I was working on a bunch of XMLs that all share an attribute that contains the string "name" in them. The following code selects the attribute with string "name" in it and assign a new value to it.
public void updateXmlFile(string strFileName)
{
try
{
//Load the Document
XmlDocument doc = new XmlDocument();
doc.Load(strFileName);
//Set the changed Value
string newValue = GetUniqueKey();
//Select all nodes in the XML then choose from them
//the first node that contain string "name" in it
XmlNodeList list = doc.SelectNodes("//#*");
XmlNode filteredNode = list.Cast<XmlNode>()
.First(item => item.Name.ToLower().Contains("name"));
//Assign the newValue to the value of the node
filteredNode.Value = newValue;
doc.Save(strFileName);
}
catch (XmlException xex) { Console.WriteLine(xex); }
}
Now a new XMLs were added that dosen't have the string "name" in them, so instead of modifying the attribute with string "name" in it I decided to simply modify the last attribute no matter what it was (not the first)
Can anybody tell me how to do that?
EDIT
Here is an example of my XML
<?xml version="1.0" encoding="utf-8"?>
<CO_CallSignLists Version="24" ModDttm="2010-09-13T06:45:38.873" ModUser="EUADEV\SARE100" ModuleOwner="EUADEVS06\SS2008" CreateDttm="2009-11-05T10:19:31.583" CreateUser="EUADEV\A003893">
<CoCallSignLists DataclassId="E3FC5E2D-FE84-492D-AD94-3ACCED870714" EntityId="E3FC5E2D-FE84-492D-AD94-3ACCED870714" MissionID="4CF71AB2-0D92-DE11-B5D1-000C46F3773D" BroadcastType="S" DeputyInSpecialList="1" SunSpots="1537634cb70c6d80">
<CoCallSigns EntityId="DEBF1DDB-3C92-DE11-A280-000C46F377C4" CmdID="C45F3EF1-1292-DE11-B5D1-000C46F3773D" ModuleID="6CB497F3-AD63-43F1-ACAE-2C5C3B1D7F61" ListType="HS" Name="Reda Sabassi" Broadcast="INTO" PhysicalAddress="37" IsGS="1" HCId="0" CommonGeoPos="1" GeoLat="0.0000000" GeoLong="0.0000000">
<CoRadios EntityId="E1BF1DDB-3C92-DE11-A280-000C46F377C4" RadioType="HF" />
</CoCallSigns>
</CoCallSignLists>
</CO_CallSignLists>
#Alex: You notice that the "SunSpots" attribute (last attribute in the first child element) is successfully changed. But now when I wanna load the XML back into the DB it gives me an error
Here is the modified code
public void updateXmlFile(string strFileName)
{
try
{
XDocument doc = XDocument.Load(strFileName);
XAttribute l_attr_1 = (doc.Elements().First().Elements().First().Attributes().Last());
l_attr_1.Value = GetUniqueKey();
Console.WriteLine("Name: {0} Value:{1}", l_attr_1.Name, l_attr_1.Value);
doc.Save(strFileName);
}
catch (XmlException xex) { Console.WriteLine(xex); }
}
I was thinking of making an if statment which checks if the XML has an attribute that contains string "name" in it (since most of my XMLs has an attribute that contains name in them) if it does then change the attribute's value if not look for the last attribute and change it.. not the best solution but just throwing it out there
Then definitely use Linq to XML.
Example:
using System.Xml.Linq;
string xml = #"<?xml version=""1.0"" encoding=""utf-8""?>
<Commands Version=""439"" CreateUser=""Reda"">
<CmCommands DataclassId=""57067ca8-ef96-4d2e-a085-6bd7e8b24126"" OrderName = ""Tea"" Remark=""Black"">
<CmExecutions EntityId=""A9A5B0F2-6AB4-4619-9106-B0F85F86EE01"" Lock=""n"" />
</CmCommands>
</Commands>";
XDocument x = XDocument.Parse(xml);
Debug.Print(x.Elements().First().Elements().First().Attributes().Last().Value);
// Commands ^ CmCommands ^ Remark ^
That is, word for word, the last attribute of the first child of the first element.
You can also query for element/attribute names, like:
Debug.Print(x.Descendants(XName.Get("CmCommands", "")).First().Attribute(XName.Get("Remark", "")).Value);
And of course you can use all of the Linq goodness like Where, Select, Any, All etc.
Note: replace XDocument.Parse with XDocument.Load if appropriate etc.
I've not tested this but you should be able to do all of this in the XPath expression. Something like this:
//#*[contains(node-name(.), 'name')][last()]
This will return only the last attribute with the string name anywhere in its name.
If you only want the last attribute, irrespective of it's name, use this:
//#*[last()]
Look at class XmlAttributeCollection. You can get this collection by reading property Attributes of XmlNode. Just get the last by index.
