I have this xml that i am reading from a url which when i viewsource looks like this:
<xml>
<root>
<item>
<id>1</id>
<name>Testing</name>
</item>
<item>
<id>2</id>
<name>Testing2</name>
</item>
</root>
</xml>
when i ran the code below it keep saying root element is missing? i do have a root element.
public void myfunction()
{
WebRequest request = WebRequest.Create("http://www.site.com/file.xml");
WebResponse response = request.GetResponse();
Stream dataStream = response.GetResponseStream();
string[] arr = XDocument.Load(dataStream).Root.Descendants("Name").Elements().Select(element => element.Value).ToArray(); //error says root element missing
foreach (var item in arr)
{
MessageBox.Show(item.ToString());
}
}
There is no Name element in your xml file. Xml is case-sensitive. You should use lower-case name:
string[] arr = XDocument.Load(dataStream).Root
.Descendants("name")
.Select(name => (string)name)
.ToArray();
BTW your name elements do not have nested elements.
UPDATE: If you want to get values of name elements, then simply cast these elements to string. You can also use Select(name => name.Value) here. Just don't try to get nested elements of name - they don't have any.
Related
I have 2 XML Files and I want to get all the XNodes , which are in both files, only based on their same Attribute "id".
This is how an XML File looks like:
<parameters>
<item id="57">
<länge>8</länge>
<wert>0</wert>
</item>
<item id="4">
<länge>8</länge>
<wert>0</wert>
</item>
<item id="60">
<länge>8</länge>
<wert>0</wert>
</item>
</parameters>
Given a second XML File which looks like this:
<parameters>
<item id="57">
<länge>16</länge>
<wert>10</wert>
</item>
<item id="144">
<länge>16</länge>
<wert>10</wert>
</item>
</parameters>
Now I only want the XNode with the ID=57, since it is available in both files. So the output should look like this:
<item id="57">
<länge>8</länge>
<wert>0</wert>
</item>
I already did intersect both files like this:
aDoc = XDocument.Load(file);
bDoc = XDocument.Load(tmpFile);
intersectionOfFiles = aDoc.Descendants("item")
.Cast<XNode>()
.Intersect(bDoc.Descendants("item")
.Cast<XNode>(), new XNodeEqualityComparer());
This only seems to work, when all the descendant Nodes are the same. If some value is different, it won't work. But I need to get this to work on the same Attributes, the values or the descendants doesn't matter.
I also tried to get to the Attributes and intersect them, but this didn't work either:
intersectionOfFiles = tmpDoc
.Descendants(XName.Get("item"))
.Attributes()
.ToList()
.Intersect(fileDoc.Descendants(XName.Get("item")).Attributes()).ToList();
Am I missing something or is this a completely wrong approach?
Thanks in advance.
You should create your own IEqualityComparer that compares XML attributes you want:
public class EqualityComparerItem : IEqualityComparer<XElement>
{
public bool Equals(XElement x, XElement y)
{
return x.Attribute("id").Value == y.Attribute("id").Value;
}
public int GetHashCode(XElement obj)
{
return obj.Attribute("id").Value.GetHashCode();
}
}
which you would then pass to XML parsing code:
var intersectionOfFiles = aDoc.Root
.Elements("item")
.Intersect(
bDoc.Root
.Elements("item"), new EqualityComparerItem());
I also changed some parts of your XML parsing code (XElement instead of XNode since "item" is XML element and "id" is XML attribute).
I read multiple feed from many sources with C# Console, and i have this code where i load XML From sources:
XmlDocument doc = new XmlDocument();
doc.Load(sourceURLX);
XElement xdoc = XElement.Load(sourceURLX);
How to get enclosure url and show as variable?
If I understand your question correctly (I'm making a big assumption here) - you want to select an attribute from the root (or 'enclosing') tag, named 'url'?
