jQuery-如何仅在查看时加载计数器? [英] jQuery - How do I get my counter to load only when in view?

问题描述

我对修补jQuery非常陌生.我找到了一种针对计数器的解决方案，该计数器用于显示节省的百分比.

I am super new to tinkering around with jQuery. I found a solution for a counter that counts up that serves the purpose for showing savings in %.

我遇到的问题是，它会在页面加载后立即运行，并且该元素在屏幕下方更远一点，并且它失去了效果，因为当访问者看到该站点时，计数器已经达到了数字.

The problem that I have with it, is that it runs as soon as the page loads, and the element is a bit further down the screen, and it looses the effect because by the time a visitor sees the site, the counter has already reached the number.

我需要等待加载，直到它在浏览器中出现.感谢您的帮助.谢谢.

I need to wait to load until it comes into view within the browser. I appreciate any help. Thank you.

(function ($) {
	$.fn.countTo = function (options) {
		options = options || {};

		return $(this).each(function () {
			// set options for current element
			var settings = $.extend({}, $.fn.countTo.defaults, {
				from:            $(this).data('from'),
				to:              $(this).data('to'),
				speed:           $(this).data('speed'),
				refreshInterval: $(this).data('refresh-interval'),
				decimals:        $(this).data('decimals')
			}, options);

			// how many times to update the value, and how much to increment the value on each update
			var loops = Math.ceil(settings.speed / settings.refreshInterval),
				increment = (settings.to - settings.from) / loops;

			// references & variables that will change with each update
			var self = this,
				$self = $(this),
				loopCount = 0,
				value = settings.from,
				data = $self.data('countTo') || {};

			$self.data('countTo', data);

			// if an existing interval can be found, clear it first
			if (data.interval) {
				clearInterval(data.interval);
			}
			data.interval = setInterval(updateTimer, settings.refreshInterval);

			// initialize the element with the starting value
			render(value);

			function updateTimer() {
				value += increment;
				loopCount++;

				render(value);

				if (typeof(settings.onUpdate) == 'function') {
					settings.onUpdate.call(self, value);
				}

				if (loopCount >= loops) {
					// remove the interval
					$self.removeData('countTo');
					clearInterval(data.interval);
					value = settings.to;

					if (typeof(settings.onComplete) == 'function') {
						settings.onComplete.call(self, value);
					}
				}
			}

			function render(value) {
				var formattedValue = settings.formatter.call(self, value, settings);
				$self.text(formattedValue);
			}
		});
	};

	$.fn.countTo.defaults = {
		from: 0,               // the number the element should start at
		to: 0,                 // the number the element should end at
		speed: 5000,           // how long it should take to count between the target numbers
		refreshInterval: 1000,  // how often the element should be updated
		decimals: 0,           // the number of decimal places to show
		formatter: formatter,  // handler for formatting the value before rendering
		onUpdate: null,        // callback method for every time the element is updated
		onComplete: null       // callback method for when the element finishes updating
	};

	function formatter(value, settings) {
		return value.toFixed(settings.decimals);
	}
}(jQuery));

<div class="ui-129 text-center">
  <div id="counter" class="counter-item">
    <!-- Icon -->
    <i class="fa fa-usd green">                                              
      <!-- Number -->
    <span class="number-count" data-from="0" data-to="28" data-speed="5000" data-refresh-interval="10"></span>%
    </i>
    <!-- Border -->
    <hr class="br-green" />
    <!-- Heading -->
    <h5>less than the "other guys"</h5>
  </div>
</div>
<!-- End CountUP -->

<script> <!-- I have this script in my custom.js folder, not in the html -->
    $(document).ready(function(){
        $('.number-count').countTo();
			
    });		
</script>

所有CSS都可以渲染并正常运行..如果我需要在此处添加它，请告诉我，我很乐意这样做.

All of the CSS renders and runs properly .. if I need to add it here, please let me know, I'll be happy to do so.

推荐答案

您可以使用scroll事件来操纵脚本.

You can manipulate your script using scroll event.

function isScrolledIntoView(elem) {
  var $elem = $(elem);
  var $window = $(window);

  var docViewTop = $window.scrollTop();
  var docViewBottom = docViewTop + $window.height();

  var elemTop = $elem.offset().top;
  var elemBottom = elemTop + $elem.height();

  return ((elemBottom <= docViewBottom) && (elemTop >= docViewTop));
}
var message = $('#message');
$(window).scroll(function() {
  if (isScrolledIntoView('#hiddenElem')) {
    message.text("Visible");
  } else {
    message.text("Invisible");
  }
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<h3 style="position:fixed;top: 0;left: 0;background: white" id="message"></h3>
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<br>Hello..
<div id="hiddenElem">HiddenElem</div>

根据您的情况，请尝试以下操作:

In your case, try this:

$(window).on('scroll', function () {
    if (isScrolledIntoView('#hiddenElem')) {
        $('.number-count').countTo();
        $(window).off('scroll');
    }
});

这篇关于jQuery-如何仅在查看时加载计数器?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！