NullReferenceException в HtmlAgilityPack
Я пытаюсь извлечьlink
с помощьюxpath
из нижеуказанного URL
<code>string url = "http://www.album-cover-art.org/search.php?q=Ruin+-+Live+Album+Version+Lamb+of+God" </code>
Мой код:
<code>HtmlAgilityPack.HtmlWeb web = new HtmlAgilityPack.HtmlWeb(); HtmlAgilityPack.HtmlDocument htmlDoc = new HtmlAgilityPack.HtmlDocument(); htmlDoc = web.Load(url); //Exception generated here Line 23 if (htmlDoc.DocumentNode != null) { HtmlNode linkNode = htmlDoc.DocumentNode.SelectSingleNode(".//*[@id='related_search_row']/img/@src"); if (linkNode != null) Console.WriteLine(linkNode.InnerText); } </code>
Код выше компилируется нормально, но когда я пытаюсь запустить, он генерирует исключение
<code>Unhandled Exception: System.NullReferenceException: Object reference not set to an instance of an object. </code>
Полная трассировка стека
<code>System.NullReferenceException: Object reference not set to an instance of an object. at HtmlAgilityPack.HtmlDocument.ReadDocumentEncoding(HtmlNode node) in C:\Source\htmlagilitypack\Trunk\HtmlAgilityPack\HtmlDocument.cs:line 1916 at HtmlAgilityPack.HtmlDocument.PushNodeEnd(Int32 index, Boolean close) in C:\Source\htmlagilitypack\Trunk\HtmlAgilityPack\HtmlDocument.cs:line 1805 at HtmlAgilityPack.HtmlDocument.Parse() in C:\Source\htmlagilitypack\Trunk\HtmlAgilityPack\HtmlDocument.cs:line 1468 at HtmlAgilityPack.HtmlDocument.Load(TextReader reader) in C:\Source\htmlagilitypack\Trunk\HtmlAgilityPack\HtmlDocument.cs:line 769 at HtmlAgilityPack.HtmlWeb.Get(Uri uri, String method, String path, HtmlDocument doc, IWebProxy proxy, ICredentials creds) in C:\Source\htmlagilitypack\Trunk\HtmlAgilityPack\HtmlWeb.cs:line 1515 at HtmlAgilityPack.HtmlWeb.LoadUrl(Uri uri, String method, WebProxy proxy, NetworkCredential creds) in C:\Source\htmlagilitypack\Trunk\HtmlAgilityPack\HtmlWeb.cs:line 1563 at HtmlAgilityPack.HtmlWeb.Load(String url, String method) in C:\Source\htmlagilitypack\Trunk\HtmlAgilityPack\HtmlWeb.cs:line 1149 at HtmlAgilityPack.HtmlWeb.Load(String url) in C:\Source\htmlagilitypack\Trunk\HtmlAgilityPack\HtmlWeb.cs:line 1107 at ScreenScrapping.Program.Main(String[] args) in c:\Users\ranveer\csharp\ScreenScrapping\ScreenScrapping\Program.cs:line 23 </code>
Итак, мой вопрос, почему я получаю это исключение.