当你有多个页面需要向下滚动时，如何在Appium上向下滚动？

import io.appium.java_client.TouchAction;
import io.appium.java_client.touch.WaitOptions;
import io.appium.java_client.touch.offset.PointOption;
import java.time.Duration;

TouchAction touchAction = new TouchAction(driver);

int screenWidth = driver.manage().window().getSize().getWidth();
int screenHeight = driver.manage().window().getSize().getHeight();

int startX = screenWidth / 2; // 屏幕宽度的一半
int startY = (int) (screenHeight * 0.8); // 屏幕高度的80%
int endX = startX;
int endY = (int) (screenHeight * 0.2); // 屏幕高度的20%

touchAction.press(PointOption.point(startX, startY))
           .waitAction(WaitOptions.waitOptions(Duration.ofMillis(1000))) // 等待1秒
           .moveTo(PointOption.point(endX, endY))
           .release()
           .perform();