目录导航随页面滚动 about markdown-navbar HOT 1 OPEN

const NAVBAR_MIDDLE = 250;

const onScroll = () => {
    const activeItem = document.querySelector(".active");
    if (activeItem) {
        const offsetTop = activeItem.offsetTop;
        const navbar = document.querySelector(".markdown-navigation ");
        if (offsetTop > NAVBAR_MIDDLE) {
            navbar.scrollTop = offsetTop - NAVBAR_MIDDLE;
        } else {
            navbar.scrollTop = 0;
        }
    }
}

useEffect(() => {
    window.addEventListener("scroll", onScroll)
    return () => {
        window.removeEventListener("scroll", onScroll)
    }
}, [])