如何通过向下滚动显示内容？

Question

我为我的网页编写了一些 html 代码，其中显示了多个图像。问题是，所有图像都是在开始时加载的。我想通过向下滚动来更改它以显示额外的图像。如何用 jQuery 做到这一点？

代码是：

    {% extends "base.html" %}
{% load staticfiles %}

{% block content %}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="container">
      <h2>Pictures of Coffee</h2>
      <div class="row">
        <div class="col-lg-4 col-xs-6 thumbnail"><img src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/04LDEYRW59.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/90V03Q5Y60.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/O83SF2RB6D.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/5JVPSVP7EI.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/C5Y10KIIHA.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/YSSFRY5B25.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/04LDEYRW59.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/90V03Q5Y60.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/O83SF2RB6D.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/5JVPSVP7EI.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/C5Y10KIIHA.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/YSSFRY5B25.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/04LDEYRW59.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/90V03Q5Y60.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/O83SF2RB6D.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/5JVPSVP7EI.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/C5Y10KIIHA.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/YSSFRY5B25.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/04LDEYRW59.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/90V03Q5Y60.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/O83SF2RB6D.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/5JVPSVP7EI.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/C5Y10KIIHA.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/YSSFRY5B25.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/04LDEYRW59.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/90V03Q5Y60.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/O83SF2RB6D.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/5JVPSVP7EI.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/C5Y10KIIHA.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/YSSFRY5B25.jpg" alt=""></div>
      </div>

    </div>
{% endblock %}

我只想添加 javascript，以便在向下滚动页面时加载图像。我尝试了 codepen 网站上的代码，但它正在工作。如何解决？

Answer 1

这会有所帮助:)

运行代码 sn -p 并检查。

当您继续滚动页面时，如果窗口滚动位置大于最后一个图像滚动位置，屏幕上剩余的图像将被显示。

function showImages(){
    
  var imgStartIndex = 0;
  var nextSetOfImages = 10;
  var incrementImageLimit = 10;
  var collectionOfImages = $(".thumbnail img");
  var noOfImages = collectionOfImages.length;

  return function(){
  
    for (var i = imgStartIndex; i < nextSetOfImages; i++){
      $(collectionOfImages[i]).fadeIn().addClass("shown");
    } 

    imgStartIndex = imgStartIndex + incrementImageLimit;
    nextSetOfImages = imgStartIndex + nextSetOfImages;
    nextSetOfImages = (nextSetOfImages >= noOfImages) ? noOfImages : nextSetOfImages;

  };
    
}

var disImg = showImages();

$(document).ready(function(){
  disImg();
  
  $(document).scroll(function(){
    
    var scollPostion = $(window).scrollTop();
    var imgShownLast = $(".thumbnail img.shown").last();
    var imgShowFist = $(".thumbnail img.shown").first();
    var imgLastScrollPos = $(imgShownLast).offset().top;
    var imgFirstScrollPos = $(imgShowFist).offset().top;
    scollPostion = scollPostion + imgFirstScrollPos + 200; 
    if(scollPostion > imgLastScrollPos){ 
      disImg();
    }
    
  });
  
});

.thumbnail img{
  width:100px;
  height:100px;
  display:none;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<div class="container">
      <h2>Pictures of Coffee</h2>
      <div class="row">
        <div class="col-lg-4 col-xs-6 thumbnail"><img src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/04LDEYRW59.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/90V03Q5Y60.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/O83SF2RB6D.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/5JVPSVP7EI.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/C5Y10KIIHA.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/YSSFRY5B25.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/04LDEYRW59.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/90V03Q5Y60.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/O83SF2RB6D.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/5JVPSVP7EI.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/C5Y10KIIHA.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/YSSFRY5B25.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/04LDEYRW59.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/90V03Q5Y60.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/O83SF2RB6D.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/5JVPSVP7EI.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/C5Y10KIIHA.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/YSSFRY5B25.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/04LDEYRW59.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/90V03Q5Y60.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/O83SF2RB6D.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/5JVPSVP7EI.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/C5Y10KIIHA.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/YSSFRY5B25.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/04LDEYRW59.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/90V03Q5Y60.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/O83SF2RB6D.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/5JVPSVP7EI.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/C5Y10KIIHA.jpg" alt=""></div>
        <div class="col-lg-4 col-xs-6 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/YSSFRY5B25.jpg" alt=""></div>
      </div>

    </div>

Answer 2

滚动事件是：

$(window).on('scroll', function() {

 //write your logics to load your images as per requirements

})

Answer 3

首先引导程序将一行分成 12 列，例如：

<div class="container">
        <div class="row">
             <div class="col-xs-4 col-lg-4 thumbnail"><img src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/04LDEYRW59.jpg" alt=""></div>
             <div class="col-xs-4 col-lg-4 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/90V03Q5Y60.jpg" alt=""></div>
             <div class="col-xs-4 col-lg-4 thumbnail"><img  src="https://d2lm6fxwu08ot6.cloudfront.net/img-thumbs/960w/O83SF2RB6D.jpg" alt=""></div>
        </div>
</div>

使用具有上述列的另一行（在容器中）。要制作滚动效果，您需要三个组件： Animate ccs https://daneden.github.io/animate.css/ viewportchecker https://github.com/dirkgroenen/jQuery-viewport-checker jquery http://code.jquery.com/jquery.js
按照此示例将其添加到 html 模板的标记头中。在哪里找到 href 或 src 必须用上面三个文件的存储路径覆盖，或者直接使用外部文件，例如http://code.jquery.com/jquery.js

<link rel="stylesheet" type="text/css" href="animate.css" />
<script src="viewportchecker.js"></script>
<script src="http://code.jquery.com/jquery.js"></script>
<style>
    .hidden{opacity:0;}
    .visible{opacity:1;}
</style>

在body标签中添加这个，用你的代码替换容器但记住脚本将效果添加到“.post”类所以也许你会想要更改你的代码类的名称，或者你也可以在脚本：

<div class="container">
            <div class="post"> <!-- Post content goes here --> </div>
            <div class="post"> <!-- Post content goes here --> </div>
            <div class="post"> <!-- Post content goes here --> </div>
            <div class="post"> <!-- Post content goes here --> </div>
            <div class="post"> <!-- Post content goes here --> </div>
            <div class="post"> <!-- Post content goes here --> </div>
</div>