Question

I’m probably getting mad about it and there must be some trivial error in this. I’m trying to get from this XML code the “Value” attributes for each attribute Name == Eyes.

        <?xml version="1.0" encoding="utf-8"?>
<Collection xmlns:p="http://schemas.microsoft.com/livelabs/pivot/collection/2009" SchemaVersion="1.0" Name="Actresses" xmlns="http://schemas.microsoft.com/collection/metadata/2009">
  <FacetCategories>
    <FacetCategory Name="Nationality" Type="LongString" p:IsFilterVisible="true" p:IsWordWheelVisible="true" p:IsMetaDataVisible="true" />
    <FacetCategory Name="Eyes" Type="LongString" p:IsFilterVisible="true" p:IsWordWheelVisible="true" p:IsMetaDataVisible="true" />
  </FacetCategories>
  <Items ImgBase="Actresses_files\go144bwo.0ao.xml" HrefBase="http://www.imdb.com/name/">
    <Item Id="0" Img="#0" Name="Virginie Ledoyen" Href="nm0001461/">
      <Description> blablabla blablabla  blablabla blablabla  blablabla blablabla  blablabla blablabla  blablabla blablabla  blablabla blablabla  blablabla blablabla  blablabla blablabla </Description>
      <Facets>
        <Facet Name="Nationality">
          <LongString Value="French" />
        </Facet>
         <Facet Name="Eyes">
          <LongString Value="Blue" />
        </Facet>

      </Facets>
    </Item>
    <Item Id="1" Img="#1" Name="Meiko Kaji" Href="nm0435299/">
      <Description> blablabla blablabla  blablabla blablabla  blablabla blablabla  blablabla blablabla  blablabla blablabla  blablabla blablabla  blablabla blablabla  blablabla blablabla </Description>

      <Facets>
        <Facet Name="Nationality">
          <LongString Value="Japanese" />
        </Facet>
        <Facet Name="Eyes">
          <LongString Value="Black" />
        </Facet>
      </Facets>      
    </Item>

  </Items>
</Collection>

I need to populate a combobox with those attributes. My code is something like:

XNamespace fix = "http://schemas.microsoft.com/collection/metadata/2009";
IEnumerable<XElement> list2 =
                    from item in document.Descendants(fix + "Facet")
                    where (string)item.Attribute("Name") == "Eyes"
                    select item;
foreach (XElement x in list2)
{
this.comboBox2.Items.Add(x.Element("LongString").Attribute("Value").Value);
}

It turns out that the object is null before calling the method if I fix a watch on:

x.Element(“LongString”).Attribute(“Value”).Value;

I know it’s probably something I’m missing in traversing XML, but I don’t know why it turns out null, since if I try a dumb watch on (x.Value) then it’s not null.

Answer 1

The LongString element is in the http://schemas.microsoft.com/collection/metadata/2009 schema, so you need that as well:

this.comboBox2.Items.Add(x.Element(fix + "LongString")
                          .Attribute("Value").Value);

Basically, if there’s an xmlns="..." attribute somewhere in the ancestry of an element, that’s taken as the default namespace for the element (with deeper ones overriding shallower ones).

(Note that this defaulting doesn’t occur with attributes.)