預設情況下如果網站請求速度慢，所以會有一段時間的空白頁面等等，使用者體驗效果不好，見到很多的頁面都有預載入的效果，載入之前先載入一個動畫，後臺程序繼續載入頁面內容，當頁面內容載入完之後再退出動畫顯示內容，這樣的使用者體驗更好。

這篇文章是從上面連結的內容上拔下來的，操作流程很簡單，只有兩部如下

首先定義一個loader.css檔案，如下內容

.chromeframe {
    margin: 0.2em 0;
    background: #ccc;
    color: #000;
    padding: 0.2em 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;
    /* COLOR 1 */
 

    border-top-color: #FFF;
    -webkit-animation: spin 2s linear infinite; /* Chrome, Opera 15+, Safari 5+ */
    -ms-animation: spin 2s linear infinite; /* Chrome, Opera 15+, Safari 5+ */
    -moz-animation: spin 2s linear infinite; /* Chrome, Opera 15+, Safari 5+ */ 
    -o-animation: spin 2s linear infinite
 
; /* Chrome, Opera 15+, Safari 5+ */   
        animation: spin 2s linear infinite; /* Chrome, Firefox 16+, IE 10+, Opera */
    z-index:1001;}
#loader:before {
        content: "";
        position: absolute;
        top: 5px;
        left: 5px;
        right: 5px;
        bottom: 5px;
        border-radius: 50%;
        border: 3px solid transparent;
        /* COLOR 2 */       
        border-top-color: #FFF;
        -webkit-animation: spin 3s linear infinite; /* Chrome, Opera 15+, Safari 5+ */
        -moz-animation: spin 3s linear infinite; /* Chrome, Opera 15+, Safari 5+ */
        -o-animation: spin 3s linear infinite; /* Chrome, Opera 15+, Safari 5+ */
        -ms-animation: spin 3s linear infinite; /* Chrome, Opera 15+, Safari 5+ */              
        animation: spin 3s linear infinite; /* Chrome, Firefox 16+, IE 10+, Opera */}
#loader:after {
        content: "";
        position: absolute;
        top: 15px;
        left: 15px;
        right: 15px;
        bottom: 15px;
        border-radius: 50%;
        border: 3px solid transparent;
        border-top-color: #FFF;
        /* COLOR 3 */       
        -moz-animation: spin 1.5s linear infinite; /* Chrome, Opera 15+, Safari 5+ */
        -o-animation: spin 1.5s linear infinite; /* Chrome, Opera 15+, Safari 5+ */
        -ms-animation: spin 1.5s linear infinite; /* Chrome, Opera 15+, Safari 5+ */        
        -webkit-animation: spin 1.5s linear infinite; /* Chrome, Opera 15+, Safari 5+ */
          animation: spin 1.5s linear infinite; /* Chrome, Firefox 16+, IE 10+, Opera */}


@-webkit-keyframes spin {
        0%{ 
            -webkit-transform: rotate(0deg);  /* Chrome, Opera 15+, Safari 3.1+ */
            -ms-transform: rotate(0deg);  /* IE 9 */
            transform: rotate(0deg);  /* Firefox 16+, IE 10+, Opera */
        }100%{
            -webkit-transform: rotate(360deg);  /* Chrome, Opera 15+, Safari 3.1+ */
            -ms-transform: rotate(360deg);  /* IE 9 */
            transform: rotate(360deg);  /* Firefox 16+, IE 10+, Opera */}
}

@keyframes spin {
        0%{ 
            -webkit-transform: rotate(0deg);  /* Chrome, Opera 15+, Safari 3.1+ */
            -ms-transform: rotate(0deg);  /* IE 9 */
            transform: rotate(0deg);  /* Firefox 16+, IE 10+, Opera */
        }100%{
            -webkit-transform: rotate(360deg);  /* Chrome, Opera 15+, Safari 3.1+ */
            -ms-transform: rotate(360deg);  /* IE 9 */
            transform: rotate(360deg);  /* Firefox 16+, IE 10+, Opera */}
}


#loader-wrapper .loader-section {
        position: fixed;
        top: 0;
        width: 51%;
        height: 100%;
        background: #1abc9c; /* Old browsers */
        z-index: 1000;
        -webkit-transform: translateX(0);  /* Chrome, Opera 15+, Safari 3.1+ */
        -ms-transform: translateX(0);  /* IE 9 */
        transform: translateX(0);  /* Firefox 16+, IE 10+, Opera */}
#loader-wrapper .loader-section.section-left {left: 0;}
#loader-wrapper .loader-section.section-right {right: 0;}

/* Loaded */
.loaded #loader-wrapper .loader-section.section-left {
        -webkit-transform: translateX(-100%);  /* Chrome, Opera 15+, Safari 3.1+ */
            -ms-transform: translateX(-100%);  /* IE 9 */
                transform: translateX(-100%);  /* Firefox 16+, IE 10+, Opera */
        -webkit-transition: all 0.7s 0.3s cubic-bezier(0.645, 0.045, 0.355, 1.000);  
                transition: all 0.7s 0.3s cubic-bezier(0.645, 0.045, 0.355, 1.000);}
.loaded #loader-wrapper .loader-section.section-right {
        -webkit-transform: translateX(100%);  /* Chrome, Opera 15+, Safari 3.1+ */
            -ms-transform: translateX(100%);  /* IE 9 */
                transform: translateX(100%);  /* Firefox 16+, IE 10+, Opera */
        -webkit-transition: all 0.7s 0.3s cubic-bezier(0.645, 0.045, 0.355, 1.000);  
        transition: all 0.7s 0.3s cubic-bezier(0.645, 0.045, 0.355, 1.000);}
.loaded #loader {
        opacity: 0;
        -webkit-transition: all 0.3s ease-out;  
                transition: all 0.3s ease-out;}
.loaded #loader-wrapper {
        visibility: hidden;
        -webkit-transform: translateY(-100%);  /* Chrome, Opera 15+, Safari 3.1+ */
            -ms-transform: translateY(-100%);  /* IE 9 */
                transform: translateY(-100%);  /* Firefox 16+, IE 10+, Opera */
        -webkit-transition: all 0.3s 1s ease-out;  
                transition: all 0.3s 1s ease-out;}
/* JavaScript Turned Off */
.no-js #loader-wrapper {display: none;}
.no-js h1 {color: #222222;}
#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:0.5;}

第二步：在網站頁面header標籤和body標籤加入以下程式碼

// 引入jquery 

<!--頁面載入start-->
<link rel="stylesheet" type="text/css" href="css/loader.min.css">

<script type="text/javascript">         
    // 等待所有載入
    $(window).load(function(){
        $('body').addClass('loaded');
        $('#loader-wrapper .load_title').remove();
    }); 
</script>    

<div id="loader-wrapper">
    <div id="loader"></div>
    <div class="loader-section section-left"></div>
    <div class="loader-section section-right"></div>
    <div class="load_title">正在載入LoveFeel站點<br><span>V1.0</span></div>
</div>
<!--頁面載入end-->

HoverAlls頁面原始碼如下操作，他先是載入一段json封裝之後再顯示內容的，我上面的程式碼省去了json的操作。

$(window).load(function(){
    $('body').addClass('loaded').Chameleon({
        'current_item':'hoveralls',
        'json_url':'../Envato/items.json'
    });
    $('#loader-wrapper .load_title').remove();
}); 

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