如何将AppiumDriver焦点更改为出现在不同图层上的下拉列表？iOS

// 导入所需的类
import io.appium.java_client.AppiumDriver;
import io.appium.java_client.MobileElement;
import io.appium.java_client.ios.IOSDriver;
import io.appium.java_client.remote.MobileCapabilityType;
import org.openqa.selenium.remote.DesiredCapabilities;

// 设置DesiredCapabilities
DesiredCapabilities caps = new DesiredCapabilities();
caps.setCapability(MobileCapabilityType.PLATFORM_NAME, "iOS");
caps.setCapability(MobileCapabilityType.DEVICE_NAME, "iPhone Simulator");
caps.setCapability(MobileCapabilityType.APP, "path/to/your/app");

// 创建AppiumDriver对象
AppiumDriver<MobileElement> driver = new IOSDriver<>(new URL("http://localhost:4723/wd/hub"), caps);

// 找到包含下拉列表的元素并点击
MobileElement dropdownElement = driver.findElement(By.id("dropdownElementId"));
dropdownElement.click();

// 切换焦点到下拉列表所在的图层
driver.switchTo().activeElement();

// 在下拉列表中找到选项并选择
MobileElement optionElement = driver.findElement(By.id("optionElementId"));
optionElement.click();