CSS3扁平化风格APP图标动画

之前分享过一篇非常精致的时钟效果：《纯CSS3打造精致时钟（不含任何图片和js）》非常受大家喜欢。今天给大家带来了另外一种扁平化风格APP时钟动态图标。其外观（表盘、刻度、指针）都使用css来绘制，然后再通过javascript来获取当前时间并且让时钟动起来。有了这个优美的动态时钟，我再也不要看手表了，哈哈。

惯例先提供demo效果以及附件下载：

查看预览下载附件

下面我们一起来看看具体的实现方式。

一、HTML结构代码

结构比较简单：表盘（icon-clock）、内圆（clock）、刻度（ol）以及时针（hour）、分针（min）、秒针（sec）。具体如下：

<div class="icon-large icon-clock">
  <div class="clock">
    <ol>
      <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
        <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
    </ol>
    <div id="hour"></div>
    <div id="min"></div>
    <div id="sec"></div>
  </div>
</div>

二、CSS绘制时钟样式

通过css3的变换以及旋转等属性来绘制出漂亮的扁平化时钟。

html, body {
  height: 100%;
  background: #ffd740;
  position: relative;
}
.icon-large {
  width: 220px;
  height: 220px;
  border-radius: 38px;
  margin:auto auto 60px auto;
  position: relative;
}
.icon-clock {
  overflow: hidden;
  background: #000;
}
.clock {
  width: 192px;
  height: 192px;
  border-radius: 50%;
  background: #f1f1f1;
  position: absolute;
  top: 50%;
  left: 50%;
  -webkit-transform: translate(-50%, -50%);
      -ms-transform: translate(-50%, -50%);
          transform: translate(-50%, -50%);
}
.clock ol {
  list-style-type: none;
  width: 100%;
  height: 100%;
  position: relative;
  margin: 0;
  padding: 0;
}
.clock ol li {
  counter-increment: labelCounter;
  position: absolute;
  font-size: 1.25em;
}
.clock ol li:before {
  font-family: 'Helvetica';
  content: counter(labelCounter) "";
}
.clock ol li:nth-child(1) {
  right: 55px;
  top: 20px;
}
.clock ol li:nth-child(2) {
  right: 25px;
  top: 50px;
}
.clock ol li:nth-child(3) {
  right: 12px;
  top: 85px;
}
.clock ol li:nth-child(4) {
  right: 25px;
  top: 125px;
}
.clock ol li:nth-child(5) {
  right: 55px;
  top: 150px;
}
.clock ol li:nth-child(6) {
  right: 90px;
  top: 160px;
}
.clock ol li:nth-child(7) {
  right: 125px;
  top: 150px;
}
.clock ol li:nth-child(8) {
  right: 155px;
  top: 125px;
}
.clock ol li:nth-child(9) {
  right: 165px;
  top: 85px;
}
.clock ol li:nth-child(10) {
  right: 150px;
  top: 50px;
}
.clock ol li:nth-child(11) {
  right: 120px;
  top: 20px;
}
.clock ol li:nth-child(12) {
  right: 85px;
  top: 10px;
}
@-webkit-keyframes spin {
  100% {
    -webkit-transform: rotate(360deg);
            transform: rotate(360deg);
  }
}
@keyframes spin {
  100% {
    -webkit-transform: rotate(360deg);
            transform: rotate(360deg);
  }
}
#hour {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: #303030;
  position: absolute;
  top: 50%;
  left: 50%;
  margin-top: -7px;
  margin-left: -7px;
}
#hour:before, #hour:after {
  content: "";
  display: block;
  position: absolute;
}
#hour:before {
  width: 8px;
  height: 65px;
  border-radius: 4px;
  background: #303030;
  position: absolute;
  bottom: 2px;
  left: 50%;
  -webkit-transform: translate(-50%, 0);
      -ms-transform: translate(-50%, 0);
          transform: translate(-50%, 0);
}
#min {
  width: 0;
  height: 0;
  border-radius: 50%;
  background: #303030;
  position: absolute;
  top: 50%;
  left: 50%;
}
#min:before, #min:after {
  content: "";
  display: block;
  position: absolute;
}
#min:before {
  width: 6px;
  height: 90px;
  border-radius: 4px;
  background: #303030;
  position: absolute;
  bottom: 2px;
  left: 50%;
  -webkit-transform: translate(-50%, 0);
      -ms-transform: translate(-50%, 0);
          transform: translate(-50%, 0);
}
#sec {
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: #dd3e1c;
  border: 2px solid #e13e1b;
  position: absolute;
  top: 50%;
  left: 50%;
  margin-top: -4px;
  margin-left: -4px;
}
#sec:before, #sec:after {
  content: "";
  display: block;
  position: absolute;
}
#sec:before {
  width: 2px;
  height: 105px;
  border-radius: 4px;
  background: #e13e1b;
  position: absolute;
  bottom: -12px;
  left: 50%;
  -webkit-transform: translate(-50%, 0);
      -ms-transform: translate(-50%, 0);
          transform: translate(-50%, 0);
}

三、JavaScript让时钟动起来

到这里基本完成了时钟效果，最后我们通过javascript来获取当前时间，然后让时钟动起来。参考代码如下：

//use requestAnimationFrame for smoothness (shimmed with setTimeout fallback)
window.requestAnimFrame = (function(){
  return  window.requestAnimationFrame       ||
          window.webkitRequestAnimationFrame ||
          window.mozRequestAnimationFrame    ||
          function( callback ){
              window.setTimeout(callback, 1000 / 60);
          };
})();

//initialize the clock in a self-invoking function
(function clock(){ 
    var hour = document.getElementById("hour"),
        min = document.getElementById("min"),
        sec = document.getElementById("sec");
    //set up a loop
    (function loop(){
        requestAnimFrame(loop);
        draw();
    })();
    //position the hands
    function draw(){
        var now = new Date(),//now
            then = new Date(now.getFullYear(),now.getMonth(),now.getDate(),0,0,0),//midnight
            diffInMil = (now.getTime() - then.getTime()),// difference in milliseconds
            h = (diffInMil/(1000*60*60)),//hours
            m = (h*60),//minutes
            s = (m*60);//seconds
        //rotate the hands accordingly
        sec.style.webkitTransform = "rotate(" + (s * 6) + "deg)";
        hour.style.webkitTransform = "rotate(" + (h * 30 + (h / 2)) + "deg)";
        min.style.webkitTransform = "rotate(" + (m * 6) + "deg)";
    } 
})();

查看预览下载附件

好了，今天的分享就到这里，如果你们也有不错的、好玩的东西也可以跟觉唯一起分享哦。顺便推广下觉唯的用户中心，各位可以前往用户中心去发布文章作品。期待你的精彩。