如何加载内联DTD以用于XDocument？

Question

我有一个问题,关于如何将文档类型定义包含在XML文件中,或者从WP7中加载到XDocument中的XML文件中.我有与此类似的DTD文件:

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE root [
 <!ELEMENT root (Person*)>

 <!ELEMENT Person (Name*, Description*)>
 <!ELEMENT Name (#PCDATA)>
 <!ELEMENT Description (#PCDATA)>

 <!ENTITY egrave "&#232;">
 <!ENTITY eacute "&#233;">
 <!ENTITY euro  "&#8364;">
]>

我需要将此DTD添加到XML中,以便捕获特殊字符,例如é.我使用以下方法从Web获取XML以在Linq中使用:

private void PhoneApplicationPage_Loaded(object sender, RoutedEventArgs e)
{
  string documentUrl = "http://www.example.com";

  WebClient client = new WebClient();

  client.OpenReadCompleted += new OpenReadCompletedEventHandler(client_OpenReadCompleted);
  client.OpenReadAsync(new Uri(documentUrl, UriKind.Absolute));
}

void client_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)
{
  Stream str = e.Result;

  XDocument data = XDocument.Load(str);

  // Saving the XML to the file system for later use
  IsolatedStorageFile isoFile = IsolatedStorageFile.GetUserStoreForApplication();
  IsolatedStorageFileStream isoStream = new IsolatedStorageFileStream("my.xml", FileMode.OpenOrCreate, isoFile);
  StreamWriter sw = new StreamWriter(isoStream);
  XmlWriter xw = XmlWriter.Create(isoStream);

  data.Save(xw);

  // Creating a list to populate a listbox
  List<MyObject> list1 = new List<MyObject>();

  items = (from query in data.Descendants("Person")
    select new MyObject()
    {
    // Doing stuff here...
    }).ToList();

  listBox1.ItemsSource = items;

}

如果DTD是内联的,即在实际的XML本身中,XDocument似乎不会传递XML.我已经尝试了许多基于这篇文章使用XDocumentType的方法,但我无法弄清楚.我怎样才能做到这一点？

Answer 1

您需要在读取XML文档时启用DTD处理.为此,请使用XmlReader适当的设置:

var settings = new XmlReaderSettings { DtdProcessing = DtdProcessing.Parse };
XmlReader reader = XmlReader.Create(str, settings);
XDocument data = XDocument.Load(reader);

如果要将DTD设置为外部,则需要XmlResolver在设置中指定a :

var settings = new XmlReaderSettings
{
    DtdProcessing = DtdProcessing.Parse,
    XmlResolver = /* some resolver here */,
};

默认值XmlResolver是在XmlUrlResolver不使用凭据的情况下解析URL.您可能需要考虑从本地源解析DTD.为此,您可以使用预先填充的XmlPreloadedResolver.