CODEWITHSUNDEEP
c#xmllinqlinq-to-xml
Harry Boy
Harry Boy

Reputation: 4747

Reading the result of LINQ and XDocument

I'm trying to parse a visual studio resource file that contains various translated strings like so:

<data name="InvalidGroupType" xml:space="preserve">
  <value>La sélection du type de groupe n'est pas valide.</value>
</data>
<data name="ProgressFailure" xml:space="preserve">
  <value>Liste des échecs</value>
</data>
<data name="Loronix" xml:space="preserve">
  <value>Loronix</value>
</data>
<data name="InputString" xml:space="preserve">
  <value>Entrée</value>
</data>

As well as other stuff. I just want the data name and value strings.

I tried to parse this file line by line using the following:

StreamReader fileMain = new StreamReader(MainFile);
while ((line = fileMain.ReadLine()) != null)
{
    string data = checkForData(line); --checks each line for "<data name="
    if( data.Length > 0)
       StringsToTranslatelist.Add(data);
}

But I guessed there must be a better way to do this. So I used a LINQ like so:

XDocument xDoc = XDocument.Load(resxFile);

var result = from item in xDoc.Descendants("data")
select new
{
    Name = item.Attribute("name").Value,
    Value = item.Element("value").Value
};

foreach (var entry in result)
{
    string name = entry.Name;
    string value = entry.Value;
    //Do somethign here
}

THe problem is that when I get to my foreach loop I get an exception or: "An unhandled exception of type 'System.NullReferenceException' occurred in MyProgram.exe. Object reference not set to an instance of an object"

Does anyone know why?? Am I using the LINQ correctly

Upvotes: 1

Views: 884

Answers (1)

Sergey Berezovskiy
Sergey Berezovskiy

Reputation: 236188

Looks like some data element do not have name attribute or value element. To avoid this - use casting instead of accessing Value property. Otherwise you will receive NullReferenceException if either name attribute or value element is not found

var result = from item in xDoc.Descendants("data")
             select new {
                 Name = (string)item.Attribute("name"),
                 Value = (string)item.Element("value")
             };

Another possible reason is namespace issue. But default resource files do no have namespaces defined.

Upvotes: 2

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