Can't read xml for DataSet?

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First I create DataSet object

C#

DataSet ds = new DataSet();

Then I load xmlscheme.

C#

ds.ReadXmlSchema("C:/Users/Levan/Dcuments/Visual Studio 2012/Projects/Crashop/CarLibrary/CarDataSet.xsd");

It load's fine.I use Dataset visualizer for debugging.Xmlscheme has following structure Table
Cars(carname(string),carnumber(string),cardiscription(string),CarID(int)).Than I try loadxml

C#

ds.ReadXml("C:/Users/Levan/Documents/Visual Studio 2012/Projects/Crashop/CarLibrary/CarPark.xml");

xml file has following structure

XML

<?xml version="1.0" standalone="yes"?>
<NewDataSet>
  <Cars>
    <carname>BMW</carname>
    <carnumber>AA2935IO</carnumber>
    <cardiscription>Nice car</cardiscription>
    <CarID>1</CarID>
  </Cars>
  <Cars>
    <carname>Mersedes</carname>
    <carnumber>AA2235IO</carnumber>
    <cardiscription>Nice car</cardiscription>
    <CarID>2</CarID>
  </Cars>
</NewDataSet>

In result no errors,but empty table.

C#

ds.Tables["Cars"].Rows.Add("BMW","AA2935IO","Nice Car",1);

Works fine.But i want to figure out how to read from XML file.In example which i use everything good and i didn't find appropriate solution for me.

Posted 20-Sep-15 9:13am

Inimicos

Updated 20-Sep-15 10:32am

v3

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Comments

George Swan 20-Sep-15 16:26pm

In your XML schema you have
'canumber(string)' - shouldn't that be carnumber NOT canumber

Inimicos 20-Sep-15 16:31pm

сarnumber there i wrote here wrong.

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Maciej Los · Accepted Answer · 2015-09-20T11:19:00

There is - at least - few ways to read/write xml data, for example:
1. Linq to XML[^]
2. Xml Serialization/deserialization[^]

Based on this[^] i'd suggest to create custom class collection as follow:

Car class is used to store data about single car.

C#

public class Car
{
    private string sCarName = string.Empty;
    private string sCarNumber = string.Empty;
    private string sCarDescription = string.Empty;
    private int iCarId = 0;

    //contructor
    public Car(string _CarName, string _CarNumber, string _CarDescription, int _CarId)
    {
        sCarName = _CarName;
        sCarNumber = _CarNumber;
        sCarDescription = _CarDescription;
        iCarId = _CarId;
    }

    public string CarName
    {
        get{return sCarName;}
        set{sCarName = value;}
    }

    public string CarNumber
    {
        get{return sCarNumber;}
        set{sCarNumber = value;}
    }

    public string CarDescription
    {
        get{return sCarDescription;}
        set{sCarDescription = value;}
    }

    public int CarID
    {
        get{return iCarId;}
        set{iCarId = value;}
    }

}

Cars class inherits from CollectionBase and is used to store list of cars (of type: Car):

C#

public class Cars : CollectionBase
{

    public Car Item(int index)
    {
	if(index<0 || index>List.Count-1)
		throw new IndexOutOfRangeException();
		
	return (Car)List[index];
    }

    public Car Add(Car _car)
    {
        _car.CarID = List.Count + 1;
        int index = List.Add(_car);
        return (Car)List[index];
    }

    void Remove(int index)
    {
        if(index<0 || index>List.Count-1)
            throw new IndexOutOfRangeException();

        List.Remove(index);
    }

}

Usage:

C#

XDocument xdoc = XDocument.Load(@"D:\CarPark.xml");
Cars CarPark = new Cars(); //collection of cars

    //fetch data from xml document
    //create List<Car>
var cars = xdoc.Descendants("Car")
        .Select(c=> new Car
        (
            (string)c.Element("CarName"),
            (string)c.Element("CarNumber"),
            (string)c.Element("CarDescription"),
            (int)c.Element("CarID")
        ));
//fill collection: add cars from List<Car>
foreach(Car c in cars)
{
    CarPark.Add(c);
}

    //CarPark is ready to use, you can access single car using Item method.
Car cr = CarPark.Item(0);
cr.CarName = "Seat Toledo";

Note: you have to make some minor changes in xml file before you'll be able to use it:

XML

<?xml version="1.0" encoding="utf-8" standalone="yes"?>
<Cars>
  <Car>
    <CarName>BMW</CarName>
    <CarNumber>AA2935IO</CarNumber>
    <CarDescription>Nice car</CarDescription>
    <CarID>1</CarID>
  </Car>
  <Car>
    <CarName>Mersedes</CarName>
    <CarNumber>AA2235IO</CarNumber>
    <CarDescription>Nice car</CarDescription>
    <CarID>2</CarID>
  </Car>
</Cars>

If you want to implement Save method, which will dump all CarPark data into xml file, you have to loop through the collection of Cars:

C#

XDocument xdoc = new XDocument();
XElement root = new XElement("Cars");
foreach(Car c in CarPark)
{
    root.Add(new XElement("Car",
                    new XElement("CarName", c.CarName),
                    new XElement("CarNumber", c.CarNumber),
                    new XElement("CarDescription", c.CarDescription),
                    new XElement("CarID", c.CarID)));
}
xdoc.Add(root);
xdoc.Save(@"FullPathToXmlFile.xml");