Parsing Html select elements in Web Page using C#

Step 1: download and add reference of Html Agility Pack to your project
Download Html Agility Pack from the following link:

http://htmlagilitypack.codeplex.com/

Add a reference of the library to your project

Step 2: download the html web page to parse

Use the following code to download the web page.

private void Download(string url)
{
    WebClient client = new WebClient();

    client.DownloadFileCompleted +=    new AsyncCompletedEventHandler(client_DownloadFileCompleted);

    client.DownloadFileAsync(new Uri(url), @"c:\temp.html");
 }

void client_DownloadFileCompleted(object sender, AsyncCompletedEventArgs e)
{
    //do something here
}

Step 3: Parse the downloaded web page using Html Agility Pack

Use the following code in the client_DownloadFileCompleted() to enumerate all links in the web page.

void client_DownloadFileCompleted(object sender, AsyncCompletedEventArgs e)
{
 Dictionary<string, string> search_foods=new Dictionary<string, string>();
 HtmlAgilityPack.HtmlDocument doc = new HtmlAgilityPack.HtmlDocument();
 HtmlNode.ElementsFlags.Remove("option");
 doc.Load("c:\\temp.html", Encoding.UTF8);

 HtmlNodeCollection select_node_collection = doc.DocumentNode.SelectNodes("//select[@name='SearchFood']//option");
 if (select_node_collection != null)
 {
  foreach (HtmlNode node in select_node_collection)
  {
   string option_value = node.Attributes["value"].Value;
   string option_text = node.InnerText;
   search_foods[option_text] = option_value;
  }
 }
}