How to Get an XML Element from XDocument using LINQ ?
Suppose I have an XDocument Named XMLDoc which is shown below:
<Contacts>
<Node>
<ID>123</ID>
<Name>ABC</Name>
</Node>
<Node>
<ID>124</ID>
<Name>DEF</Name>
</Node>
</Contacts>
XElement Contacts = from xml2 in XMLDoc.Elements("Contacts").Elements("Node")
where xml2.Element("ID").Value == variable
select xml2;
But I am getting Error "Object Reference is NOT to set....."
How to get a particular Node from a XML file using LINQ?
I want to update some values in that node.
How can this be done?
test.xml:
<?xml version="1.0" encoding="utf-8"?>
<Contacts>
<Node>
<ID>123</ID>
<Name>ABC</Name>
</Node>
<Node>
<ID>124</ID>
<Name>DEF</Name>
</Node>
</Contacts>
Select a single node:
XDocument XMLDoc = XDocument.Load("test.xml");
string id = "123"; // id to be selected
XElement Contact = (from xml2 in XMLDoc.Descendants("Node")
where xml2.Element("ID").Value == id
select xml2).FirstOrDefault();
Console.WriteLine(Contact.ToString());
Delete a single node:
XDocument XMLDoc = XDocument.Load("test.xml");
string id = "123";
var Contact = (from xml2 in XMLDoc.Descendants("Node")
where xml2.Element("ID").Value == id
select xml2).FirstOrDefault();
Contact.Remove();
XMLDoc.Save("test.xml");
Add new node:
XDocument XMLDoc = XDocument.Load("test.xml");
XElement newNode = new XElement("Node",
new XElement("ID", "500"),
new XElement("Name", "Whatever")
);
XMLDoc.Element("Contacts").Add(newNode);
XMLDoc.Save("test.xml");
The .Elements operation returns a LIST of XElements - but what you really want is a SINGLE element. Add this:
XElement Contacts = (from xml2 in XMLDoc.Elements("Contacts").Elements("Node")
where xml2.Element("ID").Value == variable
select xml2).FirstOrDefault();
This way, you tell LINQ to give you the first (or NULL, if none are there) from that LIST of XElements you're selecting.
Marc
Related
I have this XML code:
<AriaGostarInformation>
<MenuInformation>
<MenuNames Name="0" href="default.aspx">home</MenuNames>
<SubMenuNames parentName="1">
fgfgfgfgs
</SubMenuNames>
<SubMenuNames parentName="3">
</SubMenuNames>
</MenuInformation>
<SliderInformation>
<SliderImageAddress>..\..\Img\Hydrangeas.jpg,</SliderImageAddress>
<SliderImageAddress>..\..\Img\Jellyfish.jpg,</SliderImageAddress>
<SliderImageAddress>..\..\Img\Koala.jpg,</SliderImageAddress>
<SliderImageAddress>..\..\Img\Lighthouse.jpg,</SliderImageAddress>
<SliderImageAddress>..\..\Img\Penguins.jpg,</SliderImageAddress>
<SliderImageAddress>..\..\Img\Tulips.jpg,</SliderImageAddress>
</SliderInformation>
<LastProductInformation>
<Product Name="147">
<Subject>
</Subject>
<ProductImageAddress>http://localhost:1209/ckeditor/plugins/imagebrowser/browser/Hydrangeas.jpg</ProductImageAddress>
<ProductDes>
<p><span style="color:#FFA07A;">qwqweqweqe</span>qwe</p>
<p><span style="font-size:11px;">qweqweqw</span>e</p>
</ProductDes>
</Product>
<Product Name="dsa">
<Subject>salm</Subject>
<ProductImageAddress>http://localhost:1209/ckeditor/plugins/imagebrowser/browser/Hydrangeas.jpg</ProductImageAddress>
<ProductDes>
<p>sdADASDASDASDASDASDASD</p>
<p>ASDASDASDADASDASDASDASDA</p>
<p>ASDASDASDASDASDASDASDASDASD</p>
</ProductDes>
</Product>
</LastProductInformation>
</AriaGostarInformation>
I want select last product node in LastProductInformation and get this node's attribute.
My code is:
XmlDocument xdoc = new XmlDocument();
xdoc.Load(AppDomain.CurrentDomain.BaseDirectory + #"\static\css\xml\data.xml");
XmlNode xparent = xdoc.SelectSingleNode("//LastProductInformation");
var b = xparent.SelectSingleNode("/Product[last()]").Attributes["Name"].Value;
but this returns null. What should I do?
