c# - 帮助使用 Linq 查询 XML

Question

我有这个 XML，我希望能够提取订单号、项目、数量、项目价格(本金、税金，也可以是其他)。这是 XML(见下文)。我遇到的问题是 ItemPrice。有了它，您可以从 0 到许多价格组成部分、税收、本金等。我怎样才能将它们拉出到单行输出中？

现在我可以获得订单号、商品号、数量...但是当我提取价格时，我会得到一条税和原则。

另一个问题是，如果在某些情况下没有税收会怎样？我会得到一个空引用，不是吗？我想尝试处理这些并替换为 0。非常感谢任何建议。

XML:

<?xml version="1.0" encoding="UTF-8"?>
<SettlementReport>
<Order>
  <AmazonOrderID>105-6982537-6258888</AmazonOrderID> 
  <ShipmentID>MyShipmentIDTest1234</ShipmentID> 
  <MarketplaceName>Amazon.com</MarketplaceName> 
    <Fulfillment>
      <MerchantFulfillmentID>MyTestFulFillID12345</MerchantFulfillmentID> 
      <PostedDate>2008-12-15T19:33:04+00:00</PostedDate> 
        <Item>
          <AmazonOrderItemCode>13350774331938</AmazonOrderItemCode> 
          <SKU>U1409</SKU> 
          <Quantity>1</Quantity> 
            <ItemPrice>
                <Component>
                      <Type>Principal</Type> 
                      <Amount currency="USD">0.15</Amount> 
                  </Component>
                <Component>
                      <Type>Tax</Type> 
                      <Amount currency="USD">0.02</Amount> 
                  </Component>
              </ItemPrice>
          </Item>
          <Item>
            <AmazonOrderItemCode>13350774331939</AmazonOrderItemCode> 
            <SKU>U14010</SKU> 
            <Quantity>2</Quantity> 
            <ItemPrice>
                <Component>
                      <Type>Principal</Type> 
                      <Amount currency="USD">0.30</Amount> 
                  </Component>
                <Component>
                      <Type>Tax</Type> 
                      <Amount currency="USD">0.04</Amount> 
                  </Component>
              </ItemPrice>
          </Item>
      </Fulfillment>
  </Order>
</SettlementReport>

我的代码:

            XDocument customer = XDocument.Load(@"C:\LinqToXML.xml");

            var orders = from amznorders in customer.Root.Elements("Order")
                         from amznfulfill in amznorders.Elements("Fulfillment")
                         from amznitems in amznfulfill.Elements("Item")
                         from amznitemprc in amznitems.Elements("ItemPrice").Elements("Component")
                             select new
                                        {
                                            OrderNumber = (string)amznorders.Element("AmazonOrderID"),
                                            ItemNumber = (string)amznitems.Element("AmazonOrderItemCode"),
                                            QTY = (string)amznitems.Element("Quantity"),
                                            //This is where I need help...if type = Principal set PriceAmount else Set PriceTax?//
                                            PriceAmount = (string)amznitemprc.Element("Amount")
                                            //Address1 = (string)address1.Element("Address1")
                                     };

            foreach (var order in orders)
            {
                Console.WriteLine("Order: {0} ItemNumber: {1} QTY: {2} PriceAmount: {3} ", order.OrderNumber, order.ItemNumber, order.QTY, order.PriceAmount);

            }

Answer 1

可行，但确实有点尴尬。我可能会使用一对 let 变量来保存我想要的子组件(假设您只需要这两个特定值)。

由于 Where 子句的问题，编辑删除了 lets。我认为选择中的 Where 没有问题，但它可能有同样的问题。

var orders = from amznorders in customer.Root.Elements("Order")    
             from amznfulfill in amznorders.Elements("Fulfillment")    
             from amznitems in amznfulfill.Elements("Item")    
             from amznitemprc in amznitems.Elements("ItemPrice").Elements("Component")    
             select new    
                         {    
                                OrderNumber = (string)amznorders.Element("AmazonOrderID"),    
                                ItemNumber = (string)amznitems.Element("AmazonOrderItemCode"),    
                                Qty = (string)amznitems.Element("Quantity"),
                                PriceAmount = amznitemprc.Where(xe => xe.Element("Type").Value == "Principal").FirstOrDefault().Value,
                                TaxAmount = amxnitemprc.Where(xe => xe.Element("Type").Value == "Tax").FirstOrDefault() == null ? string.Empty : amxnitemprc.Where(xe => xe.Element("Type").Value == "Tax").FirstOrDefault(),
                                TotalItemPrice = amznitemprc.Sum(xe => decimal.Parse(xe.Element("Amount").Value)).ToString(),
                                //Address1 = (string)address1.Element("Address1")    
                         };