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Excel VBA HTML嵌套查询选择器

css-selectors web-scraping vba excel html

2

drec4s · 技术社区 · 7 年前

考虑HTML页面的这个摘录:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
</head>
<body>
<div class="BoxBody">
<span class="txt">20 Records found. </span>
<p style="text-align: right;"><span class="txt">[First/Previous] &nbsp;1&nbsp;, <a class="page" href="javascript:paginacao('paginar','2');" title="Go to page 2">2</a> [<a class="page" title="Next page" href="javascript:paginacao('paginar','next');">Next</a>/<a class="page" title="Last page" href="javascript:paginacao('paginar','last');">Last</a>]</span></p>
<br>
<span class="txt">25 Records found. </span>
<p style="text-align: right;"><span class="txt">[First/Previous] &nbsp;1&nbsp;, <a class="page" href="javascript:paginacao('paginar2','2');" title="Go to page 2">2</a> [<a class="page" title="Next page" href="javascript:paginacao('paginar2','next');">Next</a>/<a class="page" title="Last page" href="javascript:paginacao('paginar2','last');">Last</a>]</span></p>
</div>
</body>
</html>

我在试着得到 anchor 具有“下一页”的标记 href (如果有)。

我使用Firefox在控制台中尝试了这个方法,效果很好:

document.querySelector(".BoxBody > p:nth-child(2) > span:nth-child(1)").querySelector("a[title='Next page']")

querySelector 同样,但它失败了 Invalid argument .

Sub test()

Dim oFSO As Object, paginator As Object
Dim oFS As Object, sText As String

Set oFSO = CreateObject("Scripting.FileSystemObject")
Set oFS = oFSO.OpenTextFile(ThisWorkbook.Path & "\example.html")

Do Until oFS.AtEndOfStream
    sText = oFS.ReadAll()
Loop


Dim html As HTMLDocument, html2 As Object
Set html = New HTMLDocument
Set html2 = html
html2.Write sText

Set paginator = html.querySelector(".BoxBody > p:nth-child(2) > span:nth-child(1)").querySelector("a[title='Next page']")

End Sub

是什么原因造成的?这个 p:nth-child(2) 标识符? 如何使用VBA提取该元素?

1 回复 | 直到 7 年前

1

4

QHarr 5 年前

nth-child(2) VBA中不支持,并且确实导致错误消息。你不能使用 :nth-child() 或 :nth-of-type() . 在可用于处理伪类的库中实现的很少。你可以用 first-child 有趣的是。您还将发现,可以链接querySelector的对象有限。

Dim ele As Object, iText As String
Set ele = html.querySelector(".BoxBody > p > span:first-child > a[title='Next page']")
   
On Error Resume Next
iText = ele.href
On Error GoTo 0

If iText = vbNullString Then '<== This assumes that the href has a value otherwise use an On Error GoTo which will then handle the error and print "no href"
    Debug.Print "No href"
Else
   Debug.Print "href"
End If

编辑:29/5/21从上个月的某个时候开始(?)可以广泛使用element.querySelector以及大多数标准的伪类选择器(至少对于Windows 10,MSHTML.DLL 11.00.19041.985(日期修改于12/5/21)