Using LINQ to XML
var value = XDocument.Load("path")
.Descendants("Product")
.Last()
.Attribute("Name").Value;
Also you can use XPath with LINQ to XML
var value = XDocument.Load("path")
.XPathSelectElement("//LastProductInformation/Product[last()]")
.Attribute("Name").Value;
Note: Make sure you have a reference to System.Xml.Linq namespace from your project.
You don't have to change to linq.
var b = xparent.SelectSingleNode("//Product")[last()].Attributes["Name"].Value;
The last() works like an index so should be at the end.
I don't how to extract the values from XML document, and am looking for some help as I'm new to C#
I am using XmlDocument and then XmlNodeList for fetching the particular XML document
Here is my code
XmlNodeList XMLList = doc.SelectNodes("/response/result/doc");
And my XML looks like this:
<?xml version="1.0" encoding="UTF-8"?>
<response>
<result>
<doc>
<long name="LoadID">494</long>
<long name="EventID">5557</long>
<str name="XMLData"><TransactionDate>2014-05-28T14:17:31.2186777-06:00</TransactionDate><SubType>tblQM2222Components</SubType><IntegerValue title="ComponentID">11111</IntegerValue></str></doc>
<doc>
<long name="LoadID">774</long>
<long name="EventID">5558</long>
<str name="XMLData"><TransactionDate>2014-05-28T14:17:31.2186777-06:00</TransactionDate><SubType>tblQM2222Components</SubType><IntegerValue title="ComponentID">11111</IntegerValue></str></doc>
</result>
</response>
In this i have to fetch every the XMLData data that is under every doc tag and i have to fetch last doc tag EventID.
var xml = XDocument.Parse(xmlString);
var docs = xml.Root.Elements("doc");
var lastDocEventID = docs.Last()
.Elements("long")
.First(l => (string)l.Attribute("name") == "EventID")
.Value;
Console.WriteLine ("Last doc EventId: " +lastDocEventID);
foreach (var doc in docs)
{
Console.WriteLine (doc.Element("str").Element("TransactionDate").Value);
}
prints:
Last doc EventId: 5558
2014-05-28T14:17:31.2186777-06:00
2014-05-28T14:17:31.2186777-06:00
You can use two XPath expressions to select the nodes you want. To answer each part of your question in turn:
To select all of the XMLData nodes:
XmlNodeList XMLList
= doc.SelectNodes("/response/result/doc/str[#name='XMLData']");
To select the last EventId:
XmlNode lastEventIdNode =
doc.SelectSingleNode("/response/result/doc[position() =
last()]/long[#name='EventID']");
If not all doc nodes are guaranteed to have an event id child node, then you can simply:
XmlNodeList eventIdNodes =
doc.SelectNodes("/response/result/doc[long[#name='EventID']]");
XmlNode lastNode = eventIdNodes[eventIdNodes.Count - 1];
That should give you what you've asked for.
Update;
If you want the XML data inside each strXml element, you can use the InnerXml property:
XmlNodeList xmlList
= doc.SelectNodes("/response/result/doc/str[#name='XMLData']");
foreach(XmlNode xmlStrNode in xmlList)
{
string xmlInner = xmlStrNode.InnerXml;
}
There's one result tag short in your xml.
Try using this. It's cleaner too imho
XmlNodeList docs = doc.SelectSingleNode("response").SelectSingleNode("result").SelectNodes("doc");
Then you can use a combination of SelectSingleNode, InnerText, Value to get the data from each XmlNode in your list.
For example if you want the EventID from the first doc tag:
int eventID = int.Parse(docs[0].SelectSingleNode("long[#name='EventID']").InnerText);
I have xml:
<?xml version="1.0" encoding="UTF-8" standalone="no" ?>
<UpdateMemberHireStatus xmlns="http://tempuri.org/">
<member>
<HireAvailability>
<code>1</code>
<name>פנוי</name>
</HireAvailability>
<HireRejectReason>
<code>2</code>
<name>wow</name>
</HireRejectReason>
<IdNumber>43504349</IdNumber>
<note> </note>
</member>
</UpdateMemberHireStatus>
and I want to use LINQ to access all the nodes in the xml.
Here's what I have tried:
XNamespace ns = "tempuri.org/";
IEnumerable<HireStatus> status = from r in doc.Descendants(ns + "UpdateMemberHireStatus")
.Descendants(ns + "member")
select new HireStatus() { };
return status.ToList();
Use Descendants
var xml = XDocument.Load(XMLStream);
var allEle = xml.Descendants("UpdateMemberHireStatus"); //you can do linq now.
