Javascript图像加载器 [英] Javascript image loader

问题描述

我有这个脚本，可以在索引页面上预加载一堆图像，以便当人们进入我的产品页面时，图像已经在其缓存中.问题是，当我删除代码中的两个警报以使其不通知用户时，脚本将无法工作.

我在做什么错了?

 < script type ="text/javascript">var imageFiles = new Array<?= $ output?>var imagesLoaded = new Number(0);document.addEventListener("DOMContentLoaded"，init，false);函数init(){var images = new Array();alert("lkasd oe kdfl ke k");for(i = 0; i< imageFiles.length; i ++)images [i] = loadImage(imageFiles [i]);}函数loadImage(url){var image = new Image();image.addEventListener("load"，imageLoaded，false);image.src =网址;返回图像；}函数imageLoaded(){imagesLoaded ++;如果(imagesLoaded == imageFiles.length)alert("Billederne er blevet preloadet og ligger i cachen".)；}</script> 

解决方案

我想您没有注释掉 if 和 alert .>

出于这个原因，我们在进行{}放弃工作时曾遇到过激烈的战争.= D

 < script type ="text/javascript">var imageFiles = new Array<?= $ output?>var imagesLoaded = new Number(0);document.addEventListener("DOMContentLoaded"，init，false);函数init(){var images = new Array();//alert("lkasd oe kdfl ke k");for(i = 0; i< imageFiles.length; i ++)images [i] = loadImage(imageFiles [i]);}函数loadImage(url){var image = new Image();image.addEventListener("load"，imageLoaded，false);image.src =网址;返回图像；}函数imageLoaded(){imagesLoaded ++;//如果(imagesLoaded == imageFiles.length)//alert("Billederne er blevet preloadet og ligger i cachen.");}</script> 

I have this script that preloads a stack of images on my index page so that when people move on to my product page, the images are already in their cache. The problem is, when I remove the two alerts in the code so that it does not notify the user, the script won't work.

What am I doing wrong?

<script type="text/javascript">
  var imageFiles = new Array<?=$output?>
  var imagesLoaded = new Number(0);
  document.addEventListener("DOMContentLoaded", init, false);
  function init()
  {
    var images = new Array();

    alert("lkasd oe kdfl ke k");

    for(i=0; i<imageFiles.length; i++)
    images[i] = loadImage(imageFiles[i]);
  }
  function loadImage(url)
  {
    var image = new Image();
    image.addEventListener("load", imageLoaded, false);
    image.src = url;
    return image;
  }
  function imageLoaded()
  {
    imagesLoaded++;

    if (imagesLoaded == imageFiles.length)
      alert("Billederne er blevet preloadet og ligger i cachen.");
  }

</script>

解决方案

I am guessing you didn't comment out your if as well as the alert.

We've had holy wars at my work about leaving off the { } for this very reason. =D

<script type="text/javascript">
  var imageFiles = new Array<?=$output?>
  var imagesLoaded = new Number(0);
  document.addEventListener("DOMContentLoaded", init, false);
  function init()
  {
    var images = new Array();

    //alert("lkasd oe kdfl ke k");

    for(i=0; i<imageFiles.length; i++)
    images[i] = loadImage(imageFiles[i]);
  }
  function loadImage(url)
  {
    var image = new Image();
    image.addEventListener("load", imageLoaded, false);
    image.src = url;
    return image;
  }
  function imageLoaded()
  {
    imagesLoaded++;

    //if (imagesLoaded == imageFiles.length)
    //  alert("Billederne er blevet preloadet og ligger i cachen.");
  }

</script>

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