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Xml file with C# can't get the value

Here is my xml file
<?xml version="1.0" encoding="ASCII"?>
<Vitals>
<Vendor>General Electric Healthcare</Vendor>
<Model>Pro/Procare</Model>
<Result name="Mean_arterial_pressure">
<Value>86</Value>
<Units name="mmHg"></Units>
<Time_stamp year="2008" month="11" day="18" hour="12" minute="33" second="14"></Time_stamp>
</Result>
<Result name="Systolic_blood_pressure">
<Value>130</Value>
<Units name="mmHg"></Units>
<Time_stamp year="2008" month="11" day="18" hour="12" minute="33" second="14"></Time_stamp>
</Result>
<Result name="Diastolic_blood_pressure">
<Value>67</Value>
<Units name="mmHg"></Units>
<Time_stamp year="2008" month="11" day="18" hour="12" minute="33" second="14"></Time_stamp>
</Result>
<Result name="Pulse">
<Value>73</Value>
<Units name="BPM"></Units>
<Method>blood_pressure</Method>
<Time_stamp year="2008" month="11" day="18" hour="12" minute="33" second="14"></Time_stamp>
</Result>
</Vitals>
and Here is my sourcecode, I having the issue how to get the result name and the value?
private void btnReadXml_Click(object sender, EventArgs e)
{
Hashtable h = new Hashtable();
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load("C:\\dinamap.xml");
XmlNodeList doc_results = xmlDoc.GetElementsByTagName("Vitals/Vendor/Model/Result[#name='Systolic_blood_pressure']");
foreach (XmlNode pnode in doc_results)
{
foreach (XmlNode cnode in pnode.ChildNodes)
{
if (cnode.Name == "Value")
{
h.Add(pnode.Attributes["name"].InnerText + cnode.Name, cnode.Attributes["name"].InnerText);
}
else
{
h.Add(pnode.Attributes["name"].InnerText + "_" + cnode.Name, cnode.InnerText);
}
}
}
}
May I know what wrong of my code? always can't get the value.
I need to get the value from xml file.

On line 5, your xPath specify Model is a child of Vendor while Vendor contains only a string (<Vendor>General Electric Healthcare</Vendor>).
Moreover, to navigate with xPath i advice you to use SelectNodes function.
Try this instead :
XmlNodeList doc_results = xmlDoc.SelectNodes("/Vitals/Model/Result[#name='Systolic_blood_pressure']");

It'd be easier if you used LINQ to XML for this.
var doc = XDocument.Load("path/to/xml");
var results =
from result in doc.Descendants("Result")
select new
{
Name = (string) result.Attribute("name"),
Value = (string) result.Element("Value"),
Units = (string) result.Element("Units").Attribute("name")
};
You could then filter by Name if you needed:
var sysBp = results.Single(x => x.Name == "Systolic_blood_pressure");
See this fiddle for a working demo.

You're currently trying to retrieve the "name" attribute of the child node, which it does not actually have in the case of your value node. If you use cnode.Value you can get the contents of a text note.
Also, Result is not a child of Model, which is not a child of Vendor. You'll either want to properly make them children or change the path you're setting for doc_results

private void btnReadXml_Click(object sender, EventArgs e)
{
var doc = XDocument.Load("C:\\dinamap.xml");
var results = from result in doc.Descendants("Result")
select new
{
Name = (string)result.Attribute("name"),
Value = (string)result.Element("Value"),
Units = (string)result.Element("Units").Attribute("name")
};
foreach (var result in results)
{
MessageBox.Show("{result.Name}: {result.Value} {result.Units}");
}
}

Writing data to existing Xml

I am developing a universal windows app on windows 10 with Visual Studio 2015 and have a pretty large Xml structured like this:
<header id = "1">
<title>
some text
</title>
<question>
a question
</question>
<user_input>
<input1>
</input1>
<input2>
</input2>
</user_input>
</header>
<header id = "2">
<title>
some text
</title>
<question>
a question
</question>
<user_input>
<input1>
</input1>
<input2>
</input2>
</user_input>
</header>
...
This is repeating many times. There are parts that should never be changed (e.g. title, question). Now i want to write new elements into "ui", so it can be read again and shows the new content in texbox.
I use a FileStream and XmlDocument and XmlNodeList to read the Xml and show the content on textblocks:
path = "test.xml";
FileStream stream = new Filestream(path, FileMode.Open, FileAcces.Read);
XmlDocument xdoc = new XmlDocument();
xdoc.Load(reader);
XmlNodeList node = xdoc.GetElementsByTagName("header");
textblock1.Text = node[0].Attributes["id"].Value;
textblock2.Text = node[i].ChildNode[1].InnerText;
....
I tried this to write into the Xml:
XDocument xdoc = XDocument.Load(path);
XElement ele = xdoc.Element("header");
ele.Add(new XElement("user_input",
new XElement("input1", newtext)));
xdoc.Save(path); <---- at this point there is an error
"Argument 1: cannot convert from 'string' to 'System.IO.Stream'"
My question is: how can i write the user input (some string) to the place I want it to be? The first input shall be written into header with id = 1 into user_input, the second into header id = "2" and so on. I already tried to load the xml with XDocument and write a new element with XElement, but it work at all.Is there something wrong with my xml? Or is it the function? Thank you in advance.

