用户看到技能栏时动画入门

Question

我的问题是，我只学习js和jquery，我只是练习如何制作技能栏。

然后我在这里找到了一些不错的代码： CodePen

然后我尝试将代码放到我的本地主机网站上，并且动画效果非常好。

但是我的问题是，我想在用户向下滚动并查看技能栏时使动画开始

这是代码：

jQuery(document).ready(function(){
	jQuery('.skillbar').each(function(){
		jQuery(this).find('.skillbar-bar').animate({
			width:jQuery(this).attr('data-percent')
		},6000);
	});
});

body {
  font-family: 'Ubuntu', sans-serif;
  width:960px;
}

p{
  color:#525252;
  font-size:12px;
}

.skillbar {
	position:relative;
	display:block;
	margin-bottom:15px;
	width:100%;
	background:#eee;
	height:35px;
	border-radius:3px;
	-moz-border-radius:3px;
	-webkit-border-radius:3px;
	-webkit-transition:0.4s linear;
	-moz-transition:0.4s linear;
	-ms-transition:0.4s linear;
	-o-transition:0.4s linear;
	transition:0.4s linear;
	-webkit-transition-property:width, background-color;
	-moz-transition-property:width, background-color;
	-ms-transition-property:width, background-color;
	-o-transition-property:width, background-color;
	transition-property:width, background-color;
}

.skillbar-title {
	position:absolute;
	top:0;
	left:0;
width:110px;
	font-weight:bold;
	font-size:13px;
	color:#ffffff;
	background:#6adcfa;
	-webkit-border-top-left-radius:3px;
	-webkit-border-bottom-left-radius:4px;
	-moz-border-radius-topleft:3px;
	-moz-border-radius-bottomleft:3px;
	border-top-left-radius:3px;
	border-bottom-left-radius:3px;
}

.skillbar-title span {
	display:block;
	background:rgba(0, 0, 0, 0.1);
	padding:0 20px;
	height:35px;
	line-height:35px;
	-webkit-border-top-left-radius:3px;
	-webkit-border-bottom-left-radius:3px;
	-moz-border-radius-topleft:3px;
	-moz-border-radius-bottomleft:3px;
	border-top-left-radius:3px;
	border-bottom-left-radius:3px;
}

.skillbar-bar {
	height:35px;
	width:0px;
	background:#6adcfa;
	border-radius:3px;
	-moz-border-radius:3px;
	-webkit-border-radius:3px;
}

.skill-bar-percent {
	position:absolute;
	right:10px;
	top:0;
	font-size:11px;
	height:35px;
	line-height:35px;
	color:#ffffff;
	color:rgba(0, 0, 0, 0.4);
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<h1>jQuery & CSS3 Skills Bar</h1>

<div class="skillbar clearfix " data-percent="20%">
	<div class="skillbar-title" style="background: #d35400;"><span>HTML5</span></div>
	<div class="skillbar-bar" style="background: #e67e22;"></div>
	<div class="skill-bar-percent">20%</div>
</div> <!-- End Skill Bar -->

<div class="skillbar clearfix " data-percent="25%">
	<div class="skillbar-title" style="background: #2980b9;"><span>CSS3</span></div>
	<div class="skillbar-bar" style="background: #3498db;"></div>
	<div class="skill-bar-percent">25%</div>
</div> <!-- End Skill Bar -->

<div class="skillbar clearfix " data-percent="50%">
	<div class="skillbar-title" style="background: #2c3e50;"><span>jQuery</span></div>
	<div class="skillbar-bar" style="background: #2c3e50;"></div>
	<div class="skill-bar-percent">50%</div>
</div> <!-- End Skill Bar -->

<div class="skillbar clearfix " data-percent="40%">
	<div class="skillbar-title" style="background: #46465e;"><span>PHP</span></div>
	<div class="skillbar-bar" style="background: #5a68a5;"></div>
	<div class="skill-bar-percent">40%</div>
</div> <!-- End Skill Bar -->

<div class="skillbar clearfix " data-percent="75%">
	<div class="skillbar-title" style="background: #333333;"><span>Wordpress</span></div>
	<div class="skillbar-bar" style="background: #525252;"></div>
	<div class="skill-bar-percent">75%</div>
</div> <!-- End Skill Bar -->

<div class="skillbar clearfix " data-percent="100%">
	<div class="skillbar-title" style="background: #27ae60;"><span>SEO</span></div>
	<div class="skillbar-bar" style="background: #2ecc71;"></div>
	<div class="skill-bar-percent">100%</div>
</div> <!-- End Skill Bar -->

<div class="skillbar clearfix " data-percent="70%">
	<div class="skillbar-title" style="background: #124e8c;"><span>Photoshop</span></div>
	<div class="skillbar-bar" style="background: #4288d0;"></div>
	<div class="skill-bar-percent">70%</div>
</div> <!-- End Skill Bar -->

<p><strong>SOURCE :</strong> http://w3lessons.info/2013/06/04/skill-bar-with-jquery-css3/</p>

Answer 1

您快到了。要以滚动方式显示动画，您要做的就是检查element是否在视口中，以便用户立即看到它。您可以使用一些第三方库或小型jQuery代码段来实现。我已经更新了您的代码，以检查进度条是否在视口中，然后进行动画处理。检查代码注释。

// Function to check if given element is completely in viewport or not
// source : https://medium.com/talk-like/detecting-if-an-element-is-in-the-viewport-jquery-a6a4405a3ea2

