How to Deserialize XML document

Question

How do I Deserialize this XML document:

<?xml version="1.0" encoding="utf-8"?>
<Cars>
  <Car>
    <StockNumber>1020</StockNumber>
    <Make>Nissan</Make>
    <Model>Sentra</Model>
  </Car>
  <Car>
    <StockNumber>1010</StockNumber>
    <Make>Toyota</Make>
    <Model>Corolla</Model>
  </Car>
  <Car>
    <StockNumber>1111</StockNumber>
    <Make>Honda</Make>
    <Model>Accord</Model>
  </Car>
</Cars>

I have this:

[Serializable()]
public class Car
{
    [System.Xml.Serialization.XmlElementAttribute("StockNumber")]
    public string StockNumber{ get; set; }

    [System.Xml.Serialization.XmlElementAttribute("Make")]
    public string Make{ get; set; }

    [System.Xml.Serialization.XmlElementAttribute("Model")]
    public string Model{ get; set; }
}

.

[System.Xml.Serialization.XmlRootAttribute("Cars", Namespace = "", IsNullable = false)]
public class Cars
{
    [XmlArrayItem(typeof(Car))]
    public Car[] Car { get; set; }

}

.

public class CarSerializer
{
    public Cars Deserialize()
    {
        Cars[] cars = null;
        string path = HttpContext.Current.ApplicationInstance.Server.MapPath("~/App_Data/") + "cars.xml";

        XmlSerializer serializer = new XmlSerializer(typeof(Cars[]));

        StreamReader reader = new StreamReader(path);
        reader.ReadToEnd();
        cars = (Cars[])serializer.Deserialize(reader);
        reader.Close();

        return cars;
    }
}

that don't seem to work :-(

Answer 1

Here's a working version. I changed the XmlElementAttribute labels to XmlElement because in the xml the StockNumber, Make and Model values are elements, not attributes. Also I removed the reader.ReadToEnd(); (that function reads the whole stream and returns a string, so the Deserialze() function couldn't use the reader anymore...the position was at the end of the stream). I also took a few liberties with the naming :).

Here are the classes:

[Serializable()]
public class Car
{
    [System.Xml.Serialization.XmlElement("StockNumber")]
    public string StockNumber { get; set; }

    [System.Xml.Serialization.XmlElement("Make")]
    public string Make { get; set; }

    [System.Xml.Serialization.XmlElement("Model")]
    public string Model { get; set; }
}


[Serializable()]
[System.Xml.Serialization.XmlRoot("CarCollection")]
public class CarCollection
{
    [XmlArray("Cars")]
    [XmlArrayItem("Car", typeof(Car))]
    public Car[] Car { get; set; }
}

The Deserialize function:

CarCollection cars = null;
string path = "cars.xml";

XmlSerializer serializer = new XmlSerializer(typeof(CarCollection));

StreamReader reader = new StreamReader(path);
cars = (CarCollection)serializer.Deserialize(reader);
reader.Close();

And the slightly tweaked xml (I needed to add a new element to wrap <Cars>...Net is picky about deserializing arrays):

<?xml version="1.0" encoding="utf-8"?>
<CarCollection>
<Cars>
  <Car>
    <StockNumber>1020</StockNumber>
    <Make>Nissan</Make>
    <Model>Sentra</Model>
  </Car>
  <Car>
    <StockNumber>1010</StockNumber>
    <Make>Toyota</Make>
    <Model>Corolla</Model>
  </Car>
  <Car>
    <StockNumber>1111</StockNumber>
    <Make>Honda</Make>
    <Model>Accord</Model>
  </Car>
</Cars>
</CarCollection>

Answer 2

How about you just save the xml to a file, and use xsd to generate C# classes?

