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C# (Xamarin): looping through XML

I have a Xamarin (C#) project, where I am trying to loop through some XML, but for some reason my code is not working.
This is what I have now:
DeviceList = new List<DeviceInfo>();
string ResultStatus = "";
string ResultDevice = "";
var result = Encoding.Default.GetString(e.Result);
result = "<?xml version=\"1.0\" encoding=\"utf-8\"?>" + result;
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.LoadXml(result);
string xPathStatus = "ed_listdevices";
var nodes = xmlDoc.SelectNodes(xPathStatus);
foreach (XmlNode xNode in nodes) {
ResultStatus = xNode.SelectSingleNode("//status").InnerText;
ResultDevice = xNode.SelectSingleNode("//device").InnerText;
}
if (ResultStatus.ToLower() == "ok") {
XmlDocument deviceDoc = new XmlDocument();
deviceDoc.LoadXml(result);
var deviceNodes = deviceDoc.SelectNodes(xPathStatus + "/device");
//foreach(XmlNode dNode in deviceNodes) {
for (int i = 0; i < deviceNodes.Count; i++) {
DeviceList.Add(new DeviceInfo() {
DeviceID = deviceNodes[i].SelectSingleNode("//id").InnerXml,
DeviceName = deviceNodes[i].SelectSingleNode("//name").InnerXml,
DeviceExtraName = "",
DeviceOnlineStatus = deviceNodes[i].SelectSingleNode("//status").InnerXml,
Location = deviceNodes[i].SelectSingleNode("//address").InnerXml,
Time = deviceNodes[i].SelectSingleNode("//time").InnerXml
});
}
}
When I step though the code I get the "ResultStatus" and "ResultDevice" correctly, and when I get to the
for (int i = 0; i < deviceNodes.Count; i++)
the "deviceNodes" variable have a count of 91, and I can see all the individual xml elements that I am suppose to get from the webservice I am calling.
However, when I loop through deviceNodes[i] I only get values from the very first XML element (yes, the value of "i" does change). In other words, my DeviceList is filled with 91 entries with the same values.
Am I missing something obvious?? What am I doing wrong since this isn't working??
PS: I have also tried using a foreach (XmlNode node in deviceNodes) but the result was the same.

"//" in the selector tells it to search from the root node of the document. If you want to search locally under the "current" node, remove the "//"

How can I get the value from XML return boolean value?

I want to make a funtion to input value (funName) and check XML file attribute (FunName) then output XML file attribute (isEnable) boolean true or false
How can I modify this code?
My XML file
<itema>
<itemb FunName="ABC" isEnable="true"></itemb>
<itemb FunName="DEF" isEnable="false"></itemb>
</itema>
My Code
public bool FunEnable(string funName , string isEnable)
{
bool result = true;
XmlDocument xDL = new XmlDocument();
xDL.Load("C://XMLFile2.xml"); //Load XML file
XmlNode xSingleNode = xDL.SelectSingleNode("//itemb");
XmlAttributeCollection xAT = xSingleNode.Attributes; //read all Node attribute
for (int i = 0; i < xAT.Count; i++)
{
if (xAT.Item(i).Name == "isEnable")
{
Console.WriteLine(xAT.Item(i).Value); //read we want attribute content
}
}
return result;
}
Thanks a lot

Well you can try this :
public static bool FunEnable(string funNam)
{
bool result = true;
XmlDocument xDL = new XmlDocument();
xDL.Load(#"C:/XMLFile2.xml"); //Load XML file
XmlNodeList nodeList = xDL.SelectNodes("//itemb");
foreach (XmlNode node in nodeList)
{
if (node.Attributes["FunName"].Value.Equals(funNam))
{
result = Convert.ToBoolean(node.Attributes["isEnable"].Value);
break;
}
}
Console.WriteLine("with funName = "+ funNam +" isEnable equal to : " + result);
return result;
}
Output
with funName = ABC isEnable equal to : True

