如何通过jQuery ImagesLoaded加载大量图像

时间:2015-01-31 06:07:34

标签: jquery image loading preload imagesloaded

我有一个页面可以将大约150多张图像加载到页面中。图像的结构是这样的:

HTML CODE

<table class="form-table">
  <input type="hidden" name="bgtype" id="bgtype" value="pattern"/>
  <tr class="wpbp-field-patternbg">
    <th style="width:20%"><label for="patternbg">Pattern</label></th>
    <td><div id="wpbp-pattern-select">
        <div class="description">Select a pattern you would like to be applied as the background. Click on a pattern to select it.<br>
        </div>
        <input class="radio" type="radio" name="patternbg" id="patternbg2" value="45degreee_fabric.png"  checked='checked'>
        <label for="patternbg2" class="is-loading"><a class="pattern_preview" data-img="45degreee_fabric.png" data-content="45degreee fabric"><img src="45degreee_fabric.png" alt="" class="wpbp-pattern-img "/></a></label>
        <input class="radio" type="radio" name="patternbg" id="patternbg3" value="patterns/60degree_gray.png" >
        <label for="patternbg3" class="is-loading"><a class="pattern_preview" data-img="60degree_gray.png" data-content="60degree gray"><img src="60degree_gray.png" alt="" class="wpbp-pattern-img "/></a></label>
        <input class="radio" type="radio" name="patternbg" id="patternbg4" value="always_grey.png" >
        <label for="patternbg4" class="is-loading"><a class="pattern_preview" data-img="always_grey.png" data-content="always grey"><img src="always_grey.png" alt="" class="wpbp-pattern-img "/></a></label>
        </div></td>
  </tr>
</table>

(我删除了图像的完整路径以使上面的代码最少)

CSS代码

#wpbp-pattern-select.is-loading {
  background-image: url('../images/loading.gif');

}
#wpbp-pattern-select .is-loading img {
  opacity: 0;
}

JQUERY

var $container = $('#wpbp-pattern-select');
$imgs = $container.find('img'),

// use ImagesLoaded
$container.imagesLoaded()
  .progress( onProgress )
// reset progress counter
imageCount = $container.find('img').length;
console.log( imageCount + ' properly loaded images' );

// triggered after each item is loaded
function onProgress( imgLoad, image ) {
  var $item = $container.find('img');
  $item.removeClass('is-loading');
}

我想要实现的是在每个单独的图像上显示预加载微调器(.is-loaded),直到加载了某个图像。完成加载后,微调器将删除显示原始图像。

我尝试过使用jQuery imagesLoaded库来实现这一点,但我无法正确使用它。可以这样做吗?

非常感谢任何帮助,谢谢

1 个答案:

答案 0 :(得分:3)

好的,首先在你的CSS中定义#wpbp-pattern-select .is-loading img,但在你的JS中,你试图从图像本身中删除该类:

function onProgress( imgLoad, image ) {
  var $item = $container.find('img');
  $item.removeClass('is-loading');
}

这是设计的吗?但是,请尝试以下js:

$(document).ready(function(){
  var $container = $('#wpbp-pattern-select');
    $imgs = $container.find('img');

  // all images are hidden by css

  $imgs.each(function() {
    var el = $(this),
        checkforloaded = setInterval(function() {
          var image = el.get(0);
          if (image.complete || image.readyState == 'complete' || image.readyState == 4) {
            clearInterval(checkforloaded);
            el.removeClass('is-loading'); // or: el.closest('label').removeClass('is-loading');
          }
        }, 20);
  });
});

我只是不确定这将如何与许多图像一起执行,但