You can use XDocument also in the following way:
string xmlPath = "D://member.xml";
XmlDocument doc = new XmlDocument();
xdoc = XDocument.Load(xmlPath);
doc.LoadXml(xdoc.ToString());
var memberStatus= (from mem in xdoc.Descendants("member")
select mem);
foreach (XElement element in memberStatuses.ToList())
IEnumerable<XNode> nodes = element.Nodes();
var x = XElement.Load(XMLStream);
var all = x.DescendantNodes();
I am trying to add an XML node to multiple parent nodes(which have same name). But it is only adding to the Last node of the XML and not in all.
input XML
<Record>
<Emp>
<ID>12</ID>
<Name>ABC</Name>
</Emp>
<Emp>
<ID>12</ID>
<Name>ABC</Name>
</Emp>
</Record>
I want to add the Location element to every Emp node. My code is as below:
XmlNodeList xNodeList = doc.SelectNodes("/Record/Emp");
XmlElement xNewChild = doc.CreateElement("Location");
xNewChild.InnerText = "USA";
foreach (XmlNode item in xNodeList)
{
item.AppendChild(xNewChild);
}
doc.Save(path);
but I am getting output like this:
<Record>
<Emp>
<ID>12</ID>
<Name>ABC</Name>
</Emp>
<Emp>
<ID>12</ID>
<Name>ABC</Name>
<Location>USA</Location>
</Emp>
</Record>
The Location element has not been added to the first Emp node.
Note: After debugging, I am able to find that the element has been added even for the first Emp node. But, in the saved XML file I am seeing this strange behavior.
Your xNewChild is a single new element. Simply adding it to multiple nodes will only serialize to the last node. A change like this should work:
XmlNodeList xNodeList = doc.SelectNodes("/Record/Emp");
foreach (XmlNode item in xNodeList)
{
XmlElement xNewChild = doc.CreateElement("Location");
xNewChild.InnerText = "USA";
item.AppendChild(xNewChild);
}
doc.Save(path);
I have an xml doc similar to this:
<Root>
<MainItem ID="1">
<SubItem></SubItem>
<SubItem></SubItem>
<SubItem></SubItem>
</MainItem>
<MainItem ID="2">
<SubItem></SubItem>
<SubItem></SubItem>
<SubItem></SubItem>
</MainItem>
...
</Root>
I want to return the whole of the MainItem element based on the value of attribute ID.
So effectively if Attribute ID is equal to 2, then give me that MainItem element back.
I can't work out how to do this with LINQ.
There seems to be a load of information on google, but I just can't quite seem to find what I'm looking for.
Little help ?
TIA
:-)
It could be something like this:
XDocument doc = XDocument.Load("myxmlfile.xml");
XElement mainElement = doc.Element("Root")
.Elements("MainItem")
.First(e => (int)e.Attribute("ID") == 2);
// additional work
How about this:
// load your XML
XDocument doc = XDocument.Load(#"D:\linq.xml");
// find element which has a ID=2 value
XElement mainItem = doc.Descendants("MainItem")
.Where(mi => mi.Attribute("ID").Value == "2")
.FirstOrDefault();
if(mainItem != null)
{
// do whatever you need to do
}
Marc
I changed your XML slightly to have values:
<?xml version="1.0"?>
<Root>
<MainItem ID="1">
<SubItem>value 1</SubItem>
<SubItem>val 2</SubItem>
<SubItem></SubItem>
</MainItem>
<MainItem ID="2">
<SubItem></SubItem>
<SubItem></SubItem>
<SubItem></SubItem>
</MainItem>
</Root>
And with this LINQ:
XDocument xmlDoc = XDocument.Load(#"C:\test.xml");
var result = from mainitem in xmlDoc.Descendants("MainItem")
where mainitem.Attribute("ID").Value == "1"
select mainitem;
foreach (var subitem in result.First().Descendants())
{
Console.WriteLine(subitem.Value);
}
Console.Read();
From here: How to: Filter on an Attribute (XPath-LINQ to XML)
// LINQ to XML query
IEnumerable<XElement> list1 =
from el in items.Descendants("MainItem")
where (string)el.Attribute("ID") == "2"
select el;
// XPath expression
IEnumerable<XElement> list2 = items.XPathSelectElements(".//MainItem[#ID='2']");