CODEWITHSUNDEEP
c#xmlwpflinqlinq-to-xml
Milne
Milne

Reputation: 848

Remove child XML node from parent with where clause

Really new to LINQ and XML. I was hoping someone could tell me what I'm doing wrong in trying to remove a child node from an XElement.

Here is a sample of my XML: (I am trying to remove the "Relation" that corresponds to the user selected relation)

<Bill>
  <Element>
    <Name>AccountNumber</Name>
    <Regex></Regex>
    <Left></Left>
    <Right></Right>
    <Top></Top>
    <Bottom></Bottom>
    <Index>0</Index>
    <Relations></Relations>
  </Element>
  <Element>
    <Name>BillDate</Name>
    <Regex></Regex>
    <Left></Left>
    <Right></Right>
    <Top></Top>
    <Bottom></Bottom>
    <Index>1</Index>
    <Relations>
      <Relation>AccountNumber.RightOf.Right.0</Relation>
      <Relation>AccountNumber.Below.Top.-10</Relation>
      <Relation>AccountNumber.Above.Bottom.-10</Relation>
    </Relations>
  </Element>

if my WPF GUI, When a user clicks delete on a relation, I want to remove only that relation from the parent.

This is one of the many things I have tried:

private void DeleteButton_Click(object sender, RoutedEventArgs e)
{
    List<RelationsDetailView> details = (List<RelationsDetailView>)DetailsView.ItemsSource;

    XElement parentElement = (from Node in ocrVar.Xml.Descendants("Element")
                              where Node.Element("Index").Value == ocrVar.SelectedItem.Index.ToString()
                              select Node).FirstOrDefault();
    XElement child = parentElement.Element("Relations").Elements("Relation").Where(xel => xel.Element("Relation").Value == (details[DetailsView.SelectedIndex].Relation)).FirstOrDefault();
    child.Remove();
    ocrVar.Xml.Save(ocrVar.xmlPath);
}

Upvotes: 1

Views: 1365

Answers (2)

Selman Gen&#231;
Selman Gen&#231;

Reputation: 101711

xel.Element("Relation").Value == (details[DetailsView.SelectedIndex].Relation

This condition always return false, maybe you want something like this?

(string)xel.Element("Relation") == (details[DetailsView.SelectedIndex].Relation.ToString())

Upvotes: 2

MarcinJuraszek
MarcinJuraszek

Reputation: 125660

Your Where predicate is incorrect. xel is already the <relation> element, so you don't have to callElement("Relation") again.

You should also replace XElement.Value with (string)XElement to prevent NullReferenceException.

.Where(xel => (string)xel == (details[DetailsView.SelectedIndex].Relation))

Or you can use FirstOrDefault with predicate instead of Where().FirstOrDefault() chain:

XElement child = parentElement.Element("Relations").Elements("Relation").FirstOrDefault(xel => (string)xel == details[DetailsView.SelectedIndex].Relation);

Upvotes: 3

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