You can make use of XPath queries here. Consider the following XML:
<?xml version="1.0" encoding="utf-8"?>
<root url='google.com'>
<inner />
</root>
You could use the following code to retrieve 'google.com':
String query = "/root[1]/#url";
XmlDocument doc = new XmlDocument();
doc.Load(sourceURLX);
String value = doc.SelectSingleNode(query).InnerText;
Further information about XPath syntax can be found here.
Edit: As you stated in your comment, you are working with the following XML:
<item>
<description>
</description>
<enclosure url="blablabla.com/img.jpg" />
</item>
Therefore, you can retrieve the url using the following XPath query:
/item[1]/enclosure[1]/#url
With xml like below
<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
<channel>
<title>title</title>
<link>https://www.link.com</link>
<description>description</description>
<item>
<title>RSS</title>
<link>https://www.link.com/xml/xml_rss.asp</link>
<description>description</description>
<enclosure url="https://www.link.com/media/test.wmv"
length="10000"
type="video/wmv"/>
</item>
</channel>
</rss>
You will get url by reading attribute
var document = XDocument.Load(sourceURLX);
var url = document.Root
.Element("channel")
.Element("item")
.Element("enclosure")
.Attribute("url")
.Value;
To get multiple urls
var urls = document.Descendants("item")
.Select(item => item.Element("enclosure").Attribute("url").Value)
.ToList();
Using foreach loop
foreach (var item in document.Descendants("item"))
{
var title = item.Element("title").Value;
var link = item.Element("link").Value;
var description = item.Element("description").Value;
var url = item.Element("enclosure").Attribute("url").Value;
// save values to database
}
I'm trying to extract data from provided xml and add that to object using XmlReader, but I noticed on nodes without value, I get "\n " instead.
Example xml:
<Items>
<Item>
<NodeA>Some Value</NodeA>
<NodeB>N</NodeB>
<NodeC />
</Item>
<Item>
...
</Item>
</Items>
Part of my modified C#:
while (sub_reader.ReadToFollowing("Item"))
{
var item = new Item();
sub_reader.ReadToFollowing("NodeA");
sub_reader.Read();
item.NodeA = sub_reader.Value;
sub_reader.ReadToFollowing("NodeB");
sub_reader.Read();
item.NodeB = sub_reader.Value;
sub_reader.ReadToFollowing("NodeC");
sub_reader.Read();
item.NodeC = sub_reader.Value; //This return "\n "
this.Items.Add(item);
}
Is there any function/convenient way that work the above but return null or empty string when <NodeC /> happens? The real xml is much larger and I don't want to do if else on each of them.
Any suggestion is appreciated. Thanks!
Rather than calling Read followed by taking Value property, use ReadElementContentAsString method:
sub_reader.ReadToFollowing("NodeA");
item.NodeA = sub_reader.ReadElementContentAsString();
sub_reader.ReadToFollowing("NodeB");
item.NodeB = sub_reader.ReadElementContentAsString();
sub_reader.ReadToFollowing("NodeC");
item.NodeC = sub_reader.ReadElementContentAsString();
Using XDocument <NodeC/> return string.Empty. Here dotNetFiddle
string xml = #"<Items>
<Item>
<NodeA>Some Value</NodeA>
<NodeB>N</NodeB>
<NodeC />
</Item>
<Item>
<NodeA>Some 2223Value</NodeA>
<NodeB>2223N</NodeB>
<NodeC>12344</NodeC>
</Item>
</Items>";
XDocument doc = XDocument.Parse(xml);
var result = doc.Root.Descendants("NodeC");
foreach(var item in result)
{
Console.WriteLine(item.Value);
}
If you want to deserialize the XDocument to some object you can check this answer: How do I deserialize XML into an object using a constructor that takes an XDocument?
public static MyClass FromXml (XDocument xd)
{
XmlSerializer s = new XmlSerializer(typeof(MyClass));
return (MyClass)s.Deserialize(xd.CreateReader());
}
I have to extract a part of an XML. My XML file can contain thousands of nodes and I would like to get only a part of it and have this part as an xml string.
