Nullreferenceexception using Htmlagilitypack

Question

I wonder how many tags <a> exist within a div, but the Exception NullReferenceException is fired when arriving on Xpath.

var baseURL = "AQUI VAI A MINHA URL";

var client = new HtmlWeb();

var pagina = client.Load(baseURL);

var quantidade = pagina.DocumentNode.SelectNodes("//*[@id='react - root']/section/main/article/div/div[1]/div[1]/a").Count;

He couldn’t get in the way or I’m doing something wrong?

Answer 1

The method SelectNodes() returns a null if it does not find any node that meets the specified one. Then the code tries to catch the count and generates this error. But you may have some previous error to generate the null improperly. This should solve:

var nos = pagina.DocumentNode.SelectNodes("//*[@id='react - root']/section/main/article/div/div[1]/div[1]/a");
var quantidade = nos == null ? 0 : nos.Count;

I put in the Github for future reference.