Develop Reference

How to get enclosure url with XElement C# Console

I read multiple feed from many sources with C# Console, and i have this code where i load XML From sources:
XmlDocument doc = new XmlDocument();
doc.Load(sourceURLX);
XElement xdoc = XElement.Load(sourceURLX);
How to get enclosure url and show as variable?

If I understand your question correctly (I'm making a big assumption here) - you want to select an attribute from the root (or 'enclosing') tag, named 'url'?
You can make use of XPath queries here. Consider the following XML:
<?xml version="1.0" encoding="utf-8"?>
<root url='google.com'>
<inner />
</root>
You could use the following code to retrieve 'google.com':
String query = "/root[1]/#url";
XmlDocument doc = new XmlDocument();
doc.Load(sourceURLX);
String value = doc.SelectSingleNode(query).InnerText;
Further information about XPath syntax can be found here.
Edit: As you stated in your comment, you are working with the following XML:
<item>
<description>
</description>
<enclosure url="blablabla.com/img.jpg" />
</item>
Therefore, you can retrieve the url using the following XPath query:
/item[1]/enclosure[1]/#url

With xml like below
<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
<channel>
<title>title</title>
<link>https://www.link.com</link>
<description>description</description>
<item>
<title>RSS</title>
<link>https://www.link.com/xml/xml_rss.asp</link>
<description>description</description>
<enclosure url="https://www.link.com/media/test.wmv"
length="10000"
type="video/wmv"/>
</item>
</channel>
</rss>
You will get url by reading attribute
var document = XDocument.Load(sourceURLX);
var url = document.Root
.Element("channel")
.Element("item")
.Element("enclosure")
.Attribute("url")
.Value;
To get multiple urls
var urls = document.Descendants("item")
.Select(item => item.Element("enclosure").Attribute("url").Value)
.ToList();
Using foreach loop
foreach (var item in document.Descendants("item"))
{
var title = item.Element("title").Value;
var link = item.Element("link").Value;
var description = item.Element("description").Value;
var url = item.Element("enclosure").Attribute("url").Value;
// save values to database
}

LINQ complex delete and search query

//assume that I have the following XML file.
<warehouse>
<cat id="computer">
<item>
<SN>1</SN>
<name>Toshiba</name>
<quantity>12</quantity>
<description>CPU: CORE I5 RAM: 3 GB HD: 512 GB</description>
<price>400 USD</price>
</item>
<item>
<SN>22</SN>
<name>Toshiba</name>
<quantity>12</quantity>
<description>CPU: CORE I5 RAM: 3 GB HD: 512 GB</description>
<price>400 USD</price>
</item>
</cat>
<cat id="Stationery">
<item>
<SN> 33 </SN>
<name>note books</name>
<quantity>250</quantity>
<description>Caterpiller</description>
<price>5 USD</price>
</item>
</cat>
<cat id="Furniture">
<item>
<SN> 1 </SN>
<name>dasd</name>
<quantity>asdasd</quantity>
<description>das</description>
<price>dasd</price>
</item>
<item>
<SN>44</SN>
<name>Toshiba</name>
<quantity>12</quantity>
<description>CPU: CORE I5 RAM: 3 GB HD: 512 GB</description>
<price>400 USD</price>
</item>
<item>
</cat>
</warehouse>
question 1 : I want to Delete <item> element and its child's using linq , where <cat id="computer"> and <SN> has a specific value like 44 .
question 2 : I want to make a query using TextBox and Literal1 which return a specic <item> and its child's . this query should be in linq.
for example
XDocument xmlDoc = XDocument.Load(Server.MapPath("/XML/Cat1.xml"));
var persons = from person in xmlDoc.Descendants("item")
where person.Element("SN").Value.Equals(DropDownList1.Text)
select person;
persons.Remove();
foreach (XElement person in persons.ToList())
{
person.Remove();
}

Try this:-
xmlDoc.Root.Descendants("cat").Where(x => x.Attribute("id").Value == "computer")
.Descendants("item").Where(x => x.Element("SN").Value.Trim() == Dropdownlist.Text)
.Remove();
xmlDoc.Save(#"YourXML.xml");
And for filtering you can replace the values at specific places you like. Also, I have used Trim directly, better check for empty strings first in your actual code.
Question 2:-
var result = xmlDoc.Descendants("item")
.Where(x => x.Element("SN").Value.Trim() == Dropdownlist.Text);

Regarding question one i would do something like this using method syntax:
doc.Descendants("cat")
.Where(x => String.Equals((string)x.Attribute("id"), "computer", StringComparison.OrdinalIgnoreCase))
.Elements("item")
.Where(x => (string)x.Element("SN") == "44")
.Remove();
Basically select all your cat elements and filter by attribute id = computer. Then select all items in each of those and filter through SN = 44.

