jQuery實現線上文件

weixin_34391854發表於2013-11-29

原文網址 : https://blog.csdn.net/weixin_34391854/article/details/85594772

jQuery

1.1.1 摘要

現在，許多網站都提供線上圖片和圖書閱讀的功能，這種方式比下載後閱讀來的直觀和人性化，要實現該功能涉及到點選處理和圖片動態載入。

在接下來的博文中，我們將通過Javascript方式實現線上閱讀這一功能。

1.1.2 正文

Index頁面

首先，我們建立index.html頁面，它包含三個div元素分別是content、controls和doccontainer，其中controls用來顯示翻頁控制元件（前/後翻），而doccontainer用於顯示圖片，具體定義如下：

<!doctype html>
<html lang="en-US">
<head>
    <meta http-equiv="Content-Type" content="text/html;charset=utf-8">
    <title>Online Document Viewer Demo</title>
    <meta name="author" content="JK_Rush">
    <link rel="stylesheet" type="text/css" media="all" href="css/style.css">
    <script type="text/javascript" src="js/jquery-1.9.1.min.js"></script>
    <script type="text/javascript" src="js/jquery.onlinedocview.js"></script>
    <script type="text/javascript">
        $(document).ready(function () {
                $("#controls").viewer();
        });
    </script>
</head>
<body>
    <div>
        <div id="Div1">
            <h1>Online Document Viewer Demo</h1>
            <div id="controls">
                <div id="backpage" class="ios-arrow-left">Back</div>
                <div id="forwardpage" class="ios-arrow-right">Forward</div>
            </div>
            <div id="doccontainer">
                <img src="img/1.jpg" data-page="1" title="click for next page"></div>
        </div><!-- END #content -->
    </div><!-- END # -->
</body>

圖1 index頁面

上面，我們定義了index.html頁面，引用了jQuery庫檔案，在controls元素中包含backpage和forwardpage控制元件元素，它用於表示前或後翻頁的操作；而doccontainer中img的元素用於顯示文件，每當使用者點選前或後翻頁就會載入相應的內容到img元素中。

Javascript

接下來，我們需要實現線上文件的翻頁功能和內容的動態載入，我們定義jQuery外掛方法viewer()，當使用者點選#backpage和#forwardpage控制元件元素時實現向前或後翻頁並且動態地載入相應的文件，具體定義如下：

/*****
* The viewer function, when user click #forwardpage, #backpage or image directly,
* load the corrosponding image.
******/
$.fn.viewer = function(options) {
    'use strict';

    var opts = $.extend(true, {}, $.fn.viewer.defaults, options);

    var $docImage = $('#doccontainer > img');

    // Implements the image click function.
    $docImage.on('click', function(e) {
        e.preventDefault();
        var currentId = $(this).attr('data-page'),
        // Gets next page id.
                nextImgId = parseInt(currentId) + 1,
                nextImgSrc = opts.imgDirectory;

        if (currentId == opts.lastDocNum) {
            // If the last page, then do nothing
            return false;
        }

        nextImgSrc += getFile(nextImgId);
        $(this).attr('data-page', nextImgId);
        $(this).attr('src', nextImgSrc);
    })

    // Implements #forwardpage and #backpage control click function.
    $('#controls > #forwardpage, #controls > #backpage').on('click', function(e) {
        e.preventDefault();

        var currentId = $docImage.attr('data-page'),
                nextImgSrc = opts.imgDirectory;

        if ($(this).attr('id') == 'backpage') {
            var nextImgId = parseInt(currentId) - 1;
        } else if ($(this).attr('id') == 'forwardpage') {
            var nextImgId = parseInt(currentId) + 1;
        }

        if ((currentId == opts.lastDocNum && $(this).attr('id') == 'forwardPage') ||
                (currentId == 1 && $(this).attr('id') == 'backpage')) {
            // If the last page or the first page, then do nothing.
            return false;
        }

        // Loads corresponding image file.
        nextImgSrc += getFile(nextImgId);
        $docImage.attr('data-page', nextImgId);
        $docImage.attr('src', nextImgSrc);

    })

    // Constructs the image file name.
    function getFile(n) {
        return n + '.' + opts.fileType;
    }

};

上面，我們定義了jQuery方法viewer()，我們實現了#forwardpage、#backpage和#doccontainer的點選事件處理方法，當使用者點選#forwardpage、#backpage或#doccontainer動態地載入相應的文件，我們通過修改img元素的src屬性來動態載入文件，並且通過data-page屬性儲存當前文件的頁碼。

