Bootstrap - Plugin Scrollspy
Il plug-in Scroