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C# WPF Unable to write to XML file

I am new to WPF and am attempting to write a child node to an XML file. Here is the file...
<?xml version="1.0" encoding="utf-8"?>
<Sequences>
<LastSavedSequence name="Last Saved Sequence">
<Test name="Measure Battery Current(Stim)" testNumber="5" Vbat="3.7" Frequency="20" PulseWidth="500" Amplitude="1" Resistance="1600" Anode="1" Cathode="2" ActiveDischarge=""/>
<Test name="Measure Batther Current(No Stim)" testNumber="6" Vbat="2.9" Frequency="20" PulseWidth="500" Amplitude="1" Resistance="1600" Anode="1" Cathode="2" ActiveDischarge=""/>
</LastSavedSequence>
<ScottTestSequence name="Scott Test Sequence">
<Test name="VMO Status" testNumber="4" Vbat="3.7" Frequency="20" PulseWidth="1000" Amplitude="6" Resistance="3000" Anode="1" Cathode="2" ActiveDischarge=""/>
<Test name="Measure Battery Current(Stim)" testNumber="5" Vbat="3.7" Frequency="20" PulseWidth="500" Amplitude="1" Resistance="1600" Anode="1" Cathode="2" ActiveDischarge=""/>
<Test name="Measure Batther Current(No Stim)" testNumber="6" Vbat="2.9" Frequency="20" PulseWidth="500" Amplitude="1" Resistance="1600" Anode="1" Cathode="2" ActiveDischarge=""/>
</ScottTestSequence>
</Sequences>
I am attempting to create an XML child block to go within . I used stringBuilder and then am trying to do an attach child and then a .save. XMLData2 is a global list and contains a the child elements that I get in the for each. Here is my code...
public static List<System.Xml.XmlNode> xmlData2 = new List<System.Xml.XmlNode>();
XmlDocument xmlFromOutSideSequenceFile = new XmlDocument();
xmlFromOutSideSequenceFile.Load("c:\\Users/StarkS02/Documents/SavedSequenceFile.xml");
StringBuilder exampleNode = new StringBuilder();
exampleNode.Append("<");
exampleNode.Append(tbSequenceName.Text.ToString().Replace(" ", ""));
exampleNode.Append(" name=");
exampleNode.Append("'");
exampleNode.Append(tbSequenceName.Text);
exampleNode.Append("'");
exampleNode.Append(">");
foreach (XmlNode node in xmlData2)
{
XmlElement child = xmlFromOutSideSequenceFile.CreateElement(string.Empty, node.OuterXml, string.Empty);
exampleNode.Append("</");
exampleNode.Append(tbSequenceName.Text.ToString().Replace(" ", ""));
exampleNode.Append(">");
xmlFromOutSideSequenceFile.AppendChild(exampleNode);
xmlFromOutSideSequenceFile.Save("c:\\Users/StarkS02/Documents/SavedSequenceFile.xml");
I get a compiler error on the .appendChild statement that I cannot convert a stringBuilder to an XML node. This makes sense but I'm not sure how to fix it. Any ideas?

You can create an XML fragment and append to the document.
var xmlFromOutSideSequenceFile = new XmlDocument();
xmlFromOutSideSequenceFile.Load("c:\\Users/StarkS02/Documents/SavedSequenceFile.xml");
See here for more on DocumentFragment
https://msdn.microsoft.com/en-us/library/system.xml.xmldocument.createdocumentfragment(v=vs.110).aspx
var fragment = xmlFromOutSideSequenceFile.CreateDocumentFragment();
fragment.InnerXml = #"<somexml></somexml>";
xmlFromOutSideSequenceFile.DocumentElement.FirstChild.AppendChild(fragment);
See here for more on XMLNode
https://msdn.microsoft.com/en-us/library/system.xml.xmlnode(v=vs.110).aspx
Decide where you want to put it.
.FirstChild
.LastChild
.NextSibling
.ParentNode
.PreviousSibling
Hope this helps! Cheers!

