C#:逐行解析 XML

Question

我正在尝试解析 XML 文档并将其转换为 C# 对象。我成功地输入了一些条目，但对于其他条目，我不明白为什么它不起作用。这是示例 xml:

<?xml version="1.0" encoding="UTF-8"?>
<Invoice xmlns="urn:oasis:names:specification:ubl:schema:xsd:Invoice-2" xmlns:cac="urn:oasis:names:specification:ubl:schema:xsd:CommonAggregateComponents-2" xmlns:cbc="urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2" xmlns:ccts="urn:un:unece:uncefact:documentation:2" xmlns:qdt="urn:oasis:names:specification:ubl:schema:xsd:QualifiedDatatypes-2" xmlns:udt="urn:un:unece:uncefact:data:specification:UnqualifiedDataTypesSchemaModule:2">
    <cbc:UBLVersionID>2.1</cbc:UBLVersionID>
    <cbc:CustomizationID>abcd</cbc:CustomizationID>
    <cbc:ProfileID>urn:www.abc.eu:profile:bii05:ver2.0</cbc:ProfileID>
    <cbc:ID>TOSL108</cbc:ID>
    <cbc:IssueDate>2013-06-30</cbc:IssueDate>
    <cbc:InvoiceTypeCode listID="UL122001">38021</cbc:InvoiceTypeCode>
    <cbc:Note>Ordered in our booth at the convention.</cbc:Note>
    <cbc:TaxPointDate>2013-06-30</cbc:TaxPointDate>
    <cbc:DocumentCurrencyCode listID="ISO4217">NOK</cbc:DocumentCurrencyCode>
    <cbc:AccountingCost>Project cost code 123</cbc:AccountingCost>
    <cac:InvoicePeriod>
        <cbc:StartDate>2013-06-01</cbc:StartDate>
        <cbc:EndDate>2013-06-30</cbc:EndDate>
    </cac:InvoicePeriod>
</Invoice>  

我成功获得了所有 cbc 项目，但没有使用 cac。这是 C# 代码:

XmlDocument document = new XmlDocument();
document.LoadXml(model.XmlDocument);

XmlNamespaceManager mgr = new XmlNamespaceManager(document.NameTable);
mgr.AddNamespace("cac", "urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2");
mgr.AddNamespace("cbc", "urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2");
XmlElement docElement = document.DocumentElement;
var a = docElement.SelectSingleNode("cbc:InvoiceTypeCode/@listID", mgr)?.InnerText;
var b = docElement.SelectSingleNode("cbc:TaxCurrencyCode/@listID", mgr)?.InnerText;
var invoice = new Invoice()
{
    UBLVersionId = docElement.SelectSingleNode("cbc:UBLVersionID", mgr)?.InnerText,
    CustomizationID = docElement.SelectSingleNode("cbc:CustomizationID", mgr)?.InnerText,
    ProfileID = docElement.SelectSingleNode("cbc:ProfileID", mgr)?.InnerText,
    InvoiceId = docElement.SelectSingleNode("cbc:InvoiceId", mgr)?.InnerText,
    IssueDate = DateTime.Parse(docElement.SelectSingleNode("cbc:IssueDate", mgr)?.InnerText),
    InvoiceTypeCode = docElement.SelectSingleNode("cbc:InvoiceTypeCode", mgr)?.InnerText,
    InvoiceTypeCode_ListID = docElement.SelectSingleNode("cbc:InvoiceTypeCode/@listID", mgr)?.InnerText,
    TaxPointDate = docElement.SelectSingleNode("cbc:TaxPointDate", mgr)?.InnerText,
    DocumentCurrencyCode = docElement.SelectSingleNode("cbc:DocumentCurrencyCode", mgr)?.InnerText,
    DocumentCurrencyCodeListID = docElement.SelectSingleNode("cbc:DocumentCurrencyCode/@listID", mgr)?.InnerText,
    TaxCurrencyCode = docElement.SelectSingleNode("cbc:TaxCurrencyCode", mgr)?.InnerText,
    TaxCurrencyCodeListID = docElement.SelectSingleNode("cbc:TaxCurrencyCode/@listID", mgr)?.InnerText,
    AccountingCost = docElement.SelectSingleNode("cbc:AccountingCost", mgr)?.InnerText,
    InvoicePeriod = new InvoicePeriod()
    {
        StartDate = DateTime.Parse(docElement.SelectSingleNode("cac:InvoicePeriod/cbc:StartDate", mgr)?.InnerText),
        EndDate = DateTime.Parse(docElement.SelectSingleNode("cac:InvoicePeriod/cbc:EndDate", mgr)?.InnerText)
    }
};  

1. 为什么 InvoicePeriod 解析不起作用？
2. 有没有更有效的方法来解析这样的文档？

Answer 1

使用 System.Xml.Serialization.XmlSerializer 让您的生活更轻松。通过使用此类，您将获得可维护的代码。所以你会得到类似下面的东西:

Invoice invoice;
XmlSerializer serializer = new XmlSerializer(typeof(Invoice));
using (var reader = new StringReader(model.XmlDocument))
{
    invoice = (Invoice)serializer.Deserialize(reader);
}

要避免像您在评论中所说的那样执行 InvalidOperationException，您需要在 Visual Studio Edit> Paste Special> 作为 XML 类粘贴。因此 VS 将为您生成正确的 Invoice 类结构。