使用LINQ to XML解析XML？

Question

我尝试使用Linq在C＃中解析XML。

这是我正在解析的XML：

 <Credit>
 <LoanApp>

  <LoanAppRq PaymentCall="True" Personal="True" Type="Finance">

    <Applicant>
      <Personal>
        <Individuals>
          <Individual Type="Applicant">
            <GivenName>
              <FirstName>test</FirstName>
              <LastName>tester</LastName>
            </GivenName>


            <ContactInfo>

              <Address Type="Current">
                <StreetNumber>6</StreetNumber>
                <StreetName>alton AVE</StreetName>
                <City>PHILADELPHIA</City>
                <State>PA</State>
                <Zip>19142</Zip>
                <TimeAtLocation>
                  <Year>6</Year>
                  <Month>0</Month>
                </TimeAtLocation>
              </Address>

              <Address Type="Previous">
                <StreetNumber>83</StreetNumber>
                <StreetName>Main Street</StreetName>
                <StreetExtra>12</StreetExtra>
                <City>Irvine</City>
                <State>CA</State>
                <Zip>92695</Zip>
                <Country>USA</Country>
                <TimeAtLocation>
                  <Year/>
                  <Month>3</Month>
                </TimeAtLocation>
              </Address>
            </ContactInfo>

这是我解析它的代码：

        parsed_xml.LoadXml(dto.xml);
        XElement xelement = XElement.Load(stream);

        IEnumerable<XElement> Credit = xelement.Elements();
        foreach (var item in Credit)
        {

           dt.BORROWERFIRSTNAME = item.Element("LoanApp").Element("LoanAppRq").Element("Applicant").Element("Personal").Element("Individuals").Element("Individual").Element("GivenName").Element("FirstName").Value;
           dt.BORROWERLASTNAME= item.Element("LoanApp").Element("LoanAppRq").Element("Applicant").Element("Personal").Element("Individuals").Element("Individual").Element("GivenName").Element("LastName").Value;
         }

这段代码给了我名字和姓氏。

1. 首先，我想知道这是否是解析的正确方法？
2. 第二，如果我想获得当前地址或以前的地址，该如何获得？ 同样，在某些情况下，先前的地址可能不存在。

我已将此网站用作学习参考。

http://www.dotnetcurry.com/showarticle.aspx?ID=564

Answer 1

对于像您这样的没有复杂名称空间的深层XML层次结构，我更喜欢System.Xml.XPath名称空间中的XPathSelectElements 。

假设您的xelement元素具有问题中所显示的XML，则可以执行以下操作：

foreach (var individual in xelement.XPathSelectElements("LoanApp/LoanAppRq/Applicant/Personal/Individuals/Individual"))
{
    // Get the first and last name.
    var BORROWERFIRSTNAME = (string)individual.XPathSelectElement("GivenName/FirstName");
    var BORROWERLASTNAME = (string)individual.XPathSelectElement("GivenName/LastName");

    // Get the XElement for the current address.
    var currentAddress = individual.XPathSelectElements("ContactInfo/Address[@Type='Current']")
                                   .FirstOrDefault();
    // Extract its properties, checking for a missing current address if necessary.
    var currentZip = (currentAddress == null ? null : (string)currentAddress.Element("Zip"));

    // Get the XElement for the previous address.
    var previousAddress = individual.XPathSelectElements("ContactInfo/Address[@Type='Previous']")
                                    .FirstOrDefault();
    // Extract its properties, checking for a missing previous address if necessary.
    var previousZip = (previousAddress == null ? null : (string)previousAddress.Element("Zip"));

    // Process the borrower names and addresses as required.
}

从Linq到XML的等效项是：

foreach (var individual in xelement.Elements("LoanApp")
                                   .Elements("LoanAppRq")
                                   .Elements("Applicant")
                                   .Elements("Personal")
                                   .Elements("Individuals")
                                   .Elements("Individual"))
{
    // Get the first and last name.
    var BORROWERFIRSTNAME = (string)individual.Elements("GivenName")
                                              .Elements("FirstName")
                                              .FirstOrDefault();
    var BORROWERLASTNAME = (string)individual.Elements("GivenName")
                                             .Elements("LastName")
                                             .FirstOrDefault();

    // Get the XElement for the current address.
    var currentAddress = individual.Elements("ContactInfo").Elements("Address").Where(e => (string)e.Attribute("Type") == "Current").FirstOrDefault();
    // Extract its properties, checking for a missing current address if necessary.
    var currentZip = (currentAddress == null ? null : (string)currentAddress.Element("Zip"));

    // Get the XElement for the previous address.
    var previousAddress = individual.Elements("ContactInfo").Elements("Address").Where(e => (string)e.Attribute("Type") == "Previous").FirstOrDefault();
    // Extract its properties, checking for a missing previous address if necessary.
    var previousZip = (previousAddress == null ? null : (string)previousAddress.Element("Zip"));

    // Process the borrower names and addresses as required.
}

如您所见，它看起来有点复杂。

Answer 2

使用Descendant()和Descendants()代替

foreach (var item in Credit)
{
    dt.BORROWERFIRSTNAME = item.Descendant("FirstName").Value;
    dt.BORROWERLASTNAME= item.Descendant("LastName").Value;
}