xmlNode not deleting

im unable to delete an xml node from a xml file. Im unable to figure out what is the issue in my code. I have attached my code
class Program
{
static void Main(string[] args)
{
XmlDocument xDoc=new XmlDocument();
xDoc.Load(#"C:\Users\MyUser\Desktop\Family.xml");
//try 1
XmlNode firstNode=xDoc.SelectSingleNode("Apartments/Family[Father='Father1']");
xDoc.LastChild.RemoveChild(firstNode);
xDoc.RemoveAll();
//Try2
XmlNodeList nodeColl = xDoc.GetElementsByTagName("Apartments/Family");
foreach (XmlNode xNode in nodeColl)
{
if (xNode["Father"].InnerText == "Father1")
{
xNode.ParentNode.RemoveChild(xNode);
}
}
// firstNode.ParentNode.RemoveChild(firstNode);
}
}
the Xml document format is
<?xml version="1.0"?>
<Apartments>
<Family>
<Father>Father1</Father>
<Mother>Mother1</Mother>
<Daughter>Daughter1</Daughter>
<Son>Son1</Son>
</Family>
<Family>
<Father>Father2</Father>
<Mother>Mother2</Mother>
<Daughter>Daughter2</Daughter>
<Son>Son2</Son>
</Family>
<Family>
<Father>Father3</Father>
<Mother>Mother3</Mother>
<Daughter>Daughter3</Daughter>
<Son>Son3</Son>
</Family>
<Family>
<Father>Father4</Father>
<Mother>Mother4</Mother>
<Daughter>Daughter4</Daughter>
<Son>Son4</Son>
</Family>
</Apartments>
Please let me know where im wrong.

After the modifications you need to save the changes to file.
XmlDocument xDoc=new XmlDocument();
xDoc.Load(#"C:\Users\MyUser\Desktop\Family.xml");
XmlNodeList nodeColl = xDoc.GetElementsByTagName("Apartments/Family");
foreach (XmlNode xNode in nodeColl)
{
if (xNode["Father"].InnerText == "Father1")
{
xNode.ParentNode.RemoveChild(xNode);
}
}
// save the changes back to file
xDoc.Save(#"C:\Users\MyUser\Desktop\Family.xml");

Add a key,value node to xml file under specific xPath in C#

I have an xml File
<configuration>
<MetisLinks>
<add key="MetisInternal" value="https://xyz.abc.com/" />
<add key="Hermes" value="https://hermes.abc.com/" />
<add key="umar" value="https://umar.abc.com/" />
</MetisLinks>
</configuration>
I need to add custom key and value in this MetisLink node using C#. Also if it already exists than overwrite.I searched for different solution but the exact was not on internet.
Thanks in advance!

This code should work for you:
string keyToAdd = "testKey";
string valueToAdd = "http://test.com";
XmlDocument doc = new XmlDocument();
doc.Load(#"D:\build.xml");
XmlNode root = doc.DocumentElement;
XmlElement existingMatchingElement = (XmlElement)root.SelectSingleNode(string.Format("//MetisLinks/add[#key='{0}']", keyToAdd));
if (existingMatchingElement != null)
{
existingMatchingElement.SetAttribute("value", valueToAdd);
}
else
{
XmlNode myNode = root.SelectSingleNode("MetisLinks");
var nodeToAdd = doc.CreateElement("add");
nodeToAdd.SetAttribute("key", keyToAdd);
nodeToAdd.SetAttribute("value", valueToAdd);
myNode.AppendChild(nodeToAdd);
}
doc.Save(#"D:\build.xml");
I created a file at D:\build.xml and copied your xml there, you could place your file containing that xml anywhere and just use that path in the code

Exception while reading XML - "Namespace Manager or XsltContext needed"

My xml is as below
<?xml version="1.0" encoding="ISO-8859-1"?>
<?xml-stylesheet type="text/xsl" href="../../config/janes-deliver.xsl"?>
<!DOCTYPE janes:record SYSTEM "../../config/janesml-delivery-norm-2.1.dtd">
<janes:record xmlns:janes="http://dtd.janes.com/2002/Content/" id="j1891356689831320" pubabbrev="JIQ" sysId="JIQ0105" urname="record">
<janes:metadata xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="j1891356689831320" urname="metadata" xlink:type="simple">
<dc:rights xmlns:dc="http://purl.org/dc/elements/1.1/">Copyright © IHS Global Limited, 2014</dc:rights>
<dc:date xmlns:dc="http://purl.org/dc/elements/1.1/" qualifier="pubDate">30000101</dc:date>
<dc:date xmlns:dc="http://purl.org/dc/elements/1.1/" qualifier="postDate">20140822</dc:date>
<janes:title urname="title">IHS Jane's Navigating the Emerging Markets</janes:title>
<janes:shortTitle urname="shortTitle">Canada</janes:shortTitle>
<janes:sect1 id="j18967561358768718373" urname="sect1">
<janes:para id="j18967561358768718388" urname="para"><janes:link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="jiq0105_a.pdf" qualifier="pdf" urname="link" xlink:type="simple"><janes:linkText urname="linkText">Please click here for the full PDF report.</janes:linkText></janes:link></janes:para>
</janes:sect1>
<janes:sect1 id="j26330201380885096083" updated="y" urname="sect1">
<janes:title urname="title">Military inventories</janes:title>
.......................
I need to retrieve the contents of the tag
I have written a code like below
XmlDocument doc = new XmlDocument();
doc.Load(filepath);
foreach (XmlNode node in doc.SelectNodes("janes:link"))
{
string name = node.Name;
string value = node.InnerText;
// ...
}
I am getting the error "Namespace Manager or XsltContext needed. This query has a prefix, variable, or user-defined function."
Can Some one help ?

