代码仅解析第一个<div> </div>子项

Question

我在主<div></div>节点中有3个孩子<div class="RecentTrades"></div>。但我的代码只解析了第一个孩子（即标题，即日期，时间等）。在调试时，第一轮是好的（cols到cols8似乎有值），但是当代码for (int i = 0; i < rows.Count; ++i)运行第二轮时，cols到cols8变为null。任何帮助将非常感激！谢谢！

<div></div>：

<div class="RecentTrades">
    <div class="TradesRow TradesHeader">
        <div class="TradesDate">Date</div>
        <div class="TradesTime">Time</div>
        <div class="TradesPrice">Trade Prc</div>
        <div class="TradesVolume">Volume</div>
        <div class="TradesBuySell">Buy/Sell</div>
        <div class="TradesBid">Bid</div>
        <div class="TradesAsk">Ask</div>
        <div class="TradesValue">Value</div>
    </div>
    <div class="TradesRow TradesBG_G" style="color:#ff0000;">
        <div class="TradesDate">08-Jan-14</div>
        <div class="TradesTime">17:05:00</div>
        <div class="TradesPrice">83.80</div>
        <div class="TradesVolume">1,970,861</div>
        <div class="TradesBuySell">Sell*&nbsp;</div>
        <div class="TradesBid">83.85</div>
        <div class="TradesAsk">83.88</div>
        <div class="TradesValue">1.652<strong>M</strong></div>
    </div>
    <div class="TradesRow TradesBG_W" style="color:#ff0000;">
        <div class="TradesDate">07-Jan-14</div>
        <div class="TradesTime">16:30:11</div>
        <div class="TradesPrice">80.739</div>
        <div class="TradesVolume">40,000</div>
        <div class="TradesBuySell">Sell*&nbsp;</div>
        <div class="TradesBid">83.85</div>
        <div class="TradesAsk">83.88</div>
        <div class="TradesValue">32.30<strong>k</strong></div>
    </div>
</div>

我的代码：

// Load HTML
HtmlAgilityPack.HtmlDocument doc = new HtmlAgilityPack.HtmlDocument();
doc.Load(fileName);
// Get specific node in the document
HtmlNode node = doc.DocumentNode.SelectSingleNode("//div[@class='RecentTrades']"); 

using (FileStream fs = new FileStream(@"..\..\bin\Debug\ModifiedPages\" + "RecentShareTrades.txt", FileMode.Append))
using (StreamWriter sw = new StreamWriter(fs))
{
      // Iterate all rows in the relevant div
      HtmlNodeCollection rows = node.SelectNodes(".//div");
      for (int i = 0; i < rows.Count; ++i)
      {
           // Iterate all columns in this row
           HtmlNodeCollection cols = rows[i].SelectNodes(".//div[@class='TradesDate']");
           HtmlNodeCollection cols2 = rows[i].SelectNodes(".//div[@class='TradesTime']");
           HtmlNodeCollection cols3 = rows[i].SelectNodes(".//div[@class='TradesPrice']");
           HtmlNodeCollection cols4 = rows[i].SelectNodes(".//div[@class='TradesVolume']");
           HtmlNodeCollection cols5 = rows[i].SelectNodes(".//div[@class='TradesBuySell']");
           HtmlNodeCollection cols6 = rows[i].SelectNodes(".//div[@class='TradesBid']");
           HtmlNodeCollection cols7 = rows[i].SelectNodes(".//div[@class='TradesAsk']");
           HtmlNodeCollection cols8 = rows[i].SelectNodes(".//div[@class='TradesValue']");

           for (int j = 0; j < cols.Count; ++j)
           // Get the value of the column and print it
           sw.WriteLine(cols[j].InnerText + "," + cols2[j].InnerText + "," + cols3[j].InnerText + "," + cols4[j].InnerText.Replace(",", "") + "," + cols5[j].InnerText + "," + cols6[j].InnerText + "," + cols7[j].InnerText + "," + cols8[j].InnerText + "," + row.Cells[0].Value.ToString());
       }
       sw.Flush();
       sw.Close();
       fs.Close();
 }