Question

I am trying to add a sub category to Messages in my xml statement Is there a way I can do this GroupMessages -> Message -> GroupMessage :

        var groups = xDoc.Descendants("Group")
            .Select(n => new
            {
                GroupName = n.Element("GroupName").Value,
                GroupHeader = n.Element("GroupHeader").Value,
                TimeCreated = DateTime.Parse(n.Element("TimeAdded").Value),
                Tags = n.Element("Tags").Value, 
                Messages = n.Element("GroupMessages").Value
                //line above
            })
            .ToList();
        dataGrid2.ItemsSource = groups;

In my method GroupMessages contains both MessageID and GroupMessage and it is listing both in my datagrid within the one container. So I tried this but it lists nothing:

 Messages = n.Descendants("GroupMessages").Select(nd => nd.Element("GroupMessage").Value)

My XML looks like this:

<Group>
<TimeAdded>2012-04-27T10:23:50.7153613+01:00</TimeAdded>
<GroupName>Group</GroupName>
<GroupHeader>Header</GroupHeader>
<GroupMessages>
<Message>
<MessageID>1</MessageID>
<GroupMessage>Message</GroupMessage>
<MessageGroup/>
</Message>
</GroupMessages>
</Group>

I have also tried:

Messages = n.Descendants("GroupMessages").Select(nd => nd.Descendants("Message").Select(nde => nde.Element("GroupMessage").Value))

To no avail?

Update:

    private void ListGroups_Click(object sender, RoutedEventArgs e)
    {
        string uriGroup = "http://localhost:8000/Service/Group";
        XDocument xDoc = XDocument.Load(uriGroup);
        var groups = xDoc.Descendants("Group")
                    .Select(n => new
        {
            GroupName = n.Element("GroupName").Value,
            GroupHeader = n.Element("GroupHeader").Value,
            TimeCreated = n.Element("TimeAdded").Value,
            Tags = n.Element("Tags").Value,
            Messages = n.Element("GroupMessages").Descendants("Message").Select(nd => new
            {
                //Id = nd.Element("MessageID").Value,
                Message = nd.Element("GroupMessage").Value
            }).FirstOrDefault()
        })
        .ToList();
        dataGrid2.ItemsSource = groups;
    }

Unfortunatley this method shows “Collection” inside the cell in the datagrid. If I try ToArray it will show an array message inside the cell. Is there a way to actually display the GroupMessage? Not sure how you set the child elements of a datagrid?

Answer 1

At the most basic level, you can do this to get a single message (the first one):

var groups = from grp in xDoc.Descendants("Group")
             select new { 
                GroupName = grp.Element("GroupName").Value,
                GroupHeader = grp.Element("GroupHeader").Value,
                TimeCreated = DateTime.Parse(grp.Element("TimeAdded").Value),
                Message = grp.Element("GroupMessages").Element("Message").Element("GroupMessage").Value
             };

However, I assume that you want Messages to be a list of messages with both ID and Message. In that case, consider this:

var groups = from grp in xDoc.Descendants("Group")
             select new { 
                GroupName = grp.Element("GroupName").Value,
                GroupHeader = grp.Element("GroupHeader").Value,
                TimeCreated = DateTime.Parse(grp.Element("TimeAdded").Value),
                Messages = grp.Element("GroupMessages")
                             .Descendants("Message")
                             .Select(msg => new { 
                                 Id = msg.Element("MessageID").Value, 
                                 Message = msg.Element("GroupMessage").Value
                             }).ToList()
             };

However, I strongly stress that all this usage of anonymous classes is just going to cause confusion. If you have a class for Group and Message then use those.

Note that the problem you’re having is you’re ignoring the XML structure and selecting random elements. To get the value out of a single element, you’re going to need to select exactly that element, and ask for .Value. Selecting it’s parent, or it’s parent’s parent (as you did) is not enough.