Instead of .First(), use an extension method like this:
public static T LastOrDefault<T>(this IEnumerable<T> list)
{
T val = null;
foreach(T item in list)
{
val = item;
}
return val;
}
Related
Hy at all,
i am new in C# programming so maybe this is a easy question.
I try to read an XML-file with XDocument and write out the local name of a Element as string.
For the output i use the listing window of SiemensNX but every other output window or txt-file is suitable.
Here is the Input-XML:
<?xml version="1.0" encoding="utf-8"?>
<Rootlvl>
<Lvl_1>
<Lvl_2/>
</Lvl_1>
</Rootlvl>
Here is the C# code:
using System.Xml.Linq;
using NXOpen;
namespace XmlElementName
{
class Program
{
private static ListingWindow lw = s.ListingWindow;
public static void Main()
{
string XmlFilePath = #"C:\Users\XXX\Desktop\TestXML.xml"; //XML path
string testnode = "Lvl_2"; //local name of a optional XML element
lw.Open(); //open NX listinwindow for output
//=============LoadXmlFile================
//get main Input
XDocument xml = XDocument.Load(XmlFilePath); //load XmlFile
//====================WriteOutElementName====================
XElement node;
if (testnode == null) //if no optional Element name --> take root element of XML
{
node = xml.Root;
}
else
{
// Find node to passed string "testnode" --> here "Lvl_2"
node = xml.Element(testnode);
}
lw.WriteLine("Test"); //Test if output works --> !yes it works
if(node != null)
{
string output = node.Name.LocalName;
//local name of XElement-variable "node" to string
lw.WriteLine(output); //output the local name of variable "node"
}
else
{
lw.WriteLine("Element with Name = " + testnode + "not found")
}
}
}
}
The Output if variable testnode = "Lvl_2" should be:
Test
Lvl_2
The Output if variable testnode = null schould be:
Test
Rootlvl
The VS Debugger show me that
node = xml.Element(testnode); //testnode = Lvl_2
can't find an element in the XML with the the name "Lvl_2". So it set "node" to "Null" and throw the following exeption:
"System.NullReferenceException: Object reference not set to an instance of an object."
But i know that "Lvl_2" is a subelement of the XML. What can i do to found this element "Lvl_2" in the XML?
What should i change in this line
node = xml.Element(testnode)
to find the element by name?
Thanks for your help guys.
According to MSDN:
Method XDocument.Element(XName) gets the first (in document order)
child element with the specified XName.
So, in your case,
node = xml.Element(testnode)
returns null if testnode = "Lvl_2", because Lvl_2 is not a child element of the xml document (only the root node Rootlvl is considered as a child element is this context).
Try using Descendants method instead:
node = xml.Descendants(testnode).FirstOrDefault();
If you put a testnode that is not present in the xml then node is null and it causes an exception, do the check before printing
if (node!=null){
string output = node.Name.LocalName;
//local name of XElement-variable "node" to string
lw.WriteLine(output); //output the local name of variable "node"
}
Thanks #jdweng,
i take the following changes. Now it works.
using system.linq;
and replace
node.xml.Element(testnode);
with
node = xml.Descendents(testnode).FirstOrDefault();
In C#, I am trying to change an option of a feature in an XML file which presents a Print Ticket and loaded as an XElement by the following code:
XElement ticketRootXElement = null;
using (Stream ticketReadStream = displayedPrintTicket.GetReadStream())
{
ticketRootXElement = XElement.Load(ticketReadStream);
}
The partial XML is something like following:
<?xml version="1.0"?>
<psf:Feature xmlns:psf="http://schemas.microsoft.com/windows/2003/08/printing/printschemaframework" name="psk:PageMediaSize">
<psf:Option name="psk:ISOA4">
<psf:ScoredProperty name="psk:MediaSizeWidth">
<psf:Value xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="xsd:integer">210000</psf:Value>
</psf:ScoredProperty>
<psf:ScoredProperty name="psk:MediaSizeHeight">
<psf:Value xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="xsd:integer">297000</psf:Value>
</psf:ScoredProperty>
</psf:Option>
</psf:Feature>
How can I access the "Option" of a specific "Feature" and change it to something like <psf:Option name="psk:ISOA3">?
