网站页面加载动画代码

有时候网站服务器带宽不好或者用户网络不好，网站速度打开就会比较慢，那么用户等待就会比较无聊，下面准备了一个loading页面，可以在网站文件未完全加载完毕之前展示。

HTML部分，放在body标签下面（最好是最靠近body）

<div id="loader-wrapper">
    <div id="loader"></div>
    <div class="loader-section section-left"></div>
    <div class="loader-section section-right"></div>
    <div id="load_title">正在加载中，请稍后</div>
</div>

JS部分，放在body标签结束之前

<script>    
window.onload = function () {
        document.body.className += ' loaded';
    }
</script>

CSS部分，最好写入到一个单独的css文件，然后在网页的head内引入。

.chromeframe {
    margin: .2em 0;
    background: #ccc;
    color: #000;
    padding: .2em 0
}

#loader-wrapper {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 999999
}

#loader {
    display: block;
    position: relative;
    left: 50%;
    top: 50%;
    width: 150px;
    height: 150px;
    margin: -75px 0 0 -75px;
    border-radius: 50%;
    border: 3px solid transparent;
    border-top-color: #FFF;
    -webkit-animation: spin 2s linear infinite;
    -ms-animation: spin 2s linear infinite;
    -moz-animation: spin 2s linear infinite;
    -o-animation: spin 2s linear infinite;
    animation: spin 2s linear infinite;
    z-index: 1001
}

#loader:before {
    content: "";
    position: absolute;
    top: 5px;
    left: 5px;
    right: 5px;
    bottom: 5px;
    border-radius: 50%;
    border: 3px solid transparent;
    border-top-color: #FFF;
    -webkit-animation: spin 3s linear infinite;
    -moz-animation: spin 3s linear infinite;
    -o-animation: spin 3s linear infinite;
    -ms-animation: spin 3s linear infinite;
    animation: spin 3s linear infinite
}

#loader:after {
    content: "";
    position: absolute;
    top: 15px;
    left: 15px;
    right: 15px;
    bottom: 15px;
    border-radius: 50%;
    border: 3px solid transparent;
    border-top-color: #FFF;
    -moz-animation: spin 1.5s linear infinite;
    -o-animation: spin 1.5s linear infinite;
    -ms-animation: spin 1.5s linear infinite;
    -webkit-animation: spin 1.5s linear infinite;
    animation: spin 1.5s linear infinite
}

@-webkit-keyframes spin {
    0% {
        -webkit-transform: rotate(0deg);
        -ms-transform: rotate(0deg);
        transform: rotate(0deg)
    }

    100% {
        -webkit-transform: rotate(360deg);
        -ms-transform: rotate(360deg);
        transform: rotate(360deg)
    }
}

@keyframes spin {
    0% {
        -webkit-transform: rotate(0deg);
        -ms-transform: rotate(0deg);
        transform: rotate(0deg)
    }

    100% {
        -webkit-transform: rotate(360deg);
        -ms-transform: rotate(360deg);
        transform: rotate(360deg)
    }
}

#loader-wrapper .loader-section {
    position: fixed;
    top: 0;
    width: 51%;
    height: 100%;
    background: #1abc9c;/*背景色 原#1abc9c */
    z-index: 1000;
    -webkit-transform: translateX(0);
    -ms-transform: translateX(0);
    transform: translateX(0)
}

#loader-wrapper .loader-section.section-left {
    left: 0
}

#loader-wrapper .loader-section.section-right {
    right: 0
}

.loaded #loader-wrapper .loader-section.section-left {
    -webkit-transform: translateX(-100%);
    -ms-transform: translateX(-100%);
    transform: translateX(-100%);
    -webkit-transition: all .7s .3s cubic-bezier(0.645,0.045,0.355,1.000);
    transition: all .7s .3s cubic-bezier(0.645,0.045,0.355,1.000)
}

.loaded #loader-wrapper .loader-section.section-right {
    -webkit-transform: translateX(100%);
    -ms-transform: translateX(100%);
    transform: translateX(100%);
    -webkit-transition: all .7s .3s cubic-bezier(0.645,0.045,0.355,1.000);
    transition: all .7s .3s cubic-bezier(0.645,0.045,0.355,1.000)
}

.loaded #loader {
    opacity: 0;
    -webkit-transition: all .3s ease-out;
    transition: all .3s ease-out
}

/* 原版load_title是从上面飘出去，感觉太二了注销掉了，结束自动消失 */
.loaded #loader-wrapper {
    visibility: hidden;
    /*-webkit-transform: translateY(-100%);*/
    /*-ms-transform: translateY(-100%);*/
    /*transform: translateY(-100%);*/
    /*-webkit-transition: all .3s 1s ease-out;*/
    /*transition: all .3s 1s ease-out*/
}

.no-js #loader-wrapper {
    display: none
}

.no-js h1 {
    color: #222
}

#loader-wrapper #load_title {
    font-family: 'Open Sans';
    color: #FFF;
    font-size: 19px;
    width: 100%;
    text-align: center;
    z-index: 9999999999999;
    position: absolute;
    top: 60%;
    opacity: 1;
    line-height: 30px
}

#loader-wrapper #load_title span {
    font-weight: normal;
    font-style: italic;
    font-size: 13px;
    color: #FFF;
    opacity: .5
}

展示效果如下，中间是一个转圈圈的动画