This is fairly trivial using LINQ to XML. You can load the document using XDocument.Load and then get your isEnable value like so:
var result = doc.Descendants("itemb")
.Where(e => (string)e.Attribute("FunName") == "ABC")
.Select(e => (bool)e.Attribute("isEnable"))
.Single();
You can see a working demo here: https://dotnetfiddle.net/MYTOl6

var xDoc = XDocument.Load(path);
bool result = (from itemb in xDoc.Descendants("itemb")
where itemb.Attribute("FunName").Value == funcName
select itemb.Attribute("isEnable").Value == "true")
.FirstOrDefault();

Well, I prefer Linq to XML..
Maybe that one works:
public bool FunEnable(string funName, string isEnable)
{
bool result = true;
XDocument xDL = XDocument.Load("C://XMLFile2.xml");
var xSingleNode = from node in xDL.Descendants("itemb")
where node.Attribute("FunName").Value == funName
select node;
if(xSingleNode.Count() > 0)
{
result = xSingleNode.ElementAt(0).Attribute("isEnable").Value == "true";
//If there is at least one node with the given name, result is set to the first nodes "isEnable"-value
}
return result;
}

Finding inner text value from XML file

When I write this code, I get only the parent tag value. I want to get their childnodes value also, please tell me about this.
XmlDocument DOC = new XmlDocument();
DOC.RemoveAll();
DOC.Load("C:\\Users\\DIGITEL EYE SYSTEM\\Desktop\\response.xml");
foreach (XmlNode AllNodes in ParentNode)
{
Project.Name = AllNodes["Name"].InnerText;
if (AllNodes.ChildNodes == DOC.GetElementsByTagName("AppBuilderForms"))
{
// Project.Forms = DOC.GetElementsByTagName("");
// String sb = AllNodes["Forms"].InnerText;
}
else if (AllNodes.ChildNodes==DOC.GetElementsByTagName("CheckMarkObject"))
{
checkmark.Name = AllNodes["Name"].InnerText;
checkmark.Label = AllNodes["Label"].InnerText;
// checkmark.IsChecked = AllNodes["IsChecked"].InnerText;
}
else if (ParentNode == DOC.GetElementsByTagName("DateTimeObject"))
{
DateTime.Name = AllNodes["Name"].InnerText;
DateTime.Label = AllNodes["Label"].InnerText;
}
else if (ParentNode == DOC.GetElementsByTagName("LocationObject"))
{
Location.Name = AllNodes["Name"].InnerText;
Location.Label = AllNodes["Label"].InnerText;
Location.Longitude = AllNodes["Longitude"].InnerText;
Location.Latitude = AllNodes["Latitude"].InnerText;
}
else if (ParentNode==DOC.GetElementsByTagName("SwitchObject"))
{
Switch.Name = AllNodes["Name"].InnerText;
Switch.Label = AllNodes["Label"].InnerText;
// Switch.IsChecked =AllNodes["IsChecked"].InnerText;
}
else if(ParentNode==DOC.GetElementsByTagName("TextViewObject"))
{
TextView.Name = AllNodes["Name"].InnerText;
TextView.Value = AllNodes["Value"].InnerText;
}
else if (ParentNode ==DOC.GetElementsByTagName("TextFieldObject"))
{
TextField.Name = AllNodes["Name"].InnerText;
TextField.Value = AllNodes["Value"].InnerText;
}
else if (ParentNode == DOC.GetElementsByTagName("PhotoPickerObject"))
{
PhotoPicker.Name = AllNodes["Name"].InnerText;
PhotoPicker.Label = AllNodes["Label"].InnerText;
}
else if (ParentNode == DOC.GetElementsByTagName("SpinWheelPickerObject"))
{
SpinWheelPicker.Name = AllNodes["Name"].InnerText;
SpinWheelPicker.Label = AllNodes["Label"].InnerText;
// SpinWheelPicker.Columns = AllNodes["Columns"].InnerText;
}
}