My XML structure:
<ResponseMessage xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
<ErrorResponse>
<Code>SUCCESS</Code>
<Message>Success</Message>
</ErrorResponse>
<OutputXml>
<Response>
<Product>
<child1>xxx</child1>
<child2>xxx</child2>
...
</Product>
<Product>
<child1>xxx</child1>
<child2>xxx</child2>
...
</Product>
...
</Response>
</OutputXML>
</ResponseMessage>
I'm getting the XML from a webservice like that:
...
System.Net.WebResponse wResponse = req.GetResponse();
reqstream = wResponse.GetResponseStream();
System.IO.StreamReader reader = new System.IO.StreamReader(reqstream);
System.Xml.Linq.XDocument xmlResponse = System.Xml.Linq.XDocument.Parse(reader.ReadToEnd());
Then I tried to put the XML in a generic collection to process it using linq:
int startIndex = 0;
int nbItem = 25;
System.Text.StringBuilder outputXml = new System.Text.StringBuilder();
System.Collections.Generic.IEnumerable<System.Xml.Linq.XElement> partialList =
xmlResponse.Elements("Response").Skip(startIndex).Take(nbItem);
foreach (System.Xml.Linq.XElement x in partialList)
{
outputXml.Append(x.ToString());
}
My problem is that my list is always empty.
You can use an LINQ To Xml by using the following code:
IEnumerable<XElement> elements = xmlResponse.Root.Element("OutputXml").Element("Response").Elements("Product");
foreach(XElement element in elements)
{
// Do Work Here
}
This will filter the list down to just products and it will select them correctly without using an index. Using indexes with xml is not the greatest idea because the xml can change.
You can use XPathEvaluate to read a subtree.
If your list is empty, chances are it is namespace problem, so you did not account for this namespace in your code xmlns:i="http://www.w3.org/2001/XMLSchema-instance". XDocument/XElement cannot resolve namespaces automatically.
See this topic on how to use namespaces with LINQ-to-XML.
I have the following XML structure:
<?xml version="1.0" encoding="utf-8"?>
<xml>
<root>
<Item>
<taxids>
<string>330</string>
<string>374</string>
<string>723</string>
<string>1087</string>
<string>1118</string>
<string>1121</string>
</taxids>
</Item>
</root>
</xml>
I need to get all the string nodes from the xml file to a string variable, like this:
var query = from ip in doc.XPathSelectElements("xml/root/Item")
where ip.XPathSelectElement("taxid").Value == "723"
select ip.XPathSelectElements("taxids").ToString();
But I am getting the following in one row of the variable query:
"System.Xml.XPath.XPathEvaluator+<EvaluateIterator>d__0`1[System.Xml.Linq.XElement]"
I want to get a string like this:
<taxids><string>330</string><string>374</string><string>723</string><string>1087</string><string>1118</string><string>1121</string></taxids>
Is this possible?
Thanks!
I would suggest you something like:
var values = from ids in doc.XPathSelectElements("/xml/root/Item/taxids")
from id in ids.XPathSelectElements("string")
where id.Value.Contains("723")
select ids.ToString();
var result = string.Join("", values);
The value variable will contain all the taxids, which have at least one string child with value 723.
Another variant, which doesn't use XPath for the children checking:
var values = from ids in doc.XPathSelectElements("/xml/root/Item/taxids")
from id in ids.Elements("string")
where id.Value.Contains("723")
select ids.ToString();
var result = string.Join("\n", values);
var doc = XDocument.Parse(#"<?xml version=""1.0"" encoding=""utf-8""?>
<xml>
<root>
<Item>
<taxids>
<string>330</string>
<string>374</string>
<string>723</string>
<string>1087</string>
<string>1118</string>
<string>1121</string>
</taxids>
</Item>
</root>
</xml>");
var query = doc.XPathSelectElement("xml/root/Item/taxids");
Console.WriteLine(query);