Linq to Xml: reading from XML null reference exception

Asked May 11 '17 at 06:47

Active May 11 '17 at 06:47

Viewed 26 times

I am trying to use Xml.Linq to read from an Xml I previously created by Xml.Linq. This is how XML looks like:

 <ItemsCollection>
  <Item>
    <ItemName>Computer</ItemName>
    <ItemDescription>Computer's description</ItemDescription>
    <ItemCategory>Electronics</ItemCategory>
    <ItemPrice>2499.99</ItemPrice>
  </Item>
</ItemsCollection>

Code responsible for parsing those elements into Item class objects is this:

 var res = from myItem in xdoc.Root.Elements("Item")
                      select new Item((string)myItem.Element("ItemName"), (string)myItem.Element("ItemDescription"),
                      (Category)Enum.Parse(typeof(Category), (string)myItem.Element("ItemCategory")), (double)myItem.Element("Price"));

When being executed, linq expression throws NullReferenceException.

asked May 11 '17 at 06:47

wis.niowy

can you also post definition of `Category`? – Lei Yang May 11 '17 at 06:50
Try : (double?). If double is null you need the question mark. – jdweng May 11 '17 at 06:57
@jdweng (double?) cast is incorrect - "cannot convert `double?` to `double`" – wis.niowy May 11 '17 at 07:13
@[Lei Yang] `Category` is just enum type with three values: `Clothes`, `Electronics` and `Food` – wis.niowy May 11 '17 at 07:14
The the class Item constructor parameter list must also be made double?. – jdweng May 11 '17 at 08:09
1

Your query should be for the element `ItemPrice`, not `Price`. There is no element called `Price`, hence the result is `null`. – Charles Mager May 11 '17 at 08:10

Linq to Xml: reading from XML null reference exception

0 Answers0