向下滚动时隐藏标题/向上滚动时显示

Question

我的这个脚本工作得几乎很好，但是由于某种原因，当向上滚动时，标题会在一秒钟后重新出现。为什么？我想不通。

这是我的例子https://jsfiddle.net/wg8zv95f/

这里是原脚本http://jsfiddle.net/mariusc23/s6mLJ/31/

$(document).ready(function() {

  var didScroll;
  var lastScrollTop = 0;
  var delta = 5;
  var headerContainer = $('#header');
  var navbarHeight = headerContainer.outerHeight();

  $(window).scroll(function(event) {
    didScroll = true;
  });

  setInterval(function() {
    if (didScroll) {
      hasScrolled();
      didScroll = false;
    }
  }, 250);


  function hasScrolled() {
    var st = $(this).scrollTop();

    // Make sure they scroll more than delta
    if (Math.abs(lastScrollTop - st) <= delta)
      return;

    // If they scrolled down and are past the navbar, add class .nav-up.
    // This is necessary so you never see what is "behind" the navbar.
    if (st > lastScrollTop && st > navbarHeight) {
      // Scroll Down
      headerContainer.removeClass('slideInDown').addClass('fadeOutUp');
    } else {
      // Scroll Up
      if (st + $(window).height() < $(document).height()) {
        headerContainer.removeClass('fadeOutUp').addClass('slideInDown');
      }
    }

    lastScrollTop = st;
  }


});

CSS

header {
  position: fixed;
  width: 100%;
  animation-duration: 0.8s;
  z-index: 99999;
}

Answer 1

headerContainer.removeClass('slideInDown').addClass('fadeOutUp').slideUp();
headerContainer.removeClass('fadeOutUp').addClass('slideInDown').slideDown();

将此添加到您的脚本中

.slideInDown {
    animation-name: slideInDown;
}
.fadeOutUp {
    animation-name: fadeOutUp;
}

删除此样式