网页抓取：运行-time error 91 Object variable not set

Question

我正在尝试使用来自该网站的信息更新我的物种数据库：https://www.afcd.gov.hk/english/conservation/hkbiodiversity/database/search.php

我有一个包含 A 列物种列表的 xlsm，并在网站的搜索引擎中搜索它们中的每一个，这导致一个页面显示 link 到另一个专用于该特定的页面物种。每个物种都有一个唯一的ID标识，这就是我要的信息。

例如如果我在搜索框“学名”中输入“Mnais mneme”，将出现一个显示 table 的页面，其中包含该物种，其名称附有 link (https://www.afcd.gov.hk/english/conservation/hkbiodiversity/database/popup_record.php?id=781&lang=en)。 “781”将是物种 ID。

我想将此 link 复制到我的 xlsm 的 B 列中，并在 Excel 中提取 ID：

Sub SearchBot()
 
    'dimension (declare or set aside memory for) our variables
    Dim objIE As InternetExplorer 'special object variable representing the IE browser
    
    'link will be the <a> carrying the href with the species id
    Dim link As HTMLAnchorElement
              
    'define y as interger counter
    Dim y As Integer
               
    'initiating a new instance of Internet Explorer and assigning it to objIE
    Set objIE = New InternetExplorer
 
    'make IE browser visible (False would allow IE to run in the background)
    objIE.Visible = True
 
    'navigate IE to this web page
    objIE.navigate "https://www.afcd.gov.hk/english/conservation/hkbiodiversity/database/search.php"
 
    'wait here for a few seconds while the browser is busy
    Do While objIE.Busy = True Or objIE.readyState <> 4: DoEvents: Loop
    
    objIE.document.getElementById("s1").Click
 
    'in the search box put cell "A2" value
    objIE.document.all.Item("scientific_name").Value = Sheets("Sheet1").Range("A2").Value
 
    'click the 'Search' button
    objIE.document.getElementsByClassName("btn_3")(1).Click
    
    'wait again for the browser
    Do While objIE.Busy = True Or objIE.readyState <> 4: DoEvents: Loop
    
    'select the species name link
    Set link = objIE.document.getElementsByTagName("td")(4).getElementsByTagName ("a")(0)
                
    y = 2
        
    'print the link to column B in Sheet1
    Sheets("Sheet1").Range("B" & y).Value = link.href
    
End Sub

调试显示

run-time error 91

在最后一行停止时：

Sheets("Sheet1").Range("B" & y).Value = link.href

设置link为HTMLAnchorElement有问题吗？我尝试将其设置为对象，但错误仍然出现。

Answer 1

下面是一些使用网络请求查找您感兴趣的数据的代码。我查看了页面，发现复选框也包含 SpeciesID，因此，我使用了名称该控件找到输入的值。

代码

Public Function GetSpeciesID(ScientificName As String) As String
    Dim requestURL      As String
    Const InvalidValue  As String = "-1"
    
    'If the Scientific Name is blank, return a default value
    If (Trim$(ScientificName) = vbNullString) Then
        GetSpeciesID = InvalidValue
        Exit Function
    End If
    
    requestURL = "https://www.afcd.gov.hk/english/conservation/hkbiodiversity/database/doSearch.php?" & _
    "entity_id=0&family_name=&scientific_name=" & WorksheetFunction.EncodeURL(ScientificName) & _
    "&common_name=&chinese_name=&hk_protection_status_val=&chinared_status_val=&iucn_status_val="
    
    With CreateObject("MSXML2.ServerXMLHTTP.6.0")
        .Open "GET", requestURL
        .send
        
        Dim html As Object: Set html = CreateObject("htmlfile")
        html.body.innerhtml = .responseText
    End With
    
    GetSpeciesID = html.getElementsByName("check")(0).Value
End Function

'Run this method
Public Sub Runner()
    Debug.Print GetSpeciesID("Mnais mneme")
End Sub

网页抓取：运行-time error 91 Object variable not set

Web scraping: Run-time error 91 Object variable not set

html

excel

vba

runtime-error

web-scraping