Dexters Dexters - 3 months ago 8
C# Question

Unable to read XML correctly

I found an article to help with XML parsing:
http://geekswithblogs.net/pabothu/archive/2014/04/29/reading-a-complex-xml-using-linq-in-c-sharp.aspx.

I am trying to read the XML but I am getting a null object. I am a bit confused what I am doing wrong since I am not able to debug into those LINQ queries.

var containers =
from container in xmlDoc.Descendants("container")
//where container.Attribute("ID").Value != "0"
select new Container
{
id = Convert.ToInt32(container.Element("id").Value),
name = container.Element("name").Value,
enabled = Convert.ToBoolean(container.Element("enabled").Value),
components = new List<Component>(
from component in container.Descendants("component")
select new Component
{
id = Convert.ToInt32(component.Element("id").Value),
name = component.Element("name").Value,
type = component.Element("type").Value,
connectors = new List<Connector>(
from connector in component.Descendants("connector")
select new Connector
{
id = Convert.ToInt32(component.Element("id").Value),
name = connector.Element("name").Value,
source = connector.Element("id").Value,
destination = component.Element("id").Value
})
})
};


And here is the XML:

<?xml version="1.0" encoding="UTF-8"?>
<simplevisio>
<container>
<id>1</id>
<name>Naming</name>
<component>
<id>2</id>
<type>Server</type>
<name>First</name>
<connector>
<id>3</id>
<name>.</name>
</connector>
<connector>
<id>5</id>
<name>isShortName()</name>
</connector>
</component>
<component>
<id>3</id>
<type>Server</type>
<name>Last</name>
<connector>
<id>5</id>
<name>isShortName()</name>
</connector>
</component>
<enable>true</enable>
<connector>
<id>5</id>
<name>getFullname()</name>
</connector>
</container>
<container>
<id>4</id>
<name></name>
<component>
<id>5</id>
<type>Server</type>
<name>FirstLast</name>
</component>
<enable>false</enable>
</container>
</simplevisio>

Answer

You're querying for enabled elements, but your sample XML contains enable elements. That's why you're getting NullReferenceException.

Change

enabled = Convert.ToBoolean(container.Element("enabled").Value),

to

enabled = Convert.ToBoolean(container.Element("enable").Value),

or update your XML schema to match your query.