1. Write the file to disk (I named it foo.xml)
2. Generate the xsd: xsd foo.xml
3. Generate the C#: xsd foo.xsd /classes

Et voila - and C# code file that should be able to read the data via XmlSerializer:

    XmlSerializer ser = new XmlSerializer(typeof(Cars));
    Cars cars;
    using (XmlReader reader = XmlReader.Create(path))
    {
        cars = (Cars) ser.Deserialize(reader);
    }

(include the generated foo.cs in the project)

Answer 3

How about a generic class to deserialize an XML document

//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// Generic class to load any xml into a class
// used like this ...
// YourClassTypeHere InfoList = LoadXMLFileIntoClass<YourClassTypeHere>(xmlFile);

using System.IO;
using System.Xml.Serialization;

public static T LoadXMLFileIntoClass<T>(string xmlFile)
{
    T returnThis;
    XmlSerializer serializer = new XmlSerializer(typeof(T));
    if (!FileAndIO.FileExists(xmlFile))
    {
        Console.WriteLine("FileDoesNotExistError {0}", xmlFile);
    }
    returnThis = (T)serializer.Deserialize(new StreamReader(xmlFile));
    return (T)returnThis;
}

This part may, or may not be necessary. Open the XML document in Visual Studio, right click on the XML, choose properties. Then choose your schema file.

Answer 4

For Beginners

I found the answers here to be very helpful, that said I still struggled (just a bit) to get this working. So, in case it helps someone I'll spell out the working solution:

XML from Original Question. The xml is in a file Class1.xml, a path to this file is used in the code to locate this xml file.

I used the answer by @erymski to get this working, so created a file called Car.cs and added the following:

using System.Xml.Serialization;  // Added

public class Car
{
    public string StockNumber { get; set; }
    public string Make { get; set; }
    public string Model { get; set; }
}

[XmlRootAttribute("Cars")]
public class CarCollection
{
    [XmlElement("Car")]
    public Car[] Cars { get; set; }
}

The other bit of code provided by @erymski ...

using (TextReader reader = new StreamReader(path))
{
  XmlSerializer serializer = new XmlSerializer(typeof(CarCollection));
  return (CarCollection) serializer.Deserialize(reader);
}

... goes into your main program (Program.cs), in static CarCollection XCar() like this:

using System;
using System.IO;
using System.Xml.Serialization;

namespace ConsoleApp2
{
    class Program
    {

        public static void Main()
        {
            var c = new CarCollection();

            c = XCar();

            foreach (var k in c.Cars)
            {
                Console.WriteLine(k.Make + " " + k.Model + " " + k.StockNumber);
            }
            c = null;
            Console.ReadLine();

        }
        static CarCollection XCar()
        {
            using (TextReader reader = new StreamReader(@"C:\Users\SlowLearner\source\repos\ConsoleApp2\ConsoleApp2\Class1.xml"))
            {
                XmlSerializer serializer = new XmlSerializer(typeof(CarCollection));
                return (CarCollection)serializer.Deserialize(reader);
            }
        }
    }
}

Hope it helps :-)

Answer 5

Kevin's anser is good, aside from the fact, that in the real world, you are often not able to alter the original XML to suit your needs.

There's a simple solution for the original XML, too:

[XmlRoot("Cars")]
public class XmlData
{
    [XmlElement("Car")]
    public List<Car> Cars{ get; set; }
}

public class Car
{
    public string StockNumber { get; set; }
    public string Make { get; set; }
    public string Model { get; set; }
}

And then you can simply call:

var ser = new XmlSerializer(typeof(XmlData));
XmlData data = (XmlData)ser.Deserialize(XmlReader.Create(PathToCarsXml));

Answer 6

Try this Generic Class For Xml Serialization & Deserialization.

public class SerializeConfig<T> where T : class
{
    public static void Serialize(string path, T type)
    {
        var serializer = new XmlSerializer(type.GetType());
        using (var writer = new FileStream(path, FileMode.Create))
        {
            serializer.Serialize(writer, type);
        }
    }

    public static T DeSerialize(string path)
    {
        T type;
        var serializer = new XmlSerializer(typeof(T));
        using (var reader = XmlReader.Create(path))
        {
            type = serializer.Deserialize(reader) as T;
        }
        return type;
    }
}