我正在开发各种网络爬虫,可以从各种网站中提取物品的价格。我遇到的问题是,在amazon.com上,对于有多个选项(即大小)的项目,我能够进行交互,并更改下拉选择选项,但我无法让网站进行回发和显示该选项的具体价格。我意识到这不是一个不常见的问题,但大多数人似乎通过使用.dispatchEvent方法而不是.fireEvent解决了他们的问题。这似乎对我不起作用。
下拉选项(仅显示前5个):
<option value="-1" id="native_size_name_-1" data-a-id="size_name_-1" selected=""> Select</option>
<option value="0,B001249LAS" class="dropdownAvailable" data-a-css-class="dropdownAvailable" id="native_size_name_0" data-a-id="size_name_0" data-a-html-content="44W x 29L">
44W x 29L
</option>
<option value="1,B001249KAE" class="dropdownAvailable" data-a-css-class="dropdownAvailable" id="native_size_name_1" data-a-id="size_name_1" data-a-html-content="44W x 30L">
44W x 30L
</option>
<option value="2,B001243XPM" class="dropdownAvailable" data-a-css-class="dropdownAvailable" id="native_size_name_2" data-a-id="size_name_2" data-a-html-content="44W x 32L">
44W x 32L
</option>
<option value="3,B001243XRK" class="dropdownAvailable" data-a-css-class="dropdownAvailable" id="native_size_name_3" data-a-id="size_name_3" data-a-html-content="44W x 34L">
44W x 34L
</option>
<option value="4,B001243Z00" class="dropdownAvailable" data-a-css-class="dropdownAvailable" id="native_size_name_4" data-a-id="size_name_4" data-a-html-content="46W x 29L">
46W x 29L
</option>
<option value="5,B001245XG4" class="dropdownAvailable" data-a-css-class="dropdownAvailable" id="native_size_name_5" data-a-id="size_name_5" data-a-html-content="46W x 30L">
46W x 30L
</option>
</select><span style="min-width: 0%;" tabindex="-1" id="dropdown_selected_size_name" data-a-class="aui-variation a-fastclick-disable" class="a-button a-button-dropdown aui-variation a-fastclick-disable"><span class="a-button-inner"><span class="a-button-text a-declarative" data-action="a-dropdown-button" aria-haspopup="true" role="button" tabindex="0"><span class="a-dropdown-prompt"> Select</span></span><i class="a-icon a-icon-dropdown"></i></span></span></span>
Firefox向我显示与下拉列表相关的事件:
"native_dropdown_selected_size_name").onchange = function() {
TwisterNonJs.handleDropDown[0]();
这是我的代码,Excel似乎编译.dispatchEvent方法就好了,但IE在启动时不会触发。
URLPath = http://www.amazon.com/Lee-Big-Tall-Dungarees-Carpenter-Original/dp/B001243Z00/ elementid =“priceblock_ourprice”(带引号)
Sub getPrice(URLPath As String, elementid As String)
Set IE = CreateObject("internetexplorer.application")
IE.Visible = True
navigate:
IE.navigate URLPath
Do While IE.readystate <> 4: DoEvents: Loop
Set doc = CreateObject("htmlfile")
Set doc = IE.document
If doc Is Nothing Then GoTo navigate
doc.getElementById("native_dropdown_selected_size_name").Focus
doc.getElementById("native_dropdown_selected_size_name").SelectedIndex = 2
Dim objEvent
Set objEvent = doc.createEvent("HTMLEvents")
objEvent.initEvent "change", False, True
doc.getElementById("native_dropdown_selected_size_name").dispatchEvent objEvent
Do While IE.readystate <> 4: DoEvents: Loop
pricestr = doc.getElementById(elementid).innertext