CSS樣式

最後，我們給#forwardpage和#backpage控制元件元素新增CSS樣式，具體化定義如下：

/*Back and Forward button style*/
.ios-arrow-left {
    cursor:pointer;
    display : block; 
    position:absolute;
    z-index : 0;
    left:50px;
    top:50px;    
    height:30px;
    width:auto;
    padding: 0 10px 0 6px;
    background-repeat:repeat-x;
    background-size : 100% 30px;
    background-position :0;
    background-image : -webkit-linear-gradient(
        bottom,
        rgba(0,0,0,0) 0%,
        rgba(0,0,0,0) 50%,
        rgba(255,255,255,0.1) 50%,
        rgba(255,255,255,0.3) 100%
        );
    border-radius: 5px;
    border-bottom: 1px solid rgba(255,255,255,0.4);
    box-shadow :0 -1px 1px rgba(0,0,0,0.2)inset,
                0 1px 2px rgba(0,0,0,0.8)inset;
    font-family : HelveticaNeue;
    font-weight: 400;
    font-size : 12px;
    line-height : 30px;
    text-align:center;
    color:#fff;
    text-shadow : 0px -1px 0px rgba(0,0,0,0.8);
}
.ios-arrow-left:before{
    position:absolute;
    content : ' ';
    left:-8px;
    top:3.5px;
    height : 24px;
    width: 24px;
    z-index : 1;
    background-repeat:repeat-x;
    background-size : 20px 20px;
    background-position :-1px -0.5px;
    background-image :  
        -webkit-gradient(linear, left bottom, right top, 
            from(rgba(0,0,0,0)), 
            color-stop(0.5, rgba(0,0,0,0)), 
            color-stop(0.5, rgba(255,255,255,0.1)), 
            to(rgba(255,255,255,0.3))); 
    -webkit-transform : rotate(-45deg) skew(-10deg, -10deg);
    border-top-right-radius : 10px;
    border-top-left-radius :0px;
    border-bottom-right-radius : 0px;
    border-bottom-left-radius : 10px;
    border-left : 1.5px solid rgba(255,255,255,0.4);
    box-shadow :  1px 1px 1px rgba(0,0,0,0.4) inset,
        -1px 1px 1px rgba(0,0,0,0.5) inset;
    -webkit-mask-image : 
        -webkit-gradient(linear, left top, right bottom,
            from(#000000), 
            color-stop(0.4,#000000), 
            color-stop(0.5, transparent), 
            to(transparent));
}

.ios-arrow-right {
    cursor:pointer;
    display : block; 
    position:absolute;
    z-index : 0;
    right:50px;
    top:50px;    
    height:30px;
    width:auto;
    padding: 0 6px 0 10px;
    background-repeat:repeat-x;
    background-size : 100% 30px;
    background-position :0;
    background-image : -webkit-linear-gradient(
        bottom,
        rgba(0,0,0,0) 0%,
        rgba(0,0,0,0) 50%,
        rgba(255,255,255,0.1) 50%,
        rgba(255,255,255,0.3) 100%
        );
    border-radius: 5px;
    border-bottom: 1px solid rgba(255,255,255,0.4);
    box-shadow :0 -1px 1px rgba(0,0,0,0.2)inset,
                0 1px 2px rgba(0,0,0,0.8)inset;
    font-family : HelveticaNeue;
    font-weight: 400;
    font-size : 12px;
    line-height : 30px;
    text-align:center;
    color:#fff;
    text-shadow : 0px -1px 0px rgba(0,0,0,0.8);
}
.ios-arrow-right:after{
    position:absolute;
    content : ' ';
    right:-7.5px;
    top:3px;
    height : 24px;
    width: 24px;
    z-index : 1;
    background-repeat:repeat-x;
    background-size : 20px 20px;
    background-position :-1px -0.5px;
    background-image :  
        -webkit-gradient(linear, left bottom, right top, 
            from(rgba(255,255,255,0.3)), 
             color-stop(0.5, rgba(255,255,255,0.1)), 
           color-stop(0.5, rgba(0,0,0,0)), 
            to(rgba(0,0,0,0))); 
    -webkit-transform : rotate(135deg) skew(-10deg, -10deg);
    border-top-right-radius : 10px;
    border-top-left-radius :0px;
    border-bottom-right-radius : 0px;
    border-bottom-left-radius : 10px;
    border-top : 1.5px solid rgba(255,255,255,0.4);
    box-shadow :  1px 1px 1px rgba(0,0,0,0.5) inset,
        -1px 1px 1px rgba(0,0,0,0.4) inset;
    -webkit-mask-image : 
        -webkit-gradient(linear, left top, right bottom,
            from(#000000), 
            color-stop(0.4,#000000), 
            color-stop(0.5, transparent), 
            to(transparent));
}

.ios-arrow-right,
.ios-arrow-right:after,
.ios-arrow-left,
.ios-arrow-left:before {
    background-color: rgba(33,33,33,1);/*normalcolor*/
}

.ios-arrow-right:hover,
.ios-arrow-right:hover:after,
.ios-arrow-left:hover,
.ios-arrow-left:hover:before {
    background-color: rgba(0,0,0,1);/*hovercolor*/
}

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