List Exception: Object Null reference

[Samishii23]

I'm having a issue with my List<string> variables... When I run the following code... Errors out on the ***** line of code... I commented out the Try block to have the editor show me the line of code that was giving me the runtime error, as the try/catch wasn't telling me enough information.

public void Load_ClassData(string c) {
	// Global Data Class init
	CGlobalData gd = new CGlobalData();
	gd.Talent = new List<string>();
	gd.Discription = new List<string>();
	// To Load new Data. Must reset old data
	// URI = InstallFolder / Version Folder / Using Version / Class Name / .xml
	// Later will be replaced with GetClassVersion()
	string uri = _settings[18] + "/wowv/" + "[3.2.2]" + c + ".xml";
	//try  {
		XDocument doc = XDocument.Load(uri);
		//gd.TreeBG = doc.Root.Descendants().Where(x => x.Name == "Class").First().Attribute("bg").Value;
		//gd.TreeIco = doc.Root.Descendants().Where(x => x.Name == "Class").First().Attribute("treeico").Value;
		var qTalent = from x in doc.Root.Descendants()
			where x.Name == "Talent"
			select x;
		var qDisc = from z in doc.Root.Descendants()
			where z.Name == "disc"
			select z;

		foreach (XElement x in qTalent) {
			// <Talent> Parsing
			if (Int32.Parse(x.Attribute("pts").Value) > 0) {
				// If <Talent> Has another talent requirement attribute
				// Data = ID / Points / Title / Icon / Requirement (if has one)
				if (x.LastAttribute.Name == "req") { gd.Talent.Add(x.Attribute("id").Value + "," + x.Attribute("pts").Value + "," + x.Attribute("title").Value + "," + x.Attribute("icon").Value + "," + x.Attribute("req").Value); }
				else { gd.Talent.Add(x.Attribute("id").Value + "," + x.Attribute("pts").Value + "," + x.Attribute("title").Value + "," + x.Attribute("icon").Value); }
				// Write descripition
				// If Talent Points is over 1
				// Data = Replace String / Description paragraph
				***** if (Int32.Parse(x.Attribute("pts").Value) > 1) { gd.Discription.Add(x.Descendants().First().Attribute("replace").Value + "]|[" + x.Descendants().First().Value); }
				else { gd.Discription.Add(x.Descendants().First().Value); }
			}
			else
			{
				// If Talent is "Empty", has 0 points, no description
				gd.Talent.Add(x.Attribute("id").Value + "," + x.Attribute("pts").Value);
				gd.Discription.Add("none");
			}
		}
	//} catch (Exception EX) { MessageBox.Show("Error: " + EX.Message); }
}

public class CGlobalData {
	// Current Class
	public int SelectedClass { get; set; }
	// This holds the Tree BG data
	public string TreeBG { get; set; }
	// This holds Tree Icon data
	public string TreeIco { get; set; }
	// This holds the actual data for each Talent: (id,title,icon,req*)
	public List<string> Talent;
	// This holds the Talent discription: [Replace Strings]
	public List<string> Discription;
}

Object reference not set to an instance of an object.

Any ideas?

[tlhintoq]

"How do I fix a 'object reference not set to an instance of an object' error?

The line your code stopped on while debugging holds all your answers.
One of the variables/objects was created but not initialized. For example:

string TempString;// Created but not initialized so this is still null
//versus
string TempString = string.empty;

Debug your project again. This time, when it breaks on a line look at the Locals pallet to see which variable/object is null. You can also hover your mouse over each variable and the hothelp will shows its value. One of them will be null.

[Samishii23]

I looked at the Locals list while debugging.

I added

gd.Discription = new List<string>();
gd.Talent = new List<string>();
gd.Discription.Clear();
gd.Talent.Clear();

just below the gd Init. The .Clear()'s don't error out, though they did before I added the Inits for the lists.

In the de-bug with the error on screen, these are the values:

Discription	Count = 0x00000039	System.Collections.Generic.List<string>
Talent	Count = 0x0000003a	System.Collections.Generic.List<string>

When I open of the + for them, each list has 0x39h items in the list... And its still talking about Null reference... Aw crap... That means the Linq variables has a null... Ugh


Edit: Thanks for telling me about the Local variables list thing. It helped me solve the problem.