CODEWITHSUNDEEP
c#xml
MrMiketheripper
MrMiketheripper

Reputation: 143

Working with XML under C# - Difficulties

it's me again. This time, having some issues with XML. I had everything working in VB.NET (I'll show all the code I used later) but now I'm developing something else for VB application except I'm using C# for it. Part of this involves reading an XML and populating something specific into a ListBox and then being able to click on it and get the attributes for use in other controls (description loads to a text box, etc, you'll see).

I can't seem to figure out XML for the life of me in C# however. In VB, I did it like this:

Dim games() As String = xml...<episode>.Select(Function(n) n.Value).ToArray
AvailableEpisodes.DataSource = games

Where "AvailableEpisodes" is the ListBox I wish to populate. This displayed the "This is a test" term: This is a test

And then this is the SelectedIndexChanged code: 

Dim node As XElement = xml...<episode>.First(Function(n) n.Value = AvailableEpisodes.Text)
DescriptionTextBox.Text = node.@Description
AuthorTextBox.Text = node.@Author
generatedDownloadLink = node.@DownloadLink
generatedTechName = node.@TechName
IconImage.ImageLocation = node.@IconLoc

What exactly would be the C# equivalent of this? I already tried copy-pasting (just figured I'd try it) and a couple code converters and none of them seem to work.

The goal of this application will be to be able to double click on the selected index and load these strings into another window (which I can work out by attaching the nodes to a string variable) I just need to get started.

Code I've tried:

using (XmlReader reader = XmlReader.Create(testXml))
        {
            while (reader.Read())
            {
                if ((reader.NodeType == XmlNodeType.Element) && reader.Name == "episode")
                {
                    listBox1.DataSource = reader.GetAttribute("TechName").ToList();
                }
            }
        }

But that literally just outputs this: https://i.sstatic.net/LbybZ.png Any extra information I'll toss in an edit or a reply

Thanks in advanced,

Mike

Upvotes: 0

Views: 94

Answers (3)

TTat
TTat

Reputation: 1496

Why don't you just use XML Serialization?

Assuming your XML looks something like this:

<EpisodeData>
  <Episodes>
    <Episode Description="..." Author="..." DownloadLink="..." ... />
    <Episode Description="..." Author="..." DownloadLink="..." ... />
    <Episode Description="..." Author="..." DownloadLink="..." ... />
  </Episodes>
</EpisodeData>

Create classes in C# that represents the data. Something like this:

[Serializable]
public class EpisodeData
{
    [XmlArray("Episodes")]
    [XmlArrayItem(ElementName = "Episode")]
    List<Episode> Episodes { get; set; }
}

[Serializable]
public class Episode
{
    [XmlAttribute]
    public string Description { get; set; }

    [XmlAttribute]
    public string Author { get; set; }

    [XmlAttribute]
    public string DownloadLink { get; set; }

    ...
}

Then you can deserialize and use the data like this:

EpisodeData data;
XmlSerializer serializer = new XmlSerializer(typeof(EpisodeData));
using (StreamReader sr = new StreamReader(fileName))
{
    data = (EpisodeData)serializer.Deserialize(sr);
}

// Assuming you only want to see the description.  If you want something else
// you might want to use a DataGrid to bind to each property in Episode or 
// override ToString in Episode.
List<string> descriptions = new List<string>();
foreach (Episode episode in data.Episodes)
{
    descriptions.Add(episode.Description);
}

listBox1.DataSource = descriptions;

More info on XML Serialization here: http://msdn.microsoft.com/en-us/library/58a18dwa(v=vs.110).aspx

Upvotes: 0

vbn
vbn

Reputation: 799

Is "This is a test" supposed to be one single item in the ListBox? If it is, your logic in the C# code is wrong. Indeed, reader.GetAttribute("TechName").ToList() will return an array like this

["T","h","i", "s", " ", "i", "s", " ", "t", "e", "s", "t"]

Therefore, the text gets broken up into many items in the ListBox.

To read all nodes in the xml documents into ListBox, you have to create a temporary list to hold all the results read from the xml, then at the end bind the list to ListBox listBox1.DataSource = results

Upvotes: 0

Sergey Berezovskiy
Sergey Berezovskiy

Reputation: 236318

Its easy: ... corresponds to Descendants. <foo> corresponds to element name. @bar corresponds to attribute name.

var xml = XDocument.Load(path_to_xml);
var node = xml.Descendants("episode")
              .First(n => n.Value == AvailableEpisodes.Text);

DescriptionTextBox.Text = (string)node.Attribute("Description");
AuthorTextBox.Text = (string)node.Attribute("Author");
generatedDownloadLink = (string)node.Attribute("DownloadLink");
generatedTechName = (string)node.Attribute("TechName");
IconImage.ImageLocation = (string)node.Attribute("IconLoc");

Note - if there is no matching node, then First will throw exception. Usually you should use FirstOrDefault in such case and then check node for null.

Upvotes: 2

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