I tried the following code, but it fails.
foreach (XAttribute xAttr in ticketRootXElement.Descendants(xns_psf + "Feature").Attributes())
{
if (xAttr.Value.Equals("psk:PageMediaSize"))
{
foreach(XAttribute xSubAttr in ticketRootXElement.Element("PageMediaSize").Descendants(xns_psf + "Option").Attributes())
{
if (xAttr.NextAttribute.Name.LocalName.Equals("name"))
{
xAttr.NextAttribute.SetValue("psk:ISO" + cmb_PaperSize.SelectedValue.ToString());
}
}
}
}
You can can modify the option value of your selected feature as as follows:
var featureName = "psk:PageMediaSize";
var newOptionValue = "psk:ISOA3"; // Your modified value here
XNamespace xns_psf = #"http://schemas.microsoft.com/windows/2003/08/printing/printschemaframework";
var query = from f in ticketRootXElement.DescendantsAndSelf(xns_psf + "Feature")
where (string)f.Attribute("name") == featureName
select f;
foreach (var f in query)
{
// TODO: handle the situation were a child <psf:Option> element is missing.
f.Element(xns_psf + "Option").SetAttributeValue("name", newOptionValue);
}
Notes:
XElement.Attribute(XName) can be used to look up an attribute by name, and XElement.SetAttributeValue(XName, Object) can be used to set or add an attribute value by name.
Casting an XAttribute to a string returns the value of the attribute, or null if the attribute was missing, and so is convenient to use when filtering by attribute value in a where statement.
If the selected <psf:Feature> element does not have a child <psf:Option> element, the above code will throw an exception. You will need to check your XML schema to determine whether this is possible, and if so, how to handle it.
Demo fiddle here.
Actually I did it using the following code. But "bdc" solution (above answer) sounds much better:
var element = ticketRootXElement.Descendants(xns_psf + "Feature")
.Where(arg => arg.Attribute("name").Value == "psk:PageMediaSize")
.Single();
var subelement = element.Descendants(xns_psf + "Option")
.Single();
subelement.FirstAttribute.SetValue("psk:ISOA3");
Load function is already defined in xmlData class
public class XmlData
{
public void Load(XElement xDoc)
{
var id = xDoc.XPathSelectElements("//ID");
var listIds = xDoc.XPathSelectElements("/Lists//List/ListIDS/ListIDS");
}
}
I'm just calling the Load function from my end.
XmlData aXmlData = new XmlData();
string input, stringXML = "";
TextReader aTextReader = new StreamReader("D:\\test.xml");
while ((input = aTextReader.ReadLine()) != null)
{
stringXML += input;
}
XElement Content = XElement.Parse(stringXML);
aXmlData.Load(Content);
in load function,im getting both id and and listIds as null.
My test.xml contains
<SEARCH>
<ID>11242</ID>
<Lists>
<List CURRENT="true" AGGREGATEDCHANGED="false">
<ListIDS>
<ListID>100567</ListID>
<ListID>100564</ListID>
<ListID>100025</ListID>
<ListID>2</ListID>
<ListID>1</ListID>
</ListIDS>
</List>
</Lists>
</SEARCH>
EDIT: Your sample XML doesn't have an id element in the namespace with the nss alias. It would be <nss:id> in that case, or there'd be a default namespace set up. I've assumed for this answer that in reality the element you're looking for is in the namespace.
Your query is trying to find an element called id at the root level. To find all id elements, you need:
var tempId = xDoc.XPathSelectElements("//nss:id", ns);
... although personally I'd use:
XDocument doc = XDocument.Parse(...);
XNamespace nss = "http://schemas.microsoft.com/SQLServer/reporting/reportdesigner";
// Or use FirstOrDefault(), or whatever...
XElement idElement = doc.Descendants(nss + "id").Single();
(I prefer using the query methods on LINQ to XML types instead of XPath... I find it easier to avoid silly syntax errors etc.)
Your sample code is also unclear as you're using xDoc which hasn't been declared... it helps to write complete examples, ideally including everything required to compile and run as a console app.
I am looking at the question 3 hours after it was submitted and 41 minutes after it was (last) edited.
There are no namespaces defined in the provided XML document.
var listIds = xDoc.XPathSelectElements("/Lists//List/ListIDS/ListIDS");
This XPath expression obviously doesn't select any node from the provided XML document, because the XML document doesn't have a top element named Lists (the name of the actual top element is SEARCH)
var id = xDoc.XPathSelectElements("//ID");
in load function,im getting both id and and listIds as null.
This statement is false, because //ID selects the only element named ID in the provided XML document, thus the value of the C# variable id is non-null. Probably you didn't test thoroughly after editing the XML document.
Most probably the original ID element belonged to some namespace. But now it is in "no namespace" and the XPath expression above does select it.
string xmldocument = "<response xmlns:nss=\"http://schemas.microsoft.com/SQLServer/reporting/reportdesigner\"><action>test</action><id>1</id></response>";
XElement Content = XElement.Parse(xmldocument);
XPathNavigator navigator = Content.CreateNavigator();
XmlNamespaceManager ns = new XmlNamespaceManager(navigator.NameTable);
ns.AddNamespace("nss", "http://schemas.microsoft.com/SQLServer/reporting/reportdesigner");
var tempId = navigator.SelectSingleNode("/id");
The reason for the null value or system returned value is due to the following
var id = xDoc.XPathSelectElements("//ID");
XpathSElectElements is System.xml.linq.XElment which is linq queried date. It cannot be directly outputed as such.