Firstly, the xml file cannot contain same roots, here you have two headers nodes but don't see a root node. So I add a root node for testing your xml file as follows
<?xml version="1.0" encoding="utf-8"?>
<Topics>
<header id = "1">
...
</header>
</Topics>
Secondly, this error
"Argument 1: cannot convert from 'string' to 'System.IO.Stream'"
xdoc.save(string) is not available in uwp, details you can see the version information of XDocument.Save method.
Thirdly, for this question
how can i write the user input (some string) to the place I want it to be?
we can insert value to special element by xpath or GetElementsByTagName method. In uwp, I recommend you use Windows.Data.Xml.Dom namespace instead of System.xml.Ling.
Here I wrote a demo for insert value to special place . And upload the demo to GitHub, you can download CXml for testing.
Mainly Code
private async void BtnXmlWrite_Click(object sender, RoutedEventArgs e)
{
String input1value = TxtInput.Text;
if (null != input1value && "" != input1value)
{
var value = doc.CreateTextNode(input1value);
//find input1 tag in header where id=1
var xpath = "//header[#id='1']/user_input/input1";
var input1nodes = doc.SelectNodes(xpath);
for (uint index = 0; index < input1nodes.Length; index++)
{
input1nodes.Item(index).AppendChild(value);
}
RichEditBoxSetMsg(ShowXMLResult, doc.GetXml(), true);
}
else
{
await new Windows.UI.Popups.MessageDialog("Please type in content in the box firstly.").ShowAsync();
}
}
More details you can reference XML dom Sample, XML and XPath.

Search through XML and grab another Node

<?xml version="1.0" encoding="UTF-8"?>
<Envelope xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<Message>
<MessageID>1</MessageID>
<Product>
<SKU>33333-01</SKU>
</Product>
</Message>
</Envelope>
I've tried googling but whether I'm just not providing the correct search criteria I don't know.
I want to be able to search the XML file based on the MessageID and then grab the SKU.
I then want to search another XML file based on the SKU and remove that message completely.
<?xml version="1.0" encoding="UTF-8"?>
<Envelope xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<Message>
<MessageID>1</MessageID>
<Inventory>
<SKU>33333-01</SKU>
<Quantity>1</Quantity>
</Inventory>
</Message>
<Message>
<MessageID>2</MessageID>
<Inventory>
<SKU>22222-01</SKU>
<Quantity>1</Quantity>
</Inventory>
</Message>
</Envelope>
Meaning the XML above becomes:
<?xml version="1.0" encoding="UTF-8"?>
<Envelope xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<Message>
<MessageID>2</MessageID>
<Inventory>
<SKU>22222-01</SKU>
<Quantity>1</Quantity>
</Inventory>
</Message>
</Envelope>
To confirm I cannot confirm that the MessageID will be the same over different XML files.
Thanks in advance for any help.
My questions:
How do I search through XML files?
How do I then grab another Nodes details
Can I remove a complete from an XML file based on a search?

You can use XmlDocument to load your XML document. Then, you can use XPath for searching any nodes.
XmlDocument document = new XmlDocument();
document.Load("C:\fileOnTheDisk.xml");
// or
document.LoadXml("<a>someXmlString</a>");
// Returns single element or null if not found
var singleNode = document.SelectSingleNode("Envelope/Message[MessageID = '1']");
// Returns a NodeList
var nodesList = document.SelectNodes("Envelope/Message[MessageID = '1']");
Read more about XPath at w3schools.com.
Here is a good XPath Tester.
For example, you can use the following XPath to find nodes in your document by ID:
XmlDocument document = new XmlDocument();
document.Load("C:\doc.xml");
var node = document.SelectSingleNode("Envelope/Message[MessageID = '1']");
var sku = node.SelectSingleNode("Inventory/SKU").InnerText;
Console.WriteLine("{0} node has SKU = {1}", 1, sku);
Or you can output all SKUs:
foreach (XmlNode node in document.SelectNodes("Envelope/Message"))
{
Console.WriteLine("{0} node has SKU = {1}",
node.SelectSingleNode("MessageID").InnerText,
node.SelectSingleNode("Inventory/SKU").InnerText);
}
It will produce:
1 node has SKU = 33333-01
2 node has SKU = 22222-01
Note that there are possible NullReferenceExceptions if nodes are not present.
You can simply remove it using RemoveChild() method of its parent.
XmlDocument document = new XmlDocument();
document.Load("C:\doc.xml");
var node = document.SelectSingleNode("Envelope/Message[MessageID = '1']");
node.ParentNode.RemoveChild(node);
document.Save("C:\docNew.xml"); // will be without Message 1

