最近我一直在 flex slider 中实现延迟加载。我使用 flex slider 的 after 事件延迟加载图像。我观察到，如果快速按下箭头图标并且幻灯片快速移动，则不会触发 after 事件。这是一个演示:
$('#carousel').flexslider({
animation: "slide",
controlNav: false,
animationLoop: false,
slideshow: false,
itemWidth: 210,
itemMargin: 5,
asNavFor: '#slider',
after: function(slider) {
console.log("after fired on " + slider.currentSlide);
//$("#flex-carousel-H img").slice( ((slider.currentSlide + 1)*4), (((slider.currentSlide + 2)*4) + 1)).each(flexLazy);
}
});
$('#slider').flexslider({
animation: "slide",
controlNav: false,
animationLoop: false,
slideshow: false,
sync: "#carousel"
});<script src="https://code.jquery.com/jquery-2.1.4.min.js"></script>
<link href="https://cdnjs.cloudflare.com/ajax/libs/flexslider/2.6.3/flexslider.min.css" rel="stylesheet" />
<script src="https://cdnjs.cloudflare.com/ajax/libs/flexslider/2.6.3/jquery.flexslider.min.js"></script>
<!-- Place somewhere in the <body> of your page -->
<div id="slider" class="flexslider">
<ul class="slides">
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<!-- items mirrored twice, total of 12 -->
</ul>
</div>
<div id="carousel" class="flexslider">
<ul class="slides">
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
<li>
<img src="http://flexslider.woothemes.com/images/kitchen_adventurer_cheesecake_brownie.jpg" />
</li>
</ul>
</div>请尝试单击底部缩略图 slider 中的向右箭头图标。您会发现控制台不会记录每张幻灯片。但是，如果我们缓慢地点击，那么每张幻灯片的控制台日志。
问题:
1. 如果幻灯片快速移动，为什么不为每张幻灯片触发 after 事件。
2. 即使幻灯片快速移动，如何强制 after 触发。
谢谢
最佳答案
不确定您是否已经找到了答案，但我遇到了同样的问题，而不是使用动画结束时触发的 after 回调，您应该使用 before回调。它会在动画开始“之前”触发，并且无论您以多快的速度浏览幻灯片，它都会始终触发。
关于javascript - 如果快速移动幻灯片，为什么 Flex slider 事件后不触发？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/41360860/