配合js做监听
  const scrollListener = () => {
    const topHeight = getScrollTop();
    if (topHeight === 0) {
      scrollIsTop.value = true;
    } else {
      scrollIsTop.value = false;
    }
    scrollLeft.value =
      Math.max(document.body.scrollLeft, document.documentElement.scrollLeft) +
      "px";
  };
  onMounted(() => {
    window.addEventListener("scroll", scrollListener);
  });
  onUnmounted(() => {
    window.removeEventListener("scroll", scrollListener);
  });
  scrollListener();