You can use Linq to XML to do this:
var doc= XDocument.Load("input.xml");//path of your xml file in which you want to search based on message id.
var searchNode= doc.Descendants("MessageID").FirstOrDefault(d => d.Value == "1");// It will search message node where its value is 1 and get first of it
if(searchNode!=null)
{
var SKU=searchNode.Parent.Descendants("SKU").FirstOrDefault();
if(SKU!=null)
{
var searchDoc=XDocument.Load("search.xml");//path of xml file where you want to search based on SKU value.
var nodes =searchDoc.Descendants("SKU").Where(d=>d.Value==SKU.Value).Select(d=>d.Parent.Parent).ToList();
nodes.ForEach(node=>node.Remove());
searchDoc.Save("output.xml");//path of output file
}
}

I'd recommend you did this using LINQ to XML - it's much nicer to work with than the old XmlDocument API.
For all the examples, you can parse your XML string xml to an XDocument like so:
var doc = XDocument.Parse(xml);
1. How do I search through XML files?
You can get the SKU for a specific message ID by querying your document:
var sku = (string)doc.Descendants("Message")
.Where(e => (int)e.Element("MessageID") == 1)
.SelectMany(e => e.Descendants("SKU"))
.Single();
2. How do I then grab another Nodes details?
You can get the Message element with a specified SKU using a another query:
var message = doc.Descendants("SKU")
.Where(sku => (string)sku == "33333-01")
.SelectMany(e => e.Ancestors("Message"))
.Single();
3. Can I remove a complete element from an XML file based on a search?
Using your result from step 2, you can simple call Remove:
message.Remove();
Alternatively, you can combine the query from step 2 and simply execute a command to remove any messages that have a specific SKU:
doc.Descendants("SKU")
.Where(sku => (string)sku == "33333-01")
.SelectMany(e => e.Ancestors("Message"))
.Remove();

I tried to answer all your questions:
using System.Xml.XPath;
using System.Xml.Linq;
XDocument xdoc1 = XDocument.Load("xml1.xml");
XDocument xdoc2 = XDocument.Load("xml2.xml");
string sku = String.Empty;
string searchedID = "2";
//1.searching through an xml file based on path
foreach (XElement message in xdoc1.XPathSelectElements("Envelope/Message"))
{
if (message.Element("MessageID").Value.Equals(searchedID))
{
//2.grabbing another node's details
sku = message.XPathSelectElement("Inventory/SKU").Value;
}
}
foreach (XElement message in xdoc2.XPathSelectElements("Envelope/Message"))
{
if (message.XPathSelectElement("Inventory/SKU") != null && message.XPathSelectElement("Inventory/SKU").Value.Equals(sku))
{
//removing a node
message.Remove();
}
}
xdoc2.Save("xml2_del.xml");
}

Deleting node from string with xml structure

I have an string parameter with xml content in it. Basically the string have an XML inside.
string S = funcThatReturnsXML (parameters);
S have the next text:
<?xml version="1.0" encoding="utf-8" ?>
<tagA>
<tagB>
<tagBB>
..
.
.
</tagBB>
.
.
</tagB>
<tagC>
..
..
.
</tagC>
</tagA>
The funcThatReturnsXML (parameters) creates an XmlDocument object but the return it as a string, I cant change this function, to much stuff works with it.
Tried to create XmlDocument objetc but the SelectSingleNode return null.
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.LoadXml(S);
XmlNode root = xmlDoc.SelectSingleNode("tagB");
How can I delete from string S (not XML Object) specific node, for example <tagB>
EDIT: this is the XML I tested with:
<?xml version="1.0" ?>
- <Request xmlns:xsi="http://www.mysite.com" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
- <info xmlns="http://www.mysite.com">
<RequestTR>54</RequestTR>
<time>2013-12-22</time>
</info>
- <Parameters xmlns="http://www.mysite.com">
<id>3</id>
<name>2</name>
</Parameters>
<title>Request</title>
</Request>

