Csharp/C Sharp/XML LINQ/Query
Содержание
- 1 A Simple XML Query Using LINQ to XML
- 2 Get Node by type with OfType
- 3 Query string array by its element length
- 4 Query XML document by attribute
- 5 Query XML document with Ancestors and First
- 6 Query XML document with where clause
- 7 Query XML with Descendants
- 8 Query XML with namespace
- 9 Use Linq query to get XML document elements
- 10 use Linq to query an XML document
A Simple XML Query Using LINQ to XML
<source lang="csharp"> using System; using System.Linq; using System.Xml.Linq; public class MainClass {
public static void Main() {
XElement books = XElement.Parse(
@"<books>
<book>
<title>P</title>
<author>J</author>
</book>
<book>
<title>W</title>
<author>B</author>
</book>
<book>
<title>C</title>
<author>A</author>
</book>
</books>");
var titles =
from book in books.Elements("book")
where (string)book.Element("author") == "J"
select book.Element("title");
foreach (var title in titles)
Console.WriteLine(title.Value);
}
}
</source>
Get Node by type with OfType
<source lang="csharp"> using System; using System.Collections; using System.Collections.Generic; using System.Linq; using System.Text; using System.Data.Linq; using System.Reflection; using System.Xml.Linq; class Program {
static void Main(string[] args) {
XElement xml = XElement.Load("Employee.xml");
IEnumerable<XComment> record = xml.Nodes().OfType<XComment>();
foreach (XComment comment in record)
Console.WriteLine(comment);
}
}
</source>
Query string array by its element length
<source lang="csharp"> using System; using System.Linq; class HelloWorld {
static void Main() {
string[] words = { "hello", "wonderful", "linq", "beautiful", "world" };
var shortWords = from word in words
where word.Length <= 5
select word;
foreach (var word in shortWords)
Console.WriteLine(word);
}
}
</source>
Query XML document by attribute
<source lang="csharp"> using System; using System.Collections; using System.Collections.Generic; using System.Linq; using System.Text; using System.Data.Linq; using System.Reflection; using System.Xml.Linq; class Program {
static void Main(string[] args) {
XElement xml = XElement.Load("Employee.xml");
var query = from s in xml.Elements("salary").Elements("idperson")
where (int)s.Attribute("year") == 2004
select s;
foreach (var record in query) {
Console.WriteLine("Amount: {0}", (string)record.Attribute("salaryyear"));
}
}
}
</source>
Query XML document with Ancestors and First
<source lang="csharp"> using System; using System.Collections; using System.Collections.Generic; using System.Linq; using System.Text; using System.Data.Linq; using System.Reflection; using System.Xml.Linq; class Program {
static void Main(string[] args) {
XElement xml = XElement.Load("Employee.xml");
var record = xml.Descendants("firstname").First();
foreach (var tag in record.Ancestors())
Console.WriteLine(tag.Name);
}
}
</source>
Query XML document with where clause
<source lang="csharp"> using System; using System.Collections; using System.Collections.Generic; using System.Linq; using System.Text; using System.Data.Linq; using System.Reflection; using System.Xml.Linq; class Program {
static void Main(string[] args) {
XElement xml = XElement.Load(@"Employee.xml");
var query = from p in xml.Elements("person")
where (int)p.Element("id") == 1
select p;
foreach (var record in query) {
Console.WriteLine("Employee: {0} {1}",
record.Element("firstname"),
record.Element("lastname"));
}
}
}
</source>
Query XML with Descendants
<source lang="csharp"> using System; using System.Collections; using System.Collections.Generic; using System.Linq; using System.Text; using System.Data.Linq; using System.Reflection; using System.Xml.Linq; class Program {
static void Main(string[] args) {
XElement xml = XElement.Load("Employee.xml");
var query = from p in xml.Descendants("person")
join s in xml.Descendants("id")
on (int)p.Element("id") equals (int)s.Attribute("id")
select new {
FirstName = p.Element("firstname").Value,
LastName = p.Element("lastname").Value,
Amount = s.Attribute("salaryyear").Value
};
foreach (var record in query) {
Console.WriteLine("Employee: {0} {1}, Salary {2}", record.FirstName,
record.LastName,
record.Amount);
}
}
}
</source>
Query XML with namespace
<source lang="csharp"> using System; using System.Collections; using System.Collections.Generic; using System.Linq; using System.Text; using System.Data.Linq; using System.Reflection; using System.Xml.Linq; class Program {
static void Main(string[] args) {
XElement xml = XElement.Load("Hello.xml");
XNamespace o = "urn:schemas-microsoft-com:office:office";
var query = from w in xml.Descendants(o + "Author")
select w;
foreach (var record in query)
Console.WriteLine("Author: {0}", (string)record);
}
}
</source>
Use Linq query to get XML document elements
<source lang="csharp"> using System; using System.Collections; using System.Collections.Generic; using System.Linq; using System.Text; using System.Data.Linq; using System.Reflection; using System.Xml.Linq; class Program {
static void Main(string[] args) {
XElement xml = XElement.Load("Employee.xml");
XElement html = new XElement("HTML",
new XElement("BODY",
new XElement("TABLE",
new XElement("TH", "ID"),
new XElement("TH", "Full Name"),
new XElement("TH", "Role"),
from p in xml.Descendants("person")
join r in xml.Descendants("role") on (int)p.Element("idrole") equals (int)r.Element("id")
select new XElement("TR",
new XElement("TD", p.Element("id").Value),
new XElement("TD", p.Element("firstname").Value + " " + p.Element("lastname").Value),
new XElement("TD", r.Element("roledescription").Value)))));
html.Save(@"C:\People.html");
}
}
</source>
use Linq to query an XML document
<source lang="csharp"> using System; using System.Linq; using System.Xml; using System.Xml.Linq;
static class HelloLinqToXml {
static void Main() {
var books = new[] {
new {Title="A", Publisher="M", Year=2005 },
new {Title="W", Publisher="M", Year=2006 },
new {Title="R", Publisher="M", Year=2006 }
};
XElement xml = new XElement("books",
from book in books
where book.Year == 2006
select new XElement("book",
new XAttribute("title", book.Title),
new XElement("publisher", book.Publisher)
)
);
Console.WriteLine(xml);
}
}
</source>
