如何使用 jQuery 将 class 添加到柱状图？

Question

如何在用户将鼠标悬停在栏上时向栏中添加 class？我部署了如下代码，但没有得到正确的输出。

例如在CSS中，我们添加类似“.bar:hover:before”的代码，我如何在jQuery中添加.bar:hover:before？

$(function() {
  $("#bars li .bar").each(function(key, bar) {
    var percentage = $(this).data('percentage');

    $(this).css('height', percentage + '%');

    $(this).animate({
      'height': percentage + '%'
    }, 1000);
  });
});


$(window).load(function() {
  $('.bar').prepend('class="lnr lnr-star"');

})

#chart {
  width: 650px;
  height: 300px;
  margin: 30px auto 0;
  display: block;
}
#chart #numbers {
  width: 50px;
  height: 100%;
  margin: 0;
  padding: 0;
  display: inline-block;
  float: left;
}
#chart #numbers li {
  text-align: right;
  padding-right: 1em;
  list-style: none;
  height: 29px;
  border-bottom: 1px solid #444;
  position: relative;
  bottom: 30px;
}
#chart #numbers li:last-child {
  height: 30px;
}
#chart #numbers li span {
  color: #eee;
  position: absolute;
  bottom: 0;
  right: 10px;
}
#chart #bars {
  display: inline-block;
  background: rgba(0, 0, 0, 0.2);
  width: 600px;
  height: 300px;
  padding: 0;
  margin: 0;
  box-shadow: 0 0 0 1px #444;
}
#chart #bars li {
  display: table-cell;
  width: 100px;
  height: 300px;
  margin: 0;
  text-align: center;
  position: relative;
}
#chart #bars li .bar {
  display: block;
  width: 70px;
  margin-left: 15px;
  background: #49E;
  position: absolute;
  bottom: 0;
  height: 0;
  -webkit-transition: height 1s ease-in-out;
  -moz-transition: height 1s ease-in-out;
  -o-transition: height 1s ease-in-out;
  transition: height 1s ease-in-out;
}
#chart #bars li .bar:hover {
  background: #5AE;
  cursor: pointer;
}
#chart #bars li .bar:hover:before {
  color: white;
  content: "\e814" attr(data-percentage);
  position: relative;
  bottom: 20px;
}
#chart #bars li span {
  color: #eee;
  width: 100%;
  position: absolute;
  bottom: -2em;
  left: 0;
  text-align: center;
}
.lnr.lnr-star {
  font-size: 13px;
  margin-right: 1px;
  color: yellow;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
<link href="https://cdn.linearicons.com/free/1.0.0/icon-font.min.css" rel="stylesheet" />

<div id="chart">

  <ul id="bars">
    <li>
      <div data-percentage="56" class="bar"></div><span><i class="lnr lnr-star"></i></span>
    </li>
  </ul>
</div>

Answer 1

使用 jQuery，您将使用 .addClass() method. So what you would do instead of prepending it. You would do this: $('.bar').addClass('lnr lnr-star'); Prepending items doesn't add it inside the tag, it puts it as another item before the object selected. When calling a function when the user hovers over an object, you would use the .hover() 方法。使用 HTML，您已经有了图标，您可以删除它的类，因为 jQuery 会将类添加到图标。所以你将拥有：

$(function() {
  $("#bars li .bar").each(function(key, bar) {
    var percentage = $(this).data('percentage');

    $(this).css('height', percentage + '%');

    $(this).animate({
      'height': percentage + '%'
    }, 1000);
  });
});


$('.bar').hover(function() {
  $('.bar-icon').addClass('lnr lnr-star');
}, function() {
  $('.bar-icon').removeClass('lnr lnr-star');
});

#chart {
  width: 650px;
  height: 300px;
  margin: 30px auto 0;
  display: block;
}
#chart #numbers {
  width: 50px;
  height: 100%;
  margin: 0;
  padding: 0;
  display: inline-block;
  float: left;
}
#chart #numbers li {
  text-align: right;
  padding-right: 1em;
  list-style: none;
  height: 29px;
  border-bottom: 1px solid #444;
  position: relative;
  bottom: 30px;
}
#chart #numbers li:last-child {
  height: 30px;
}
#chart #numbers li span {
  color: #eee;
  position: absolute;
  bottom: 0;
  right: 10px;
}
#chart #bars {
  display: inline-block;
  background: rgba(0, 0, 0, 0.2);
  width: 600px;
  height: 300px;
  padding: 0;
  margin: 0;
  box-shadow: 0 0 0 1px #444;
}
#chart #bars li {
  display: table-cell;
  width: 100px;
  height: 300px;
  margin: 0;
  text-align: center;
  position: relative;
}
#chart #bars li .bar {
  display: block;
  width: 70px;
  margin-left: 15px;
  background: #49E;
  position: absolute;
  bottom: 0;
  height: 0;
  -webkit-transition: height 1s ease-in-out;
  -moz-transition: height 1s ease-in-out;
  -o-transition: height 1s ease-in-out;
  transition: height 1s ease-in-out;
}
#chart #bars li .bar:hover {
  background: #5AE;
  cursor: pointer;
}
#chart #bars li .bar:hover:before {
  color: white;
  content: "\e814" attr(data-percentage);
  position: relative;
  bottom: 20px;
}
#chart #bars li span {
  color: #eee;
  width: 100%;
  position: absolute;
  bottom: -2em;
  left: 0;
  text-align: center;
}
.lnr.lnr-star {
  font-size: 13px;
  margin-right: 1px;
  color: yellow;
}

<link href="https://cdn.linearicons.com/free/1.0.0/icon-font.min.css" rel="stylesheet" />
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>

<div id="chart">

  <ul id="bars">
    <li>
      <div data-percentage="56" class="bar">
        <i></i> 
      </div>
    </li>
  </ul>
</div>

如何使用 jQuery 将 class 添加到柱状图？

How to add a class to a bar using jQuery?

javascript

jquery

css

jquery-hover