Is there a simple way, to get all nodes from an xml document?开发者_JS百科 I need every single node, childnode and so on, to check if they have certain attributes.
Or will I have to crawl through the document, asking for childnodes?
In LINQ to XML it's extremely easy:
XDocument doc = XDocument.Load("test.xml"); // Or whatever
var allElements = doc.Descendants();
So to find all elements with a particular attribute, for example:
var matchingElements = doc.Descendants()
.Where(x => x.Attribute("foo") != null);
That's assuming you wanted all elements. If you want all nodes (including text nodes etc, but not including attributes as separate nodes) you'd use DescendantNodes()
instead.
EDIT: Namespaces in LINQ to XML are nice. You'd use:
var matchingElements = doc.Descendants()
.Where(x => x.Attribute(XNamespace.Xmlns + "aml") != null);
or for a different namespace:
XNamespace ns = "http://some.namespace.uri";
var matchingElements = doc.Descendants()
.Where(x => x.Attribute(ns + "foo") != null);
see here: Iterating through all nodes in XML file
shortly:
string xml = @"
<parent>
<child>
<nested />
</child>
<child>
<other>
</other>
</child>
</parent>
";
XmlReader rdr = XmlReader.Create(new System.IO.StringReader(xml));
while (rdr.Read())
{
if (rdr.NodeType == XmlNodeType.Element)
{
Console.WriteLine(rdr.LocalName);
}
}
In my opinion the simplest solution is using XPath. Also this works if you have .NET 2:
var testDoc = new XmlDocument();
testDoc.LoadXml(str);
var tmp = testDoc.SelectNodes("//*"); // match every element
XDocument.Descendants will return you all the nodes in a flat enumerable.
Check out LINQ to XML. That does what you need.
http://www.hookedonlinq.com/LINQtoXML5MinuteOverview.ashx
You can use the SelectMany
extension for example.
But if you want to check the values you can just use LINQ to create where
-statements.
public void AddWithChildren(XmlNode xnod, Int32 intLevel) //,XmlDocument xmlDoc
{
List<IEnumerable> item = new List<IEnumerable>();
XmlNode xnodWorking;
String strIndent = new string('-', 2 * intLevel);
String strIndent1 = new string('@', 2 * intLevel);
if (xnod.NodeType == XmlNodeType.Element)
{
item.Add(new ListXML(strIndent + xnod.Name, strIndent + xnod.Name, ""));
XmlNamedNodeMap mapAttributes = xnod.Attributes;
foreach (XmlNode xnodAttribute in mapAttributes)
{
item.Add(new ListXML(strIndent1 + xnodAttribute.Name, strIndent1 + xnodAttribute.Name, ""));
}
if (xnod.HasChildNodes)
{
xnodWorking = xnod.FirstChild;
while (xnodWorking != null)
{
AddWithChildren(xnodWorking, intLevel + 1);
xnodWorking = xnodWorking.NextSibling;
}
}
}
}
protected void Page_Load(object sender, EventArgs e)
{
XmlDocument document = new XmlDocument();
string xmlStr;
using (var wc = new WebClient())
{
xmlStr = wc.DownloadString("test.xml");
}
var xmlDoc = new XmlDocument();
xmlDoc.LoadXml(xmlStr);
XmlNode xnod = xmlDoc.DocumentElement;
AddWithChildren(xnod, 1);
}
string AttrNameerr = "err";//find error code in xml
XmlReader rdr = XmlReader.Create(new stem.IO.StringReader(somesXMLtring));//somesXMLtring is xml in string variable we want to find attribute in.
while (rdr.Read())
{
if (rdr.NodeType == XmlNodeType.Element)
{
//Found the new element, now check if the required attribute is present or not. if not, ignore, if yes then display the same
string val = rdr.GetAttribute(AttrNameerr);//AttrNameerr is name of attribute we need to get value of which. here we are searching for error code stored as value of 'err' attribute
if (val != null)
textBox.Text = strResult = "error = " + rdr.GetAttribute(AttrNameerr);
}
}
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