HtmlAgilityPack Youtube search in UWP c#

Use WebView instead of HtmlWeb to get the HTML

WebView webView = new WebView();
webView.Navigate(new Uri(@"https://www.youtube.com/results?search_query=cado+dalle+nubi+trailer+ita"));

private async void WebView_NavigationCompletedAsync(WebView sender, WebViewNavigationCompletedEventArgs args)
{
    var siteHtML = await webView.InvokeScriptAsync("eval", new string[] { "document.documentElement.innerHTML;" });
}

The first video was in the second index. So use SelectNodes and select the second index

HtmlDocument htmlDoc = web.Load(siteHtML );
string result = htmlDoc.DocumentNode.SelectNodes("//div/div/div/div/h3/a")[1].OuterHtml;

Here is the final code

WebView webView = new WebView();

public void GetFirstVideo(string UrlString)
{
    webView.Navigate(new Uri(UrlString));
    webView.NavigationCompleted -= WebView_NavigationCompletedAsync;  //To avoid multiple subscribe
    webView.NavigationCompleted += WebView_NavigationCompletedAsync;
}

private async void WebView_NavigationCompletedAsync(WebView sender, WebViewNavigationCompletedEventArgs args)
{
    webView.NavigationCompleted -= WebView_NavigationCompletedAsync;  //To stop if there is any re-direct
    var siteHtML = await webView.InvokeScriptAsync("eval", new string[] { "document.documentElement.innerHTML;" });
    var htmlDocument = new HtmlDocument();
    htmlDocument.LoadHtml(siteHtML);
    var firstVideoTitle = htmlDocument.DocumentNode.SelectNodes("//div/div/div/div/h3/a")[1].OuterHtml;
}