Question

This snippet is from this answer

var reports = from report in xml.Descendants("report")
    where report.Element("name").Value.Contains("Adjustment Report")
    select new {
        Name = report.Element("name").Value,
        Extension = report.Element("extension").Value,
        FileType = report.Element("filetype").Value,
        Fields = report.Elements("field")
            .Select(f => new {
                Name = f.Attribute("name").Value, 
                Type = f.Attribute("type").Value 
            }).ToArray()
    };

For the life of me I cannot figure out the syntax for this part in vb.net:

        Fields = report.Elements("field")
            .Select(**f =>** new {
                Name = f.Attribute("name").Value, 
                Type = f.Attribute("type").Value 
            }).ToArray()

What I’m trying to accomplish – my xml looks like this:

<items>
 <item>
  <id>data</id>
  <foto>
   <fotoname>img1.jpg</fotoname>
   <fotoorder>1</fotoorder>
  </foto>
  <foto>
   <fotoname>img2.jpg</fotoname>
   <fotoorder>2</fotoorder>
  </foto>
 </item>
</items>

I need my object to have a List (or collection of any kind) of foto elements.

Answer 1

LINQ to XML is one of the areas where VB.NET offers a completely different syntax than C#. You can use the same method chaining, but I prefer the VB.NET LINQ syntax that looks like this:

Sub Main()
    Dim myXml = <items>
                    <item>
                        <id>data</id>
                        <foto>
                            <fotoname>img1.jpg</fotoname>
                            <fotoorder>1</fotoorder>
                        </foto>
                        <foto>
                            <fotoname>img2.jpg</fotoname>
                            <fotoorder>2</fotoorder>
                        </foto>
                    </item>
                </items>

    Dim fotoElementsQuery = From f In myXml...<foto> _
                            Select f

    Dim fotoAnonymousTypeQuery = From f In myXml...<foto> _
                                 Select f.<fotoname>.Value, f.<fotoorder>.Value

    Dim fotoNamedTypeQuery = From f In myXml...<foto> _
                             Select New Foto With {.Name = f.<fotoname>.Value, .Order = f.<fotoorder>.Value}

End Sub

Public Class Foto

    Private _name As String
    Public Property Name() As String
        Get
            Return _name
        End Get
        Set(ByVal value As String)
            _name = value
        End Set
    End Property

    Private _order As Integer
    Public Property Order() As Integer
        Get
            Return _order
        End Get
        Set(ByVal value As Integer)
            _order = value
        End Set
    End Property

End Class

This gives you 3 different types of IEnumerable results.

1. fotoElementsQuery will be of type IEnumerable(Of XElement)
2. fotoAnonymousTypeQuery will be of type IEnumerable(Of <anonymous type>). The elements of the anonymous type will take on the names of the xml elements — fotoname and fotoorder.
3. fotoNamedTypeQuery will be of type IEnumeragle(Of Foto)

The LINQ queries haven’t actually executed yet in the above code. In order to get a List (and to execute the query) call either the .ToList() or .ToArray() extension method.

Update: The best way to learn about the goodness that is LINQ (and LINQ to XML) in VB.NET is by watching the How Do I Video Series by Beth Massi. http://msdn.microsoft.com/en-us/vbasic/bb466226.aspx#linq