var xdoc = XDocument.Load(#"C:\Users\DIGITEL EYE SYSTEM\Desktop\response.xml");
var allElements = xdoc.Root.Elements();
foreach (string element in allElements)
{
//TODO add logic
}
First we'll load up the xml into a XDocument (needs .Net 3.5),
nothing odd going on here.
Second we'll select the root node and ALL
the elements under the root into a IEnumrable. You can add a filter here in the Elements() method.
Third we'll start iterating over the elements in our IEnumerable and implicitly
cast them to a string, this is a operator in the LINQ to XML lib
that just returns the XElement.Value (so if you think that's more
readable or need the whole Element for some other reason write
that! I.E XElement element in allElements)
Don't know how to do it in XmlDocument, I've totally forgotten, hopefully this might help you in case you'll go down that path (pun intended).

XmlDocument query taking two values

How I can make following query
If I have XmlDocument and it may have following xml
<EquipmentParameterModified dateTime="2011-04-06T12:03:10.00+01:00" parameter="ExtApp">
<Extensions ParameterId="External App Interface" FromParameterValue="" ToParameterValue="DISABLED"/>
</EquipmentParameterModified>
How I can check that I have EquipmentParameterModified and take values of ParameterId and ToParameterValue
Thanks for help.

XmlDocument xmldoc = new XmlDocument();
xmldoc.Load(new StringReader(xmlstr));
XmlNode node = xmldoc.GetElementsByTagName("Extensions").Item(0);
string id = node.Attributes["ParameterId"].Value;
string val = node.Attributes["ToParameterValue"].Value;

Are you trying to find the element given the 2 input search values? What do you want your output to be? If you just want to see that you have a matching element, this code should do the trick:
If yes, try something like this:
public static void Main()
{
var paramId = "External App Interface";
var toParameterValue = "DISABLED";
var xdoc = XDocument.Parse(#"
<EquipmentParameterModified dateTime='2011-04-06T12:03:10.00+01:00' parameter='ExtApp'>
<Extensions ParameterId='External App Interface' FromParameterValue='' ToParameterValue='DISABLED'/>
</EquipmentParameterModified>");
var ret = xdoc.Root
.Elements("Extensions")
.Where(e => e.Attribute("ParameterId").Value == paramId &&
e.Attribute("ToParameterValue").Value == toParameterValue)
.FirstOrDefault();
if (ret != null)
Console.WriteLine(ret.Name);
}
Update for .NET 2.0 & XmlDocument:
public static void Main()
{
var paramId = "External App Interface";
var toParameterValue = "DISABLED";
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.LoadXml(#"
<EquipmentParameterModified dateTime='2011-04-06T12:03:10.00+01:00' parameter='ExtApp'>
<Extensions ParameterId='External App Interface' FromParameterValue='' ToParameterValue='DISABLED'/>
</EquipmentParameterModified>");
XmlNode node = xmlDoc.GetElementsByTagName("Extensions")[0];
if (node.Attributes["ParameterId"].Value == paramId &&
node.Attributes["ToParameterValue"].Value == toParameterValue)
{
Console.WriteLine("Found matching node:" + node.Name);
return;
}
}

I recommend using XPath to get the element you're aiming for, do a null check, then get specific attributes of that element, doing a null check on the attribute value before calling the .Value property.

Check if XML Element exists

How can someone validate that a specific element exists in an XML file? Say I have an ever changing XML file and I need to verify every element exists before reading/parsing it.

if(doc.SelectSingleNode("//mynode")==null)....
Should do it (where doc is your XmlDocument object, obviously)
Alternatively you could use an XSD and validate against that

You can iterate through each and every node and see if a node exists.
doc.Load(xmlPath);
XmlNodeList node = doc.SelectNodes("//Nodes/Node");
foreach (XmlNode chNode in node)
{
try{
if (chNode["innerNode"]==null)
return true; //node exists
//if ... check for any other nodes you need to
}catch(Exception e){return false; //some node doesn't exists.}
}
You iterate through every Node elements under Nodes (say this is root) and check to see if node named 'innerNode' (add others if you need) exists. try..catch is because I suspect this will throw popular 'object reference not set' error if the node does not exist.

