Question

I’m trying to remove all elements that have attribute value that doesn’t start with specific text

Thanks to Jon Skeet I got the first part however some elements doesn’t contain this attribute, therefore I got NullReferenceExpection with the message: “Object reference not set to an instance of an object”

I added an extra check for null value but it still doesn’t work any idea?

elements =(from el in xmlFile.Root.Elements(elementName)
where ( !el.Attribute(attributeName).Value.Equals(DBNull.Value)
&& !el.Attribute(attributeName).Value.StartsWith(searchBeforeStar))
select el);

Answer 1

You have to test if your node contains the attribute before testing it.

Add el.Attribute(attributeName) != null :

elements =(from el in xmlFile.Root.Elements(elementName) 
           where ( el.Attribute(attributeName) != null
                && !el.Attribute(attributeName).Value.Equals(DBNull.Value) 
                && !el.Attribute(attributeName).Value.StartsWith(searchBeforeStar))
           select el);