Parse XML in .net framework 4.0

Question

Hello all

We have this xml:

<?xml version="1.0"?>
<categories elementCount="8">
<category OPFCategoryCopyName="Family" OPFCategoryCopyBackgroundColor="r:0.63 g:0.26 b:0.80" xml:space="preserve"/>
<category OPFCategoryCopyName="Friends" OPFCategoryCopyBackgroundColor="r:0.40 g:0.27 b:0.80" xml:space="preserve"/>
<category OPFCategoryCopyName="Holiday" OPFCategoryCopyBackgroundColor="r:0.89 g:0.15 b:0.15" xml:space="preserve"/>
<category OPFCategoryCopyName="Manager" OPFCategoryCopyBackgroundColor="r:0.85 g:0.42 b:0.72" xml:space="preserve"/>
<category OPFCategoryCopyName="Networking" OPFCategoryCopyBackgroundColor="r:0.90 g:0.40 b:0.11" xml:space="preserve"/>
<category OPFCategoryCopyName="Personal" OPFCategoryCopyBackgroundColor="r:0.26 g:0.60 b:0.00" xml:space="preserve"/>
<category OPFCategoryCopyName="Team" OPFCategoryCopyBackgroundColor="r:0.31 g:0.49 b:0.80" xml:space="preserve"/>
<category OPFCategoryCopyName="Travel" OPFCategoryCopyBackgroundColor="r:0.62 g:0.40 b:0.20" xml:space="preserve"/>
</categories>

How to parse it to get 3 parts out of it?

1. elementCount as Integer
2. OPFCategoryCopyName as String
3. OPFCategoryCopyBackgroundColor as RGB Drawing.Color

No idea where and how to start, never worked with XML parsers (just did one basic task)

Answer 1

Hi @Peter Volz

You can use either use XmlSerializer or XmlReader to Parse XML documents.

XML Serializer --> https://learn.microsoft.com/en-us/dotnet/api/system.xml.serialization.xmlserializer?view=netframework-4.8.1

XML Reader --> https://learn.microsoft.com/en-us/dotnet/standard/linq/stream-xml-fragments-xmlreader

Here is a sample using XML Serializer.

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

[XmlRoot("categories")]
public class Categories
{
    [XmlAttribute("elementCount")]
    public int ElementCount { get; set; }

    [XmlElement("category")]
    public Category[] CategoryList { get; set; }
}

public class Category
{
    [XmlAttribute("OPFCategoryCopyName")]
    public string Name { get; set; }

    [XmlAttribute("OPFCategoryCopyBackgroundColor")]
    public string BackgroundColor { get; set; }
}

class Program
{
    static void Main()
    {
        string xml = @"<?xml version=""1.0""?>
                        <categories elementCount=""8"">
                            <category OPFCategoryCopyName=""Family"" OPFCategoryCopyBackgroundColor=""r:0.63 g:0.26 b:0.80"" xml:space=""preserve""/>
                            <category OPFCategoryCopyName=""Friends"" OPFCategoryCopyBackgroundColor=""r:0.40 g:0.27 b:0.80"" xml:space=""preserve""/>
                            <category OPFCategoryCopyName=""Holiday"" OPFCategoryCopyBackgroundColor=""r:0.89 g:0.15 b:0.15"" xml:space=""preserve""/>
                            <category OPFCategoryCopyName=""Manager"" OPFCategoryCopyBackgroundColor=""r:0.85 g:0.42 b:0.72"" xml:space=""preserve""/>
                            <category OPFCategoryCopyName=""Networking"" OPFCategoryCopyBackgroundColor=""r:0.90 g:0.40 b:0.11"" xml:space=""preserve""/>
                            <category OPFCategoryCopyName=""Personal"" OPFCategoryCopyBackgroundColor=""r:0.26 g:0.60 b:0.00"" xml:space=""preserve""/>
                            <category OPFCategoryCopyName=""Team"" OPFCategoryCopyBackgroundColor=""r:0.31 g:0.49 b:0.80"" xml:space=""preserve""/>
                            <category OPFCategoryCopyName=""Travel"" OPFCategoryCopyBackgroundColor=""r:0.62 g:0.40 b:0.20"" xml:space=""preserve""/>
                        </categories>";

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

        Categories categories;
        using (StringReader reader = new StringReader(xml))
        {
            categories = (Categories)serializer.Deserialize(reader);
            Console.WriteLine("elementCount: " + categories.ElementCount);
            Console.WriteLine();

            foreach (Category category in categories.CategoryList)
            {
                Console.WriteLine("OPFCategoryCopyName: " + category.Name);
                Console.WriteLine("OPFCategoryCopyBackgroundColor: " + ParseColor(category.BackgroundColor).ToString());
                Console.WriteLine();
            }
        }

        
        Console.ReadLine();
    }

    static Color ParseColor(string colorString)
    {
        string[] components = colorString.Split(' ');
        float red = float.Parse(components[0].Substring(2));
        float green = float.Parse(components[1].Substring(2));
        float blue = float.Parse(components[2].Substring(2));

        return Color.FromArgb((int)(red * 255), (int)(green * 255), (int)(blue * 255));
    }
}

Hope this helps.

Kind Regards,

Nisha

Answer 2

In VB

        Dim someXML As XElement
        ' someXML = XElement.Load("PATH HERE")

        'for testing use literal
        someXML = <categories elementCount="8">
                      <category OPFCategoryCopyName="Family" OPFCategoryCopyBackgroundColor="r:0.63 g:0.26 b:0.80" xml:space="preserve"/>
                      <category OPFCategoryCopyName="Friends" OPFCategoryCopyBackgroundColor="r:0.40 g:0.27 b:0.80" xml:space="preserve"/>
                      <category OPFCategoryCopyName="Holiday" OPFCategoryCopyBackgroundColor="r:0.89 g:0.15 b:0.15" xml:space="preserve"/>
                      <category OPFCategoryCopyName="Manager" OPFCategoryCopyBackgroundColor="r:0.85 g:0.42 b:0.72" xml:space="preserve"/>
                      <category OPFCategoryCopyName="Networking" OPFCategoryCopyBackgroundColor="r:0.90 g:0.40 b:0.11" xml:space="preserve"/>
                      <category OPFCategoryCopyName="Personal" OPFCategoryCopyBackgroundColor="r:0.26 g:0.60 b:0.00" xml:space="preserve"/>
                      <category OPFCategoryCopyName="Team" OPFCategoryCopyBackgroundColor="r:0.31 g:0.49 b:0.80" xml:space="preserve"/>
                      <category OPFCategoryCopyName="Travel" OPFCategoryCopyBackgroundColor="r:0.62 g:0.40 b:0.20" xml:space="preserve"/>
                  </categories>

        Dim count As Integer = Integer.Parse(someXML.@elementCount)
        For Each el As XElement In someXML.Elements
            Dim name As String = el.@OPFCategoryCopyName
            Dim color As Drawing.Color
            Dim cps() As String = el.@OPFCategoryCopyBackgroundColor.Split()
            'at this point cps has three values e.g.
            ' r:0.62 
            ' g:0.40 
            ' b:0.20
            ' not clear what color format specification this is 
            ' so not sure how to proceed
            Stop
        Next

I've never seen a color spec like the one in the XML