$.fn.isFullyInViewport = function() {
  var elementTop = $(this).offset().top;
  var elementBottom = elementTop + $(this).outerHeight();

  var viewportTop = $(window).scrollTop();
  var viewportBottom = viewportTop + $(window).height();

  return elementTop >= viewportTop && elementBottom <= viewportBottom;
};
jQuery(document).ready(function(){
  // on page ready check if element is already in viewport
  animateProgressBar();
});

$(window).on('resize scroll', function() {
  // on page resize or scroll check if element is in viewport
  animateProgressBar();
});


// if elemnt is visble in viewport , then animate
var animateProgressBar = function(){
    $('.skillbar').each(function() {
     if ($(this).isFullyInViewport()) {
     	jQuery(this).find('.skillbar-bar').animate({
			width:jQuery(this).attr('data-percent')
		},600);
     }
  }); 
}

body {
  font-family: 'Ubuntu', sans-serif;
  width:960px;
}

p{
  color:#525252;
  font-size:12px;
}

.skillbar {
	position:relative;
	display:block;
	margin-bottom:15px;
	width:100%;
	background:#eee;
	height:35px;
	border-radius:3px;
	-moz-border-radius:3px;
	-webkit-border-radius:3px;
	-webkit-transition:0.4s linear;
	-moz-transition:0.4s linear;
	-ms-transition:0.4s linear;
	-o-transition:0.4s linear;
	transition:0.4s linear;
	-webkit-transition-property:width, background-color;
	-moz-transition-property:width, background-color;
	-ms-transition-property:width, background-color;
	-o-transition-property:width, background-color;
	transition-property:width, background-color;
}

.skillbar-title {
	position:absolute;
	top:0;
	left:0;
width:110px;
	font-weight:bold;
	font-size:13px;
	color:#ffffff;
	background:#6adcfa;
	-webkit-border-top-left-radius:3px;
	-webkit-border-bottom-left-radius:4px;
	-moz-border-radius-topleft:3px;
	-moz-border-radius-bottomleft:3px;
	border-top-left-radius:3px;
	border-bottom-left-radius:3px;
}

.skillbar-title span {
	display:block;
	background:rgba(0, 0, 0, 0.1);
	padding:0 20px;
	height:35px;
	line-height:35px;
	-webkit-border-top-left-radius:3px;
	-webkit-border-bottom-left-radius:3px;
	-moz-border-radius-topleft:3px;
	-moz-border-radius-bottomleft:3px;
	border-top-left-radius:3px;
	border-bottom-left-radius:3px;
}

.skillbar-bar {
	height:35px;
	width:0px;
	background:#6adcfa;
	border-radius:3px;
	-moz-border-radius:3px;
	-webkit-border-radius:3px;
}

.skill-bar-percent {
	position:absolute;
	right:10px;
	top:0;
	font-size:11px;
	height:35px;
	line-height:35px;
	color:#ffffff;
	color:rgba(0, 0, 0, 0.4);
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<h1>jQuery & CSS3 Skills Bar</h1>
<div style="margin-bottom:600px;"></div>
<div class="skillbar clearfix " data-percent="20%">
	<div class="skillbar-title" style="background: #d35400;"><span>HTML5</span></div>
	<div class="skillbar-bar" style="background: #e67e22;"></div>
	<div class="skill-bar-percent">20%</div>
</div> <!-- End Skill Bar -->

<div class="skillbar clearfix " data-percent="25%">
	<div class="skillbar-title" style="background: #2980b9;"><span>CSS3</span></div>
	<div class="skillbar-bar" style="background: #3498db;"></div>
	<div class="skill-bar-percent">25%</div>
</div> <!-- End Skill Bar -->

<div class="skillbar clearfix " data-percent="50%">
	<div class="skillbar-title" style="background: #2c3e50;"><span>jQuery</span></div>
	<div class="skillbar-bar" style="background: #2c3e50;"></div>
	<div class="skill-bar-percent">50%</div>
</div> <!-- End Skill Bar -->

<div class="skillbar clearfix " data-percent="40%">
	<div class="skillbar-title" style="background: #46465e;"><span>PHP</span></div>
	<div class="skillbar-bar" style="background: #5a68a5;"></div>
	<div class="skill-bar-percent">40%</div>
</div> <!-- End Skill Bar -->

<div class="skillbar clearfix " data-percent="75%">
	<div class="skillbar-title" style="background: #333333;"><span>Wordpress</span></div>
	<div class="skillbar-bar" style="background: #525252;"></div>
	<div class="skill-bar-percent">75%</div>
</div> <!-- End Skill Bar -->

<div class="skillbar clearfix " data-percent="100%">
	<div class="skillbar-title" style="background: #27ae60;"><span>SEO</span></div>
	<div class="skillbar-bar" style="background: #2ecc71;"></div>
	<div class="skill-bar-percent">100%</div>
</div> <!-- End Skill Bar -->

<div class="skillbar clearfix " data-percent="70%">
	<div class="skillbar-title" style="background: #124e8c;"><span>Photoshop</span></div>
	<div class="skillbar-bar" style="background: #4288d0;"></div>
	<div class="skill-bar-percent">70%</div>
</div> <!-- End Skill Bar -->

<p><strong>SOURCE :</strong> http://w3lessons.info/2013/06/04/skill-bar-with-jquery-css3/</p>

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