//if the problem is "just" to verify that the element exist in the xml-file before you
//extract the value you could do like this
XmlNodeList YOURTEMPVARIABLE = doc.GetElementsByTagName("YOUR_ELEMENTNAME");
if (YOURTEMPVARIABLE.Count > 0 )
{
doctype = YOURTEMPVARIABLE[0].InnerXml;
}
else
{
doctype = "";
}

Not sure what you're wanting to do but using a DTD or schema might be all you need to validate the xml.
Otherwise, if you want to find an element you could use an xpath query to search for a particular element.

How about trying this:
using (XmlTextReader reader = new XmlTextReader(xmlPath))
{
while (reader.Read())
{
if (reader.NodeType == XmlNodeType.Element)
{
//do your code here
}
}
}

additionally to sangam code
if (chNode["innerNode"]["innermostNode"]==null)
return true; //node *parentNode*/innerNode/innermostNode exists

You can validate that and much more by using an XML schema language, like XSD.
If you mean conditionally, within code, then XPath is worth a look as well.

Following is a simple function to check if a particular node is present or not in the xml file.
public boolean envParamExists(String xmlFilePath, String paramName){
try{
Document doc = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new File(xmlFilePath));
doc.getDocumentElement().normalize();
if(doc.getElementsByTagName(paramName).getLength()>0)
return true;
else
return false;
}catch (Exception e) {
//error handling
}
return false;
}

A little bit late, but if it helps, this works for me...
XmlNodeList NodoEstudios = DocumentoXML.SelectNodes("//ALUMNOS/ALUMNO[#id=\"" + Id + "\"]/estudios");
string Proyecto = "";
foreach(XmlElement ElementoProyecto in NodoEstudios)
{
XmlNodeList EleProyecto = ElementoProyecto.GetElementsByTagName("proyecto");
Proyecto = (EleProyecto[0] == null)?"": EleProyecto[0].InnerText;
}

//Check xml element value if exists using XmlReader
using (XmlReader xmlReader = XmlReader.Create(new StringReader("XMLSTRING")))
{
if (xmlReader.ReadToFollowing("XMLNODE"))
{
string nodeValue = xmlReader.ReadElementString("XMLNODE");
}
}

Just came across the same problem and the null-coalescing operator with SelectSingleNode worked a treat, assigning null with string.Empty
foreach (XmlNode txElement in txElements)
{
var txStatus = txElement.SelectSingleNode(".//ns:TxSts", nsmgr).InnerText ?? string.Empty;
var endToEndId = txElement.SelectSingleNode(".//ns:OrgnlEndToEndId", nsmgr).InnerText ?? string.Empty;
var paymentAmount = txElement.SelectSingleNode(".//ns:InstdAmt", nsmgr).InnerText ?? string.Empty;
var paymentAmountCcy = txElement.SelectSingleNode(".//ns:InstdAmt", nsmgr).Attributes["Ccy"].Value ?? string.Empty;
var clientId = txElement.SelectSingleNode(".//ns:OrgnlEndToEndId", nsmgr).InnerText ?? string.Empty;
var bankSortCode = txElement.SelectSingleNode(".//ns:OrgnlEndToEndId", nsmgr).InnerText ?? string.Empty;
//TODO finish Object creation and Upsert DB
}

string name = "some node name";
var xDoc = XDocument.Load("yourFile");
var docRoot = xDoc.Element("your docs root name");
var aNode = docRoot.Elements().Where(x => x.Name == name).FirstOrDefault();
if (aNode == null)
{
return $"file has no {name}";
}

//I am finding childnode ERNO at 2nd but last place
If StrComp(xmlnode(i).ChildNodes.Item(xmlnode(i).ChildNodes.Count - 1).Name.ToString(), "ERNO", CompareMethod.Text) = 0 Then
xmlnode(i).ChildNodes.Item(xmlnode(i).ChildNodes.Count - 1).InnerText = c
Else
elem = xmldoc.CreateElement("ERNo")
elem.InnerText = c.ToString
root.ChildNodes(i).AppendChild(elem)
End If