javascript实现简单加载随机色方块

用碎片加载小方块实现简单的随机色块，直接上代码：
效果图：

具体代码：

css代码：

* {
 -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
   box-sizing: border-box;
}
html {
 font-size: 10px;
 -webkit-tap-highlight-color: transparent;
}
body {
 margin: 0;
 padding: 0;
 font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
 font-size: 14px;
 line-height: 1.42857143;
 color: #333;
 background-color: rgba(211,232,132,0.8);
}
.container {
 overflow: visible;
}
.main {
 position: relative;
 width: 90%;
 height:200px;
 margin:auto;
}
.colorful {
 overflow: visible;
 width: 100%;
 height: 100%;
}

.colorful > a {
 float: left;
 display: block;
 width: 50px;
 height: 50px;
 zoom:2;
}

.colorful > a:hover {
 -webkit-animation:infinite 2s ease-in-out start-roll;
 -moz-animation:infinite 2s ease-in-out start-roll;
   animation:infinite 2s ease-in-out start-roll;
}
@-webkit-keyframes start-roll{
 0% {
  -webkit-transform: rotate(0deg); 
  -moz-transform: rotate(0deg); 
  -ms-transform: rotate(0deg); 
  transform: rotate(0deg);
  -webkit-transition: opacity .3s linear;
  transition: opacity .3s linear;
  opacity: .5;
  filter: alpha(opacity=50);
  zoom:1;
 }
 50% {
  -webkit-transform: rotate(180deg); 
  -moz-transform: rotate(180deg); 
  -ms-transform: rotate(180deg); 
  transform: rotate(180deg);
  -webkit-transition: opacity 1s linear;
  transition: opacity 1s linear;
  opacity: 1;
  filter: alpha(opacity=100);
   zoom:2;
 }
 100% {
  -webkit-transform: rotate(360deg); 
  -moz-transform: rotate(360deg); 
  -ms-transform: rotate(360deg); 
  transform: rotate(360deg);
  -webkit-transition: opacity .3s linear;
  transition: opacity .3s linear;
  opacity: .5;
  filter: alpha(opacity=50);
  zoom:1;
 }
}
@-moz-keyframes start-roll{
 0% {
  -webkit-transform: rotate(0deg); 
  -moz-transform: rotate(0deg); 
  -ms-transform: rotate(0deg); 
  transform: rotate(0deg);
  -webkit-transition: opacity .3s linear;
  transition: opacity .3s linear;
  opacity: .5;
  filter: alpha(opacity=50);
 }
 50% {
  -webkit-transform: rotate(180deg); 
  -moz-transform: rotate(180deg); 
  -ms-transform: rotate(180deg); 
  transform: rotate(180deg);
  -webkit-transition: opacity 1s linear;
  transition: opacity 1s linear;
  opacity: .5;
  filter: alpha(opacity=50);
 }
 100% {
  -webkit-transform: rotate(360deg); 
  -moz-transform: rotate(360deg); 
  -ms-transform: rotate(360deg); 
  transform: rotate(360deg);
  -webkit-transition: opacity .3s linear;
  transition: opacity .3s linear;
  opacity: .5;
  filter: alpha(opacity=50);
 }
}
@keyframes start-roll{
 0% {
  -webkit-transform: rotate(0deg); 
  -moz-transform: rotate(0deg); 
  -ms-transform: rotate(0deg); 
  transform: rotate(0deg);
  -webkit-transition: opacity .3s linear;
  transition: opacity .3s linear;
  opacity: .5;
  filter: alpha(opacity=50);
 }
 50% {
  -webkit-transform: rotate(180deg); 
  -moz-transform: rotate(180deg); 
  -ms-transform: rotate(180deg); 
  transform: rotate(180deg);
  -webkit-transition: opacity 1s linear;
  transition: opacity 1s linear;
  opacity: .5;
  filter: alpha(opacity=50);
 }
 100% {
  -webkit-transform: rotate(360deg); 
  -moz-transform: rotate(360deg); 
  -ms-transform: rotate(360deg); 
  transform: rotate(360deg);
  -webkit-transition: opacity .3s linear;
  transition: opacity .3s linear;
  opacity: .5;
  filter: alpha(opacity=50);
 }
}

js代码：

(function (window) {
 var document = window.document;
 function on(elem, evtnm, eventhd) {
  var onevtnm = 'on' + evtnm;
  elem[onevtnm] = eventhd;
 }
 function grc() {
  var val = [], i = 0;
  while (++i <= 3) {
   val.push(Math.floor(Math.random() * 255));
  }
  return 'rgb(' + val.join() + ')';
 }
 function fbc() {
  var el = document.querySelectorAll('.colorful')[0],
   total = Math.floor(el.offsetWidth / 50) * Math.floor(el.offsetHeight / 50),
   df = document.createdocumentFragment(),
   a;
  while (total-- > 0) {
   a = document.createElement('a');
   a.style.backgroundColor = grc();
   df.appendChild(a);
  }
  el.appendChild(df);
 }
 on(window, 'load', function () {
  fbc();
 });
})(window)

希望本文所述对大家学习javascript程序设计有所帮助。