XML namespace prefix error

I am using c# to read (attempting to) an RSS feed, but I am getting an error "Namespace prefix 'cb' is not defined" , I am pretty new to XML and C# and was hoping for some help, I read a bit on creating the Namespace but I am not 100% sure I am grasping it.
Any help would be greatly appreciated.
The C# code is:
/*
Add rows by calling the AddRow method on the member variable named "<Output Name>Buffer".
For example, call MyOutputBuffer.AddRow() if your output was named "MyOutput".
*/
// Create an XmlNamespaceManager to resolve the default namespace.
XmlDocument xm = new XmlDocument();
xm.Load(Variables.USFeed.ToString());
XmlNamespaceManager nsmgr = new XmlNamespaceManager(xm.NameTable);
nsmgr.AddNamespace("rdf", "http://purl.org/rss/1.0/");
XmlNodeList xnode = xm.GetElementsByTagName("item");
foreach (XmlNode xmn in xnode)
{
XmlElement currencyElement = (XmlElement)xmn;
if (currencyElement.HasAttribute("rdf:about"))
{
Output0Buffer.AddRow();
Output0Buffer.observationPeriod = currencyElement.SelectSingleNode("cb:statistics/cb:exchangeRate/cb:observationPeriod", nsmgr).InnerText;
Output0Buffer.targetCurrency = currencyElement.SelectSingleNode("cb:statistics/cb:exchangeRate/cb:targetCurrency", nsmgr).InnerText;
Output0Buffer.baseCurrency = currencyElement.SelectSingleNode("cb:statistics/cb:exchangeRate/cb:baseCurrency", nsmgr).InnerText;
Output0Buffer.exchangeRate = double.Parse(currencyElement.SelectSingleNode("cb:statistics/cb:exchangeRate/cb:value", nsmgr).InnerText);
}
}
and the summarized version of the rss is:
<?xml version="1.0" encoding="ISO-8859-1"?>
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns="http://purl.org/rss/1.0/"
xmlns:cb="http://www.cbwiki.net/wiki/index.php/Specification_1.1"
xmlns:dc="http://purl.org/dc/elements/1.1/"
xmlns:dcterms="http://purl.org/dc/terms/"
xmlns:xsi="http://www.w3c.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.w3c.org/1999/02/22-rdf-syntax-ns#rdf.xsd">
<channel rdf:about="http://www.bankofcanada.ca/stats/assets/rates_rss/noon/en_ALL.xml">
<title xml:lang="en">Bank of Canada: Noon Foreign Exchange Rates</title>
<link>http://www.bankofcanada.ca/rates/exchange/noon-rates-5-day/</link>
<description>Current day's noon foreign exchange rates from the Bank of Canada. Published at about 12:15 ET.</description>
<items>
<rdf:Seq>
<rdf:li rdf:resource="http://www.bankofcanada.ca/stats/assets/rates_rss/noon/en_USD.xml" />
<rdf:li rdf:resource="http://www.bankofcanada.ca/stats/assets/rates_rss/noon/en_VEF.xml" />
<rdf:li rdf:resource="http://www.bankofcanada.ca/stats/assets/rates_rss/noon/en_VND.xml" />
</rdf:Seq>
</items>
</channel>
<item rdf:about="http://www.bankofcanada.ca/stats/assets/rates_rss/noon/en_USD.xml">
<title xml:lang="en">CA: 0.9382 USD = 1 CAD 2014-01-06 Bank of Canada noon rate</title>
<cb:statistics>
<cb:country>CA</cb:country>
<cb:exchangeRate>
<cb:value decimals="4">0.9382</cb:value>
<cb:baseCurrency>CAD</cb:baseCurrency>
<cb:targetCurrency>USD</cb:targetCurrency>
<cb:rateType>Bank of Canada noon rate</cb:rateType>
<cb:observationPeriod frequency="daily">2014-01-06T12:15:00-05:00</cb:observationPeriod>
</cb:exchangeRate>
</cb:statistics>
</item>
<item rdf:about="http://www.bankofcanada.ca/stats/assets/rates_rss/noon/en_ARS.xml">
<title xml:lang="en">CA: 6.1843 ARS = 1 CAD 2014-01-06 Bank of Canada noon rate</title>
<cb:statistics>
<cb:country>CA</cb:country>
<cb:exchangeRate>
<cb:value decimals="4">6.1843</cb:value>
<cb:baseCurrency>CAD</cb:baseCurrency>
<cb:targetCurrency>ARS</cb:targetCurrency>
<cb:rateType>Bank of Canada noon rate</cb:rateType>
<cb:observationPeriod frequency="daily">2014-01-06T12:15:00-05:00</cb:observationPeriod>
</cb:exchangeRate>
</cb:statistics>
</item>