To Get individual first match element
use XPathSelectElement("//ID");
You can check the number of occurrences using XPathSelectElements as
var count=xDoc.XPathSelectElements("//ID").count();
you can also query the linq statement as order by using specific conditions
Inorder to get node value from a list u can use this
foreach (XmlNode xNode in xDoc.SelectNodes("//ListIDS/ListID"))
{
Console.WriteLine(xNode.InnerText);
}
For Second list you havnt got the value since, the XPath for list items is not correct
I have a combobox and when users select them xml is parsed.
if i choose item1, i need to select this "C:\folder1" as a path.
item 2: "C:\folder2"
item 3: "C:\folder3"
my XML file:
<?xml version="1.0"?>
<main>
<target>C:\folder1</target>
<target>C:\folder2</target>
<target>C:\folder3</target>
</main>
I am using Xdocument to do the parsing:
private void pathselection()
{
XDocument pathdoc = XDocument.Load(#"C:\GUI\path.xml");
var abc = from target in pathdoc.Descendants("target")
...
...
}
now i am stuck over here. should i include if statements inside pathselection()? and how do i parse the path?
EDIT1:
Btw, i would like to store these path as strings
string selectedpath1 = "";
Given that the selectable items in the ComboBox match the items in the XML, you can get the target elements by index:
private void pathselection()
{
XDocument pathdoc = XDocument.Load(#"C:\GUI\path.xml");
var abc = pathdoc.Descendants("target")
.Where((e, i) => i == MyComboBox.SelectedIndex)
.Single();
}
You might want to handle things like when the indexes don't match and you might want to use SingleOrDefault or FirstOrDefault to deal with that.
I decided to try out the tutorial on this website
http://www.csharphelp.com/2006/05/creating-a-xml-document-with-c/
Here's my code, which is more or less the same but a bit easier to read
using System;
using System.Xml;
public class Mainclass
{
public static void Main()
{
XmlDocument XmlDoc = new XmlDocument();
XmlDocument xmldoc;
XmlNode node1;
node1 = XmlDoc.CreateNode(XmlNodeType.XmlDeclaration, "", "");
XmlDoc.AppendChild(node1);
XmlElement element1;
element1 = XmlDoc.CreateElement("", "ROOT", "");
XmlText text1;
text1 = XmlDoc.CreateTextNode("this is the text of the root element");
element1.AppendChild(text1);
// appends the text specified above to the element1
XmlDoc.AppendChild(element1);
// another element
XmlElement element2;
element2 = XmlDoc.CreateElement("", "AnotherElement", "");
XmlText text2;
text2 = XmlDoc.CreateTextNode("This is the text of this element");
element2.AppendChild(text2);
XmlDoc.ChildNodes.Item(1).AppendChild(element2);
}
}
So far, I'm liking XmlDocument, but I can't figure out how this line works
XmlDoc.ChildNodes.Item(1).AppendChild(element2);
Specifically, the Item() part of it
according to MSDN...
//
// Summary:
// Retrieves a node at the given index.
//
// Parameters:
// index:
// Zero-based index into the list of nodes.
//
// Returns:
// The System.Xml.XmlNode in the collection. If index is greater than or equal
// to the number of nodes in the list, this returns null.
However, I'm still not really sure what "index" refers to, or what Item() does. Does it move down the tree or down a branch?
Also, when I was looking at it, I thought it would end up like this
what I thought would happen:
<?xml version="1.0"?>
<ROOT>this is the text of the root element</ROOT>
<AnotherElement>This is the text of this element</AnotherElement>
but it ended up like this
Actual output
<?xml version="1.0"?>
<ROOT>this is the text of the root element
<AnotherElement>This is the text of this element</AnotherElement>
</ROOT>
(formatting added)
The ChildNodes property returns the XmlNodeList of immediate children of what you call it on. Item then finds the nth member of that list. It won't recurse into grand-children etc. In particular, I believe in this case Item(0) would return the XML declaration, and Item(1) returns the root element. A nicer way of expressing "get to the root element" would be to use XmlDocument.DocumentElement.
Note that your "expected" output wouldn't even be valid XML - an XML document can only have one root element.
To be honest, this isn't a terribly nice use of it - and in particular I would recommend using LINQ to XML rather than XmlDocument if you possibly can. It's not particularly clear what you're trying to achieve with the code you've given, but it would almost certainly be much simpler in LINQ to XML.