Try this:
XmlDocument doc = new XmlDocument();
doc.Load(filepath);
var nsmgr = new XmlNamespaceManager(doc.NameTable);
nsmgr.AddNamespace("janes", "http://dtd.janes.com/2002/Content/");
foreach (XmlNode node in doc.SelectNodes(#"//janes:link", nsmgr))
{
//...
}
This answers explains why XmlNamespaceManager is needed.

how to check if xml document has a certain list of attributes?

i am experimenting with C# and xml, i am trying to read a XML file i want to validate if "NumberOfDays" , "NumberOfBooks", "NumberOfExam", "CurrentDate" are existing, if missing. i want to add them with there values.
i have the following xmldocument :
<?xml version="1.0" encoding="utf-8" ?>
<MySample>
<Content>
<add key="NumberOfDays" value="31" />
<add key="NumberOfBooks" value="20" />
<add key="NumberOfExam" value="6" />
<add key="CurrentDate" value="15 - Jul - 2011" />
</Content>
</MySample>
i am writing a sample application in c# using
--------Edit--------
thank you AresAvatar for your responce.
but if the value exists i would like to update its value i.e. if let's say
<add key="NumberOfExam" value="" />
i want to change the value to 6

You can get a list of which nodes exist like this:
// Get a list of which nodes exist
XmlDocument doc = new XmlDocument();
doc.LoadXml(myXml);
List<string> existingNodes = new List<string>();
XmlNodeList bookNodes = doc.SelectNodes("/MySample/Content/add");
foreach (XmlNode nextNode in bookNodes)
{
foreach (XmlAttribute nextAttr in nextNode.Attributes)
existingNodes.Add(nextAttr.InnerText);
}
You can add missing nodes like this:
// Add nodes
XmlNode addRoot = doc.SelectSingleNode("/MySample/Content");
XmlElement addme = doc.CreateElement("add");
addme.SetAttribute("NumberOfDays", "31");
addRoot.AppendChild(addme);
You can set the value of existing nodes like this:
// Update a node
foreach (XmlNode nextNode in bookNodes)
{
foreach (XmlAttribute nextAttr in nextNode.Attributes)
{
switch (nextAttr.Name)
{
case "NumberOfDays":
((XmlElement)nextNode).SetAttribute("value", "31");
break;
// etc.
}
}
}

First of all, if you have control over the generated XML (if you make it yourself), avoid using this schema:
<?xml version="1.0" encoding="utf-8" ?>
<MySample>
<Content>
<add key="NumberOfDays" value="31" />
<add key="NumberOfBooks" value="20" />
<add key="NumberOfExam" value="6" />
<add key="CurrentDate" value="15 - Jul - 2011" />
</Content>
</MySample>
It's much easier to use with that schema:
<?xml version="1.0" encoding="utf-8" ?>
<MySample>
<Content>
<Adds>
<NumberOfDays>31<NumberOfDays/>
<NumberOfBooks>20<NumberOfBooks/>
<NumberOfExam>6<NumberOfExam/>
<CurrentDate>5 - Jul - 2011<CurrentDate/>
</Adds>
</Content>
</MySample>
And then:
XmlDocument doc = new XmlDocument();
doc.Load("YourXmlPath");
XmlNode firstNode = doc["MySample"];
if(firstNode != null)
{
XmlNode secondNode = firstNode["Content"];
if(secondNode != null)
{
XmlNode thirdNode = secondNode["Adds"];
if(thirdNode != null)
{
if(thirdNode["NumberOfDays"] == null) //The "NumberOfDays" node does not exist, we create it.
{
XmlElement newElement = doc.CreateElement("NumberOfDays");
newElement.InnerXml = 31;
thirdNode.AppendChild(newElement);
}
//Do the same for the other nodes...
}
}
}
doc.Save("YourXmlPath");
Just remember to check for null on every node, or put the whole block into a try/catch.
And to save the XML once you did your changes.
XmlDocument.Load() function loads the XML in memory, so you can check for any node without making "blind loops".