You need to add "cb" to your XmlNamespaceManager in order to use "cb" in SelectSingleNode.
nsmgr.AddNamespace(
"cb",
"http://www.cbwiki.net/wiki/index.php/Specification_1.1");

XmlDocument in an array like object

I googled for hours and didn't find anything.
I'm trying to make a Metro App which is reading from an online XML Service. Getting the XML is not the problem, i'm simply doing it like this ->
var xmlDoc = await XmlDocument.LoadFromUriAsync(new Uri(url));
but now the problem is, how to convert it into a list or something readable like this.
The XML I want to read is really huge and i don't want to go through all nodes with foreach.
A simple Array/List with all nodes and innerText as Value would be awesome.
Is this possible? If yes.. how ?
The structure of my XML is like this ->
<?xml version="1.0" encoding="UTF-8"?>
<city>
...
<credit>
...
</credit>
<forecast>
<date value="2013-11-08">
...
<time value="06:00">
...
</time>
<time value="11:00">
...
</time>
<time value="17:00">
...
</time>
<time value="23:00">
...
</time>
...
</date>
<date value="2013-11-09">
<same content here>
</date>
<date value="2013-11-09">
<same content here>
</date>
</forecast>
</city>
as you can see... there's a lot of information in the XML and I need nearly everything. In Actionscript I would realize it with a XMLList and make 3 Lists of the date Tags with content, so i can use
xmllist1.time[0] - xmllist1.time[3]
xmllist2.time[0] - xmllist2.time[3]
xmllist3.time[0] - xmllist3.time[3]
to get my data.
And now i want this XMLList in C#... I hope it's possible...Thx 4 help

If I understand you correctly, you want to parse the list of "city" items from the xml.
I do something similar using XDocument and Linq like this and it should work for you:
XDocument xdoc = <add your code to get xml from url>;
var ns = xdoc.Root.GetDefaultNamespace();
var cityList = from query in xdoc.Descendants(ns + "city")
select new CityItem
{
Date = (string)query.Element(ns + "date").Attribute("value").Value,
Time = (string)query.Element(ns + "time").Attribute("value").Value
};
public class CityItem
{
public string Date {get;set;}
public string Time {get;set;}
}

Adding new RSS elements to existing RSS, without modifying existing namespace prefixes

