Day: August 24, 2018

LINQ to read XML

Loading the XML File

XElement and XDocument derive from XContainer.

1. XElement class

Reads the XML elements (attributes and children)

Implements IXmlSerializable.

XElement xelement = XElement.Load(file);
IEnumerable employees = xelement.Elements();
//Read the entire XML
foreach(var employee in employees)
{
	Console.WriteLine("Reading Employee: == " + employee);
}

2. XDocument class

Reads the entire XMl document.

Reads from the single root element.

XDocument xdocument = XDocument.Load(file);
IEnumerable employees = xdocument.Elements();
foreach(var employee in employees)
{
     Console.WriteLine("Reading Employee: == " + employee);
}

Reading the Single Element

foreach(var employee in employees)
{
     Console.WriteLine("Reading Employee: == " + employee.Element("Name").Value);
}

Reading Multiple Elements

foreach(var employee in employees)
{
Console.WriteLine("Reading Employee: {0} == {1}", employee.Element("Name").Value, employee.Element("EmpId").Value);
}

Filter Elements

XElement xelement = XElement.Load(file);
var name = from nm in xelement.Elements("Employee")
    where (string)nm.Element("Sex") == "Female"
    select nm;

    Console.WriteLine("Information about Female Employees");
    foreach(XElement x in name)
    {
	Console.WriteLine(x);
    }

Filter Element within another Element

XElement xelement = XElement.Load(file);
var addresses = from address in xelement.Elements("Employee")
	where (string)address.Element("Address").Element("City") == "Alta"
	select address;

Console.WriteLine("Information about Employees in Alta City");
foreach(XElement x in addresses)
{
	Console.WriteLine(x);
}

Find Nested Elements using Descendants

XElement xelement = XElement.Load(file);
Console.WriteLine("List of all Zip codes");
foreach(XElement x in xelement.Descendants("Zip"))
{
    Console.WriteLine((string)x);
}

Sorting Elements

XElement xelement = XElement.Load(file);
IEnumerable codes = from code in xelement.Elements("Employee")
	let zip = (string)code.Element("Address").Element("Zip")
        orderby zip
	select zip;
Console.WriteLine("List and Sort all Zip Codes");
			 
foreach (string zp in codes)
	Console.WriteLine(zp);