HTML Agility pack: parsing an href tag

2019-01-27 13:59发布

问题:

How would I effectively parse the href attribute value from this :

<tr>
<td rowspan="1" colspan="1">7</td>
<td rowspan="1" colspan="1">
<a class="undMe" href="/ice/player.htm?id=8475179" rel="skaterLinkData" shape="rect">D. Kulikov</a>
</td>
<td rowspan="1" colspan="1">D</td>
<td rowspan="1" colspan="1">0</td>
<td rowspan="1" colspan="1">0</td>
<td rowspan="1" colspan="1">0</td>
[...]

I am interested in having the player id, which is: 8475179 Here is the code I have so far:

        // Iterate all rows (players)
        for (int i = 1; i < rows.Count; ++i)
        {
            HtmlNodeCollection cols = rows[i].SelectNodes(".//td");

            // new player
            Dim_Player player = new Dim_Player();

                // Iterate all columns in this row
                for (int j = 1; j < 6; ++j)
                {
                    switch (j) {
                        case 1: player.Name = cols[j].InnerText;
                                player.Player_id = Int32.Parse(/* this is where I want to parse the href value */); 
                                break;
                        case 2: player.Position = cols[j].InnerText; break;
                        case 3: stats.Goals = Int32.Parse(cols[j].InnerText); break;
                        case 4: stats.Assists = Int32.Parse(cols[j].InnerText); break;
                        case 5: stats.Points = Int32.Parse(cols[j].InnerText); break;
                    }
                }

回答1:

Based on your example this worked for me:

HtmlDocument htmlDoc = new HtmlDocument();
htmlDoc.Load("test.html");
var link = htmlDoc.DocumentNode
                  .Descendants("a")
                  .First(x => x.Attributes["class"] != null 
                           && x.Attributes["class"].Value == "undMe");

string hrefValue = link.Attributes["href"].Value;
long playerId = Convert.ToInt64(hrefValue.Split('=')[1]);

For real use you need to add error checking etc.



回答2:

Use an XPath expression to find it:

 foreach (HtmlNode link in doc.DocumentNode.SelectNodes("//a[@class='undMe']"))
 {
      HtmlAttribute att = link.Attributes["href"];
      Console.WriteLine(new Regex(@"(?<=[\?&]id=)\d+(?=\&|\#|$)").Match(att.Value).Value);
 }