VBA 将 ie 元素传递给函数

Question

由于我在可靠地检查 ie.busy 和 ie.readystate 以检查网页是否已加载时遇到困难，我有一个函数可以检查是否存在特定元素以确认页面已加载。

下面的代码有效，但很笨拙，因为我必须为我调用的每个要检查的页面设置一个单独的函数。理想情况下，我想将行 "ie.document.getElementsByClassName("container centered-form single-column clearfix")(0).innerText" 作为参数传递给函数，以便该函数可用于任何网页，但我不能弄清楚如何做到这一点。

非常感谢

Function checkLoginUrl(ie As Variant, strMessageContent As String, compareString As String) As Boolean

        EndTime = Now + TimeValue("00:00:22")
        Application.Wait (Now + TimeValue("00:00:01")) 'wait a bit to start with as code falls here as too quick

        'get the value of the element we are monitoring
        dd = ie.document.getElementsByClassName("container centered-form single-column clearfix")(0).innerText

        Do While dd = ""
            DoEvents
            'recheck the value we are monitoring
            dd = ie.document.getElementsByClassName("container centered-form single-column clearfix")(0).innerText
            Printlog (Now & " - " & dd & " - and waited 3 secs")
            Application.Wait (Now + TimeValue("00:00:03"))
            If StartTime > EndTime Then
                Printlog ("Tried to log on for 22 seconds without success")
            Exit Do
            End If
        Loop

        'so dd should be populated now so check
        If dd Like "*" & compareString & "*" Then

            Printlog (strMessageContent & " loaded successfully")

            retval = True
        Else
            Printlog (strMessageContent & " failed to load")
            retval = False

        End If

    launchUrl = retval

End Function

Answer 1

您是否可以将 ie.document.getElementsByClassName("container centered-form single-column clearfix")(0).innerText 的值存储在变量中并将字符串参数传递给您的通过在函数中添加一个字符串参数来实现功能，如下所示？

Function checkLoginUrl(ie As Variant, strMessageContent As String, compareString As String, element as string) As Boolean

如果我对您的上述描述有任何误解，请告诉我。我会努力改正自己的。

Answer 2

也许熟悉一下 css selectors，您可以在其中指定模式以将节点与字符串匹配，然后将其传递给函数。简单一点的功能为好，并确保您使用的是一致的命名方式。目前，由于结束赋值变量具有不同的名称，您不会从函数返回。为了获得更大的灵活性，还将等待时间作为参数传递。

直接的优点是您无需担心所有不同的链接方法 (getElementsBy...)，并且您使用的是现代浏览器优化的方法。

Option Explicit
Public Sub test()
    Dim ie As New InternetExplorer, url As String, result As Boolean
    Dim strMessageContent As String, compareString As String
    Const MAX_WAIT_SEC As Long = 10

    url = "https://example.com"

    With ie
        .Visible = True
        .Navigate2 "url"

        While .Busy Or .readyState < 4: DoEvents: Wend

        cssSelector = ".container.centered-form.single-column.clearfix"

        result = checkLoginUrl(ie, cssSelector, strMessageContent, compareString, MAX_WAIT_SEC) 'you might consider renaming 'result' as 'found' _
                               and move the final If statement out the function and have it following here ......

        Stop
        .Quit
    End With
End Sub

Public Function checkLoginUrl(ByVal ie As Object, ByVal cssSelector As String, ByVal strMessageContent As String, compareString As String, ByVal MAX_WAIT_SEC As Long) As Boolean
    Dim t As Date, ele As Object, dd As String, found As Boolean

    t = Timer
    Do
        On Error Resume Next
        Set ele = ie.document.querySelector(cssSelector)
        dd = ele.innerText
        found = InStr(dd, compareString) > 0
        On Error GoTo 0
        If Timer - t > MAX_WAIT_SEC Then Exit Do
    Loop Until found

    If found Then
        Printlog strMessageContent & " loaded successfully"
    Else
        Printlog "Tried to log on for " & MAX_WAIT_SEC & " seconds without success"
        Printlog strMessageContent & " failed to load"
    End If
    checkLoginUrl = found
End Function

VBA 将 ie 元素传递给函数

VBA pass ie element to a function

excel

internet-explorer

automation

vba

web-scraping