I have an input RSS Feed with some elements already added with namespace prefix (for itunes). Without removing attribute and adding in C# again, an element, say <itunes:subtitle> is added as namespace and the element is <subtitle>
Desired output:
<rss xmlns:itunes="http://www.itunes.com/dtds/podcast-1.0.dtd/" version="2.0">
<channel>
<title>channelTitle</title>
<itunes:subtitle>subtitle_description</itunes:subtitle>
<item>
<title>item1</title>
<itunes:subtitle>A short description</itunes:subtitle>
</item>
</channel>
</rss>
Input XML:
<rss xmlns:itunes="http://www.itunes.com/dtds/podcast-1.0.dtd/" version="2.0">
<channel>
<item>
<title>item1</title>
<itunes:subtitle>A short description</itunes:subtitle>
</item>
</channel>
</rss>
How can I add another element in C#, but also maintain the existing namespace:element ? I'm having to explicitly add the namespace again in the code (and namespace should also be present in input XML, otherwise it's processing invalid XML:
See code:
XNamespace itunes = "http://www.itunes.com/dtds/podcast-1.0.dtd/";
string rssFeed = "<rss xmlns:itunes=\"http://www.itunes.com/dtds/podcast-1.0.dtd\" version=\"2.0\"><channel><item><title>item1</title><itunes:subtitle>A short description</itunes:subtitle></item></channel></rss>";
XDocument XMLDoc = XDocument.Parse(rssFeed);
XMLDoc.Root.RemoveAttributes();
XMLDoc.Root.Add(new XAttribute(XNamespace.Xmlns + "itunes", itunes.NamespaceName));
//Without adding the namespace attribute explicitly, the xmlns attribute is added instead to <subtitle> instead of <itunes:subtitle> :
XMLDoc.Element("rss").Element("channel").AddFirst(
new XElement("title", "channelTitle"),
new XElement(itunes + "subtitle", "subtitle_description")
);
gets added correctly.
However, is now changed in the input XML, output:
<rss xmlns:itunes="http://www.itunes.com/dtds/podcast-1.0.dtd/">
<channel>
<title>channelTitle</title>
<itunes:subtitle>subtitle_description</itunes:subtitle>
<item>
<title>item1</title>
<subtitle xmlns="http://www.itunes.com/dtds/podcast-1.0.dtd">A short description</subtitle>
</item>
</channel>
</rss>
Approach2:
XNamespace itunes = "http://www.itunes.com/dtds/podcast-1.0.dtd/";
string rssFeed = "<rss xmlns:itunes=\"http://www.itunes.com/dtds/podcast-1.0.dtd\" version=\"2.0\"><channel><item><title>item1</title><itunes:subtitle>A short description</itunes:subtitle></item></channel></rss>";
XDocument XMLDoc = XDocument.Parse(rssFeed);
XMLDoc.Element("rss").Element("channel").AddFirst(
new XElement("title", "channelTitle"),
new XElement(itunes + "subtitle", "subtitle_description")
);
Console.WriteLine(XMLDoc);
Output:
<rss xmlns:itunes="http://www.itunes.com/dtds/podcast-1.0.dtd" version="2.0">
<channel>
<title>channelTitle</title>
<subtitle xmlns="http://www.itunes.com/dtds/podcast-1.0.dtd/">subtitle_description</subtitle>
<item>
<title>item1</title>
<itunes:subtitle>A short description</itunes:subtitle>
</item>
</channel>
</rss>
As much as my question is really long, I'm hoping to get few lines of code as an answer, sure there must be something simple I'm missing :)

I can't reproduce the problem you say you face, the following straightforward sample
string rssFeed = "<rss xmlns:itunes=\"http://www.itunes.com/dtds/podcast-1.0.dtd\" version=\"2.0\"><channel><item><title>item1</title><itunes:subtitle>A short description</itunes:subtitle></item></channel></rss>";
XDocument XMLDoc = XDocument.Parse(rssFeed);
XNamespace itunes = XMLDoc.Root.GetNamespaceOfPrefix("itunes");
XMLDoc.Element("rss").Element("channel").AddFirst(
new XElement("title", "channelTitle"),
new XElement(itunes + "subtitle", "subtitle_description")
);
XMLDoc.Save(Console.Out);
Console.WriteLine();
when run with .NET 3.5, outputs
<rss xmlns:itunes="http://www.itunes.com/dtds/podcast-1.0.dtd" version="2.0">
<channel>
<title>channelTitle</title>
<itunes:subtitle>subtitle_description</itunes:subtitle>
<item>
<title>item1</title>
<itunes:subtitle>A short description</itunes:subtitle>
</item>
</channel>
</rss>
Looking closer at your code, the only problem is see is that some samples use the URI http://www.itunes.com/dtds/podcast-1.0.dtd while some have http://www.itunes.com/dtds/podcast-1.0.dtd/ with a trailing slash "/". So that might be the reason why you run into problems.