Try this:
string S = funcThatReturnsXML(parameters);
var doc = XDocument.Parse(S);
var nodeToRemove = doc.Descendants("tagB");
nodeToRemove.Remove();
That will remove all nodes named "tagB" from string S which contains xml.
UPDATE 1:
Sorry, i missed to include one more line:
S = doc.ToString();
My first code above removed "tagB" from doc but didnt save it back to S variable.
UPDATE 2:
I tested with following xml which contain attribute:
<tagA attribute="value">
<tagB>
<tagBB>
</tagBB>
</tagB>
<tagC></tagC>
</tagA>
and the output of Console.WriteLine(S):
<tagA attribute="value">
<tagC></tagC>
</tagA>
UPDATE 3:
Given your updated xml format, I know why my previous code didn't work for you. That was because your xml have namespace (xmlns) declared. The solution is to use LocalName when searching for the node to be removed, that will search for node name while ignoring its namespace. The follwoing example shows how to remove all "info" node:
var doc = XDocument.Parse(S);
var nodeToRemove = doc.Descendants().Where(o => o.Name.LocalName == "info");
nodeToRemove.Remove();
S = doc.ToString();

If you can determine the particular outer element to remove from the returned XML, you could use LINQ to XML:
var returnedXml = funcThatReturnsXML(parameters);
var xmlElementToRemove = funcThatReturnsOuterElement(returnedXml);
var xelement = XElement.Load("XmlDoc.txt");
xelement.Elements().Where(e => e.Name == xmlElementToRemove).Remove();
For example:
using System.Linq;
using System.Xml.Linq;
class Program
{
static void Main(string[] args)
{
// pretend this is the funThatReturnsXML return value
var returnedXml = "<tagB><tagBB></tagBB></tagB>";
// get the outer XML element name
var xmlElementToRemove = GetOuterXmlElement(returnedXml);
// load XML from where ever
var xelement = XElement.Load("XmlDoc.txt");
// remove the outer element and all subsequent elements
xelement.Elements().Where(e => e.Name == xmlElementToRemove).Remove();
}
static string GetOuterXmlElement(string xml)
{
var index = xml.IndexOf('>');
return xml.Substring(1, index - 1);
}
}
Note that the above is a "greedy" removal method, if there is more than once element with the name returned via the GetOuterXmlElemet method they will all be removed. If you want a specific instance to be removed then you will require something more sophisticated.

Building on your edit:
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.LoadXml(S);
var nodeA = xmlDoc.SelectSingleNode("/tagA");
var nodeB = nodeA.SelectSingleNode("tagB");
nodeA.RemoveChild(nodeB);
To remove (possibly) multiple tagB nodes in unknown positions, you may try:
var bees = xmlDoc.SelectNodes("//tagB");
foreach (XmlNode bee in bees) {
var parent = bee.ParentNode;
parent.RemoveChild(bee);
}

Filter XDocument more efficiently

I would like to filter with high performance XML elements from an XML document.
Take for instance this XML file with contacts:
<?xml version="1.0" encoding="ISO-8859-1"?>
<?xml-stylesheet type="text/xsl" href="asistentes.xslt"?>
<contactlist evento="Cena Navidad 2010" empresa="company">
<contact type="1" id="1">
<name>Name1</name>
<email>xxxx#zzzz.es</email>
<confirmado>SI</confirmado>
</contact>
<contact type="1" id="2">
<name>Name2</name>
<email>xxxxxxxxx#zzzze.es</email>
<confirmado>Sin confirmar</confirmado>
</contact>
</contaclist>
My current code to filter from this XML document:
using System;
using System.Xml.Linq;
class Test
{
static void Main()
{
string xml = #" the xml above";
XDocument doc = XDocument.Parse(xml);
foreach (XElement element in doc.Descendants("contact")) {
Console.WriteLine(element);
var id = element.Attribute("id").Value;
var valor = element.Descendants("confirmado").ToList()[0].Value;
var email = element.Descendants("email").ToList()[0].Value;
var name = element.Descendants("name").ToList()[0].Value;
if (valor.ToString() == "SI") { }
}
}
}
What would be the best way to optimize this code to filter on <confirmado> element content?

var doc = XDocument.Parse(xml);
var query = from contact in doc.Root.Elements("contact")
let confirmado = (string)contact.Element("confirmado")
where confirmado == "SI"
select new
{
Id = (int)contact.Attribute("id"),
Name = (string)contact.Element("name"),
Email = (string)contact.Element("email"),
Valor = confirmado
};
foreach (var contact in query)
{
...
}
Points of interest:
doc.Root.Elements("contact") selects only the <contact> elements in the document root, instead of searching the whole document for <contact> elements.
The XElement.Element method returns the first child element with the given name. No need to convert the child elements to a list and take the first element.
The XElement and XAttribute classes provide a wide selection of convenient conversion operators.

You could use LINQ:
foreach (XElement element in doc.Descendants("contact").Where(c => c.Element("confirmado").Value == "SI"))