问题
How can I navigate a dynamic drop down list via " using = 'id' " (e.g., remDr$findElement(using='id', value="main_ddYear") ?
I can find and click using findElement. After clicking I could send "down arrow" keys (keystrokes) and an "enter" if I know how many arrows down my targeted selection is.
Sample of the page source
<select name="main$ddYear" onchange="javascript:setTimeout('__doPostBack(\'main$ddYear\',\'\')', 0)" id="main_ddYear" class="groupTextBox">
<option selected="selected" value="2017">2017</option>
<option value="2016">2016</option>
<option value="2015">2015</option>
<option value="2014">2014</option>
<option value="2013">2013</option>
</select>
I would like to do something similar to the solution in this post but with 'id' instead of 'xpath' . I could not adapt the xpath solution.
Another solution in Java used a "Select" class which I did not find referenced in the quick start tutorial or documentation.
I will post a separate question about how to scrape the drop down list of options / values.
回答1:
With a little knowledge about XPath, adapting the linked solution which using XPath for your case should be straightforward, for example :
option <- remDr$findElement(using = 'xpath', "//select[@id='main_ddYear']/option[@value='2014']")
option$clickElement()
Brief explanation about the XPath :
//select[@id='main_ddYear']: Find<select>element, anywhere in the HTML, whereidattribute value equals'main_ddYear'/option[@value = '2014']: From such<select>element, return child<option>wherevalueattribute value equals'2014'.
来源：https://stackoverflow.com/questions/39713466/r-rselenium-navigate-drop-down-menu-list-box-using-id