jquery中的CSS动画属性

Question

So I want to generate a random number in JS to concatenate inside the css animation property, so that it has a random time property.

As you can imagine, from my code snippet, this is a preloader. I want it to have a random time (from 2 to 8 seconds long)

$(window).load(function() {

  var rnd = Math.random() * (8000 - 2000) + 2000;

  $('.progress').css(function() {
    "animation": "load" + rnd + "linear"
  });

  setTimeout(function() {

    $('#page').addClass('loaded');
    $('#page').removeClass('unloaded');
    $('#loader').hide();

  }, val);

});

Answer 1

You're not appending a time unit on your animation duration. You could either assign ms using "animation": "load " + rnd + "ms linear" (see how I'm leaving spaces in between the variable) or you could divide your rnd variable as it's outputting values in thousands and use s through "animation": "load " + rnd/1000 + "s linear" .

If this doesn't work, please provide a MCV example and we will help you further.

EDIT: Check this, I've updated your code snippet. The problem was that .css( property, value) and not a function as you sent.

 $(window).load(function() { var rnd = Math.random() * (8000 - 2000) + 2000; $('.progress').css("animation", "load " + rnd + "ms linear"); setTimeout(function() { $('#page').addClass('loaded'); $('#page').removeClass('unloaded'); $('#loader').hide(); }, rnd); }); 

 #page { position: absolute; background: rgb(240, 240, 240); height: 100%; width: 100%; } #loader { position: absolute; top: calc(50% - 10px); left: calc(25%); width: 50%; } .progress { width: 100%; height: 20px; background: #3498db; border-top-left-radius: 5px; border-top-right-radius: 5px; border-bottom-left-radius: 5px; border-bottom-right-radius: 5px; } .loaded { opacity: 1; } .unloaded { opacity: 0; } @keyframes load { 0% { width: 0%; } 25% { width: 50%; } 50% { width: 60%; } 90% { width: 95%; } 100% { width: 100%; } } 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <div id="loader"> <div class="progress"></div> </div> <div id="page" class="unloaded"> Loaded result </div>