jQuery高亮显示文本中重要的关键字

本文介绍鼠标放到右边的Tab按钮上，文字透明度降低，同时一段文字高亮显示的效果，对于查询、文本分析的应用场景有很好的参考作用，有需要的朋友来看看吧。

一、先看效果，界面预览：

将鼠标放到右边的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：

二、实现原理

  将要高亮显示的文字加上段落标记， 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

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

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

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

类mask中的z-index:1 使得
”mask”> 覆盖在左边文字内容之上。

z-nidex：2又使得span段落覆盖在
”mask”>之上。从而显示实现了段落文字高亮显示。

五、Jquery代码

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

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