如何设计实现无缝轮播

类别：react / 日期：2023-05-04 / 浏览：666 / 评论：0

贴一段轮播的核心代码：

// scroll the notice
useEffect(() => {
  const requestAnimationFrame =
    window.requestAnimationFrame ||
    window.webkitRequestAnimationFrame ||
    window.mozRequestAnimationFrame;
  const cancelAnimationFrame =
    window.cancelAnimationFrame ||
    window.webkitCancelAnimationFrame ||
    window.mozCancelAnimationFrame;
  const scrollNode = noticeContentEl.current;
  const distance = scrollNode.clientWidth / 2;
  scrollNode.style.left = scrollNode.style.left || 0;
  window.__offset = window.__offset || 0;
  let requestId = null;
  const scrollLeft = () => {
    const speed = 0.5;
    window.__offset = window.__offset + speed;
    scrollNode.style.left = -window.__offset + "px";
    // 关键行：当距离小于偏移量时，重置偏移量
    if (distance <= window.__offset) window.__offset = 0;
    requestId = requestAnimationFrame(scrollLeft);
  };
  requestId = requestAnimationFrame(scrollLeft);
  if (pause) cancelAnimationFrame(requestId);
  return () => cancelAnimationFrame(requestId);
}, [notice, pause]);