Jquery高亮显示文本中重要的关键字

一、界面预览



鼠标放到右边的Tab按钮上，文字透明度降低，同时一段文字高亮显示，效果如下：



Demo地址：http://5thirtyone.com/sandbox/samples/fadefocus/
很绚丽的效果幺！
二、实现原理

将要高亮显示的文字加上<span>段落标记， class=”mask”的div 做为遮罩层，使此遮罩层位于文字内容之上（z-index属性，使用Jquery给段落动态添加样式类。

三、HTML代码

[align=left]<div class="wrapper">[/align] [align=left] <ul class="entity-results">[/align] [align=left] <li><a class="d1" href="#">Summary</a></li>[/align] [align=left] <li><a class="d2" href="#">Avatar</a></li>[/align] [align=left] <li><a class="d3" href="#">Formats</a></li>[/align] [align=left] </ul>[/align] [align=left] <div class="content">[/align] [align=left] <h2>[/align] [align=left] Avatar (2009 film)</h2>[/align] [align=left] <div class="entity-source">[/align] [align=left] <img src="images/avatar.jpg" alt="Avatar poster" />[/align] [align=left] <p>[/align] [align=left] Avatar, also known as James Cameron's Avatar, is an American 3-D science fiction[/align] [align=left] epic film written and directed by <a href="http://en.wikipedia.org/wiki/James_Cameron">[/align] [align=left] James Cameron</a>, and was released on December 16, 2009 by 20th Century Fox.[/align] [align=left] The film is co-produced by <a href="http://en.wikipedia.org/wiki/Lightstorm_Entertainment">[/align] [align=left] Lightstorm Entertainment</a>, and <span class="d1">focuses on an epic conflict on Pandora</span>,[/align] [align=left] an inhabited Earth-sized moon of Polyphemus, one of three fictional gas giants orbiting[/align] [align=left] <a href="http://en.wikipedia.org/wiki/Alpha_Centauri_A">Alpha Centauri A</a>. On[/align] [align=left] Pandora, human colonists and the sentient humanoid indigenous inhabitants of Pandora,[/align] [align=left] the Na'vi, engage in a war over the planet's resources and the latter's continued[/align] [align=left] existence. The film's title refers to <span class="d2">an avatar, a representation of[/align] [align=left] a real person in a virtual world</span>.</p>[/align] [align=left] <p>[/align] [align=left] <span class="d3">The film was released in 2D and 3D formats</span>, along with an[/align] [align=left] IMAX 3D release in selected theaters. The film is being touted as a breakthrough[/align] [align=left] in terms of filmmaking technology, for its development of 3D viewing and stereoscopic[/align] [align=left] filmmaking with cameras that were specially designed for the film's production.</p>[/align] [align=left] <p>[/align] [align=left] Read the rest of the <a href="http://en.wikipedia.org/wiki/Avatar_(2009_film)">original[/align] [align=left] Wikipedia page about Avatar</a></p>[/align] [align=left] <div class="mask">[/align] [align=left] </div>[/align] [align=left] </div>[/align] [align=left] </div>[/align] [align=left]</div>[/align]

entity-results类中显示了Tab按钮，每个按钮控制左边文字的透明度，段落文字的高亮显示。
entity-source类中有三个段落span Calss分别为 d1 d2 d3，也就是高亮文字段落。
class=”mask”的空div放到最后，此Div也就是一个遮罩层。
四、CSS关键代码

[align=left].entity-source, .entity-source span.show[/align] [align=left]{[/align] [align=left] position: relative;[/align] [align=left]}[/align] [align=left].entity-source .mask[/align] [align=left]{[/align] [align=left] display: none;[/align] [align=left] position: absolute;[/align] [align=left] top: 0;[/align] [align=left] left: 0;[/align] [align=left] height: 100%;[/align] [align=left] width: 100%;[/align] [align=left] z-index: 1;[/align] [align=left]}[/align] [align=left].entity-source span[/align] [align=left]{[/align] [align=left] z-index: 2;[/align] [align=left]}[/align] [align=left].entity-source span.show[/align] [align=left]{[/align] [align=left] background: #ffc;[/align] [align=left] color: #000;[/align] [align=left]}[/align]

类mask中的z-index:1 使得<div class=”mask”> 覆盖在左边文字内容之上。
z-nidex：2又使得span段落覆盖在<div class=”mask”>之上。从而显示实现了段落文字高亮显示。
五、Jquery代码

[align=left]jQuery(document).ready(function($) {[/align] [align=left] // mask source 控制mask的动画效果[/align] [align=left] var maskSource = jQuery('.mask');[/align] [align=left] jQuery('.entity-results').hover(function() {[/align] [align=left] maskSource.animate({opacity:0.7},1).fadeIn('750');[/align] [align=left] }, function() {[/align] [align=left] maskSource.fadeOut('1000');[/align] [align=left] });[/align] [align=left] [/align] [align=left] // match hover 控制段落的高亮显示[/align] [align=left] var sample1 = jQuery('span.d1');[/align] [align=left] var sample2 = jQuery('span.d2');[/align] [align=left] var sample3 = jQuery('span.d3');[/align] [align=left] jQuery('a.d1').hover(function() {[/align] [align=left] sample1.addClass('show'); //给段落添加类[/align] [align=left] }, function() {[/align] [align=left] sample1.removeClass('show'); //移除段落类[/align] [align=left] });[/align] [align=left] jQuery('a.d2').hover(function() {[/align] [align=left] sample2.addClass('show');[/align] [align=left] }, function() {[/align] [align=left] sample2.removeClass('show');[/align] [align=left] });[/align] [align=left] jQuery('a.d3').hover(function() {[/align] [align=left] sample3.addClass('show');[/align] [align=left] }, function() {[/align] [align=left] sample3.removeClass('show');[/align] [align=left] });[/align] });

动画函数animate(params, [duration], [easing], [callback])
Params：一组包含作为动画属性和终值的样式属性和及其值的集合
duration (可选)：种预定速度之一的字符串("slow", "normal", or "fast")或表示动画时长的毫秒数值(如：1000)
easing (可选)：要使用的擦除效果的名称(需要插件支持).默认jQuery提供"linear" 和 "swing".
callback (可选)：在动画完成时执行的函数

淡入效果函数：fadeIn(speed, [callback])
Speed：三种预定速度之一的字符串("slow", "normal", or "fast")或表示动画时长的毫秒数值(如：1000)
callback (可选)：(Optional) 在动画完成时执行的函数

淡出效果函数：fadeOut解释同fadeIn