Question

我正在尝试使用Html Agility Pack获取“Transaction and get url”的全部价值。当我使用谷歌检查HTML源时，我能够看到带有网址的完整交易ID。我的问题是如何获得所有Transaction的完整值以及与它们关联的url，并将它们添加到我的数据网格中使用Async。由于Windows商店应用程序不支持，我无法使用“SelectNode”。##标题##

这是网站的网址：http://explorer.litecoin.net/address/LeDGemnpqQjrK8v1s5HZKaDgjgDKQ2MYiK

async private void GetTransactions()
{
    url = "http://explorer.litecoin.net/address/LeDGemnpqQjrK8v1s5HZKaDgjgDKQ2MYiK";
    string html;

    HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
    try
    {
        WebResponse x = await req.GetResponseAsync();
        HttpWebResponse res = (HttpWebResponse)x;
        if (res != null)
        {
            if (res.StatusCode == HttpStatusCode.OK)
            {
                Stream stream = res.GetResponseStream();
                using (StreamReader reader = new StreamReader(stream))
                {
                    html = reader.ReadToEnd();
                }
                HtmlDocument htmlDocument = new HtmlDocument();
                htmlDocument.LoadHtml(html);

               var tsTable = htmlDocument.DocumentNode.ChildNodes["html"].ChildNodes["body"].ChildNodes["div"].
                        ChildNodes["div"].ChildNodes["div"].ChildNodes["table"].InnerHtml;

                    int n = 2;
                    var tsRow = tsTable.Split(Environment.NewLine.ToCharArray()).Skip(n).ToArray();

                    for (var index = 1; index < tsRow.Count(); index++)
                    {

                    }
            }
        }
    }
    catch
    {
        MessageDialog messageDialog =
            new MessageDialog("A tear occured in the space-time continuum. Please try again when all planets in the solar system are aligned.");
    }
}

<telerikGrid:RadDataGrid Grid.RowSpan="1"  ItemsSource="{Binding Data}" IsSynchronizedWithCurrentItem="True" AlternateRowBackground="AliceBlue" Background="White" Grid.Row="2" 
                         UserEditMode="Inline" UserGroupMode="Disabled" VerticalAlignment="Bottom" AutoGenerateColumns="False" Height="294" Grid.ColumnSpan="2">
    <telerikGrid:RadDataGrid.GroupDescriptors>
        <telerikGrid:PropertyGroupDescriptor PropertyName="Group"/>
    </telerikGrid:RadDataGrid.GroupDescriptors>
    <telerikGrid:RadDataGrid.Columns>
        <telerikGrid:DataGridNumericalColumn PropertyName="Id" CanUserEdit="False" CanUserFilter="False" Header="#" SizeMode="Fixed" Width="40"/>
        <telerikGrid:DataGridTextColumn PropertyName="pnDate" CanUserFilter="False" Header="Date" CellContentFormat="{}{0,0:dd.MM.yyyy}"/>
        <telerikGrid:DataGridNumericalColumn PropertyName="pnType" CanUserFilter="False" Header="Type"/>
        <telerikGrid:DataGridTextColumn PropertyName="pnAddress" CanUserFilter="False" Header="Address"/>
        <telerikGrid:DataGridDateColumn PropertyName="pnAmount" CanUserFilter="False" Header="Amount"/>
    </telerikGrid:RadDataGrid.Columns>
</telerikGrid:RadDataGrid>

Answer 1

SelectNode（带有XPath查询）只是自己迭代遍历节点并进行匹配。您只需手动执行此操作，查看HTML本身并构建路径以获得所需内容。

var table = htmlDocument.DocumentNode.ChildNodes["html"].ChildNodes["Body"].ChildNodes[0].ChildNodes[0].ChildNodes[0].ChildNodes["Table"];

现在您已经拥有了表（并且您可以更具体地使用ChildNodes，例如查找具有特定类属性值的Div），您可以开始查看行。第一行是标题，我们不关心它。

// The first table row is index 0 and looks like this:
// <tr><th>Transaction</th><th>Block</th><th>Approx. Time</th><th>Amount</th><th>Balance</th><th>Currency</th></tr>
// It is the column headers, each <th> node represents a column. The foreach below starts at index 1, the first row of real data...
foreach(var index = 1; index < table.ChildNodes.Count; index++)
{
    // a row of data looks like:
    // <tr><td><a href="../tx/513.cut for space.b4a#o1">5130f066e0...</a></td><td><a href="../block/c3.cut for space.c9c">468275</a></td><td>2013-11-28 09:14:17</td><td>0.3</td><td>0.3</td><td>LTC</td></tr>
    // each <td> node inside of the row, is the matching data for the column index...
    var row = table.ChildNodes[index];
    var transactionLink = row.ChildNodes[0].ChildNodes["a"].Attributes["href"].Value;
    var transactionText = row.ChildNodes[0].ChildNodes["a"].InnerText;

    // Other variables for the table row data... 
    // Here is one more example
    var apporxTime = row.ChildNodes[2].InnerText;
}

Answer 2

这是一个黑客的地狱，但如果您绝对肯定不使用@the_lotus提到的API，您可以尝试使用以下正则表达式进行解析。

\<td\>\s*\<a(?:.*)href="(?<url>[^"]*)"\>(?<block>[^<]*)\</a\>\s*\</td\>\s*\<td\>(?<date>[^<]*)\</td\>\s*\<td\>(?<amount>[^<]*)\</td\>\s*\<td\>(?<balance>[^<]*)\</td\>\s*\<td\>(?<currency>[^<]*)\</td\>

使用Html Agility Pack从网页中的表中获取值而不使用“SelectNode”

2 个答案: