在从另一个循环派生的循环中打印某些内容时遇到问题

Question

我创建了一个 vba 脚本来解析定义为 postTime 的不同帖子的时间以及来自网页的标题。虽然postTime 在目标页面中可用，但我想从登录页面获取它并使用从目标页面收集的postTitle 打印它。我在我的脚本中定义了能够收集所需内容的选择器。但是，我当前的尝试只打印了某个帖子的postTime 几次，而我想打印多个帖子的postTime。

如何在从另一个循环派生的循环中打印项目？

到目前为止我的脚本：

Sub CollectData()
    Const baseUrl = "https://stackoverflow.com"
    Dim Http As New XMLHTTP60, Html As New HTMLDocument
    Dim post As Object, itemlist$, linklist As Variant
    Dim qualifiedLink$, nlink As Variant, postTime$, postTitle$

    With Http
        .Open "GET", "https://stackoverflow.com/questions/tagged/web-scraping", False
        .send
        Html.body.innerHTML = .responseText
    End With

    Set post = Html.querySelectorAll(".summary .question-hyperlink")

    For I = 0 To post.Length - 1
        postTime = Html.querySelector(".user-action-time").innerText
        qualifiedLink = baseUrl & Split(post(I).getAttribute("href"), "about:")(1)
        itemlist = itemlist & IIf(itemlist = "", "", " ") & qualifiedLink
    Next I

    linklist = Split(itemlist, " ")

    For Each nlink In linklist
        With Http
            .Open "GET", nlink, False
            .send
            Html.body.innerHTML = .responseText
        End With
        postTitle = Html.querySelector("h1[itemprop='name'] a").innerText
        ' the following line prints postTime derived from earlier loop
        Debug.Print postTime, postTitle
    Next nlink
End Sub

Answer 1

您需要在第一个循环期间使用 querySelectorAll 并对其进行索引，以确保您获得不同的发布时间。我会将这些存储在一个集合中，并通过索引访问它们 最后一个循环

Option Explicit

Public Sub CollectData()
    Const baseUrl = "https://stackoverflow.com"
    Dim Http As New XMLHTTP60, Html As New HTMLDocument
    Dim post As Object, itemlist$, linklist As Variant, i As Long
    Dim qualifiedLink$, nlink As Variant, postTime$, postTitle$
    Dim times As Object
    Set times = New Collection
    With Http
        .Open "GET", "https://stackoverflow.com/questions/tagged/web-scraping", False
        .send
        Html.body.innerHTML = .responseText
    End With

    Set post = Html.querySelectorAll(".summary .question-hyperlink")

    For i = 0 To post.Length - 1
        postTime = Html.querySelectorAll(".user-action-time").item(i).innerText
        times.Add postTime
        qualifiedLink = baseUrl & Split(post(i).getAttribute("href"), "about:")(1)
        itemlist = itemlist & IIf(itemlist = "", "", " ") & qualifiedLink
    Next i

    linklist = Split(itemlist, " ")
    Dim accessor As Long
    For Each nlink In linklist
        accessor = accessor + 1
        With Http
            .Open "GET", nlink, False
            .send
            Html.body.innerHTML = .responseText
        End With
        postTitle = Html.querySelector("h1[itemprop='name'] a").innerText
        ' the following line prints postTime derived from earlier loop
        Debug.Print times(accessor), postTitle

    Next nlink
End Sub

---

更好的是，将时间存储在一个变量中，而不是在循环中继续使用querySelectorAll，因为这样会更有效：

Option Explicit

Public Sub CollectData()
    Const baseUrl = "https://stackoverflow.com"
    Dim Http As New XMLHTTP60, Html As New HTMLDocument
    Dim post As Object, itemlist$, linklist As Variant, i As Long
    Dim qualifiedLink$, nlink As Variant, postTime$, postTitle$
    Dim times As Object
    Set times = New Collection
    With Http
        .Open "GET", "https://stackoverflow.com/questions/tagged/web-scraping", False
        .send
        Html.body.innerHTML = .responseText
    End With

    Set post = Html.querySelectorAll(".summary .question-hyperlink")
    Dim timesList As Object
    Set timesList = Html.querySelectorAll(".user-action-time")
    For i = 0 To post.Length - 1
        postTime = timesList.item(i).innerText
        times.Add postTime
        qualifiedLink = baseUrl & Split(post(i).getAttribute("href"), "about:")(1)
        itemlist = itemlist & IIf(itemlist = "", "", " ") & qualifiedLink
    Next i

    linklist = Split(itemlist, " ")
    Dim accessor As Long
    For Each nlink In linklist
        accessor = accessor + 1
        With Http
            .Open "GET", nlink, False
            .send
            Html.body.innerHTML = .responseText
        End With
        postTitle = Html.querySelector("h1[itemprop='name'] a").innerText
        ' the following line prints postTime derived from earlier loop
        Debug.Print times(accessor), postTitle

    Next nlink
End Sub