仿Battle.net超酷loading进度条特效

这是一款仿照Battle.net网站的超酷loading进度条特效。该进度条特效在进度变化的时候会有光波冲击效果，并且进度条的颜色会随进度而相应的变化，以及有详细的当前进度的文本标签。

制作方法

HTML结构

该loading进度条特效的HTML结构使用一个<div>作为包裹容器，里面使用<b>元素作为进度条的进度，进度条上的文本是最内层的<span>元素。

<div class="progress">
  <b class="progress__bar">
    <span class="progress__text">
      Progress: <em>0%</em>
    </span>
  </b>
</div>          
              

CSS样式

首先为进度条的包裹元素设置一些基本样式：

.progress {
  font-size: 1.2em;
  height: 20px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: 2px;
  border: 1px solid rgba(255, 255, 255, 0.2);
}        
              

进度条的简单使用了透明度，宽度，背景色，边框色和阴影变化的过渡动画效果。并使用了pulse的CSS3 animation动画，这个动画修改background-position属性，使进度条中的光波不断的往前运动。

.progress__bar {
  color: white;
  font-size: 12px;
  font-weight: normal;
  text-shadow: 0 1px 1px rgba(0, 0, 0, 0.6);
  line-height: 19px;
  display: block;
  position: relative;
  top: -1px;
  left: -1px;
  width: 0%;
  height: 100%;
  opacity: 0;
  border: 1px solid;
  border-radius: 2px 0 0 2px;
  background-size: 100px 30px, 130px 30px, 130px 30px;
  background-position: -20% center, right center, left center;
  background-repeat: no-repeat, no-repeat, no-repeat;
  -webkit-transition: opacity 0.2s ease, width 0.8s ease-out, 
                      background-color 1s ease, border-color 0.3s ease, 
                      box-shadow 1s ease;
          transition: opacity 0.2s ease, width 0.8s ease-out, 
                      background-color 1s ease, border-color 0.3s ease, 
                      box-shadow 1s ease;
  -webkit-animation: pulse 2s ease-out infinite;
          animation: pulse 2s ease-out infinite;
  background-color: rgba(201, 4, 20, 0.95);
  background-image: -webkit-linear-gradient(0deg, rgba(226, 4, 22, 0) 10%, rgba(250, 6, 26, 0.8) 30%, #fb1f31 70%, rgba(250, 6, 26, 0.8) 80%, rgba(226, 4, 22, 0) 90%), -webkit-linear-gradient(left, rgba(251, 31, 49, 0) 0%, #fb1f31 100%), -webkit-linear-gradient(right, rgba(251, 31, 49, 0) 0%, #fb1f31 100%);
  background-image: linear-gradient(90deg, rgba(226, 4, 22, 0) 10%, rgba(250, 6, 26, 0.8) 30%, #fb1f31 70%, rgba(250, 6, 26, 0.8) 80%, rgba(226, 4, 22, 0) 90%), linear-gradient(to right, rgba(251, 31, 49, 0) 0%, #fb1f31 100%), linear-gradient(to left, rgba(251, 31, 49, 0) 0%, #fb1f31 100%);
  border-color: #fb3848;
  box-shadow: 0 0 0.6em #fa061a inset, 0 0 0.4em #e20416 inset, 0 0 0.5em rgba(201, 4, 20, 0.5), 0 0 0.1em rgba(254, 206, 210, 0.5);
}                
              

样式中还为各种不同颜色的进度条设置了样式。

.progress__bar--orange {
  background-color: rgba(201, 47, 0, 0.95);
  background-image: -webkit-linear-gradient(0deg, rgba(227, 53, 0, 0) 10%, rgba(252, 59, 0, 0.8) 30%, #ff4d17 70%, rgba(252, 59, 0, 0.8) 80%, rgba(227, 53, 0, 0) 90%), -webkit-linear-gradient(left, rgba(255, 77, 23, 0) 0%, #ff4d17 100%), -webkit-linear-gradient(right, rgba(255, 77, 23, 0) 0%, #ff4d17 100%);
  background-image: linear-gradient(90deg, rgba(227, 53, 0, 0) 10%, rgba(252, 59, 0, 0.8) 30%, #ff4d17 70%, rgba(252, 59, 0, 0.8) 80%, rgba(227, 53, 0, 0) 90%), linear-gradient(to right, rgba(255, 77, 23, 0) 0%, #ff4d17 100%), linear-gradient(to left, rgba(255, 77, 23, 0) 0%, #ff4d17 100%);
  border-color: #ff6030;
  box-shadow: 0 0 0.6em #fc3b00 inset, 0 0 0.4em #e33500 inset, 0 0 0.5em rgba(201, 47, 0, 0.5), 0 0 0.1em rgba(255, 214, 201, 0.5);
}
...                
              

JAVASCRIPT

该进度条特效使用jQuery来获取当前进度的百分比值，并根据这个百分比值来修改进度条的颜色。最后他在文档中绑定了一个click事件，用于在点击文档任意位置时重置进度条。

var $progress = $('.progress'), $bar = $('.progress__bar'), 
    $text = $('.progress__text'), percent = 0, update, resetColors, 
    speed = 200, orange = 30, yellow = 55, green = 85, timer;
resetColors = function () {
    $bar.removeClass('progress__bar--green').removeClass('progress__bar--yellow')
        .removeClass('progress__bar--orange').removeClass('progress__bar--blue');
    $progress.removeClass('progress--complete');
};
update = function () {
    timer = setTimeout(function () {
        percent += Math.random() * 1.8;
        percent = parseFloat(percent.toFixed(1));
        $text.find('em').text(percent + '%');
        if (percent >= 100) {
            percent = 100;
            $progress.addClass('progress--complete');
            $bar.addClass('progress__bar--blue');
            $text.find('em').text('Complete');
        } else {
            if (percent >= green) {
                $bar.addClass('progress__bar--green');
            } else if (percent >= yellow) {
                $bar.addClass('progress__bar--yellow');
            } else if (percent >= orange) {
                $bar.addClass('progress__bar--orange');
            }
            speed = Math.floor(Math.random() * 900);
            update();
        }
        $bar.css({ width: percent + '%' });
    }, speed);
};
setTimeout(function () {
    $progress.addClass('progress--active');
    update();
}, 1000);
$(document).on('click', function (e) {
    percent = 0;
    clearTimeout(timer);
    resetColors();
    update();
});