为什么单选按钮大小（）在硒中显示0？

Question

WebDriver driver = new FirefoxDriver(); 
driver.get("http://www.w3schools.com/html/tryit.asp?filename=tryhtml_radio"); 
List<WebElement> radio_buttons = driver.findElements(By.name("gender")); 
System.out.println(radio_buttons.size()); 

Answer 1

这些元素在<iframe id="iframeResult" frameborder="0">之内。您需要先切换至iframe：

WebDriver driver = new FirefoxDriver(); 
driver.get("http://www.w3schools.com/html/tryit.asp?filename=tryhtml_radio"); 

WebDriverWait wait = new WebDriverWait(driver,10); 
wait.until(ExpectedConditions.frameToBeAvailableAndSwitchToIt(By.id("iframeResult"))); 

List<WebElement> radio_buttons = driver.findElements(By.name("gender")); 
System.out.println(radio_buttons.size());