenPreviouslySet && ShippingAddressIsNotSameAsBillingAddress)
    {
        basketHelper.Basket.Addresses.Remove(oldShippingAddress);
    }

    if (NewShippingAddressIsNotOldShippingAddress && NewShippingAddressIsNotBillingAddress)
    {
        basketHelper.Basket.Addresses.Add(newShippingAddress);
    }

    basketHelper.ShippingAddressID = newShippingAddress.OrderAddressId;
    basketHelper.Basket.Save();
}

我最初的想法是，如果我可以通过引用传递一个类的属性，那么我可以将之前的函数重写为类似的东西

private void SetPurchaseOrderAddress(OrderAddress newAddress, ref String CurrentChangingAddressIDProperty)

然后调用此函数并将basketHelper.BillingAddressID或basketHelper.ShippingAddressID作为CurrentChangingAddressIDProperty传递，但由于我无法通过引用传递C＃属性，我不知道如何处理此代码以便能够在两个地方重用逻辑。

感谢您给我的任何见解。

Answer 1

您可以传递lambda表达式：

private void SetPurchaseOrderAddress(OrderAddress newAddress, Func<string> addressIDGetter, Action<string> addressIDSetter) 

像这样称呼它：

SetPurchaseOrderAddress(newAddress, () => basketHelper.BillingAddressID, a => basketHelper.BillingAddressID = a);

Answer 2

发送Func和Action，一个用于获取属性，另一个用于再次设置。

private void SetPurchaseOrderAddress(OrderAddress newAddress, 
          Func<BasketHelper, int> getAddId, Action<BasketHelper, int> setAddId) {}

这将给出类似的东西：

SetPurchaseOrderAddress(address, 
    bh => bh.Basket.Addresses[bh.BillingAddressID],
    (bh,s) => bh.BillingAddressID = s);

Answer 3

您可以使用委托创建一个方法，该方法将一些简单的行为（例如设置属性的值）作为参数。 在C＃3.0中，您可以使用lambda表达式轻松创建委托，在C＃2.0中，您可以使用匿名委托来执行类似的操作。

在您的示例中，您将编写一个采用Action<BasketHelper>委托的方法 - 委托允许您指定在初始化之后和保存之前应使用BasketHelper完成的一些操作：

private void SetBasketProperty(Action<BasketHelper> action)  { 
  BasketHelper basketHelper = new BasketHelper(SiteConstants.BasketName); 
  // Code that is repeated for all similar methods

  // Invoke the specific action    
  action(basketHelper);
  basketHelper.Basket.Save(); 
} 

要在C＃3.0中调用此方法，您可以编写如下内容：

SetBasketProperty(basketHelper => {
    basketHelper.ShippingAddressID = newShippingAddress.OrderAddressId;
  });

lambda表达式只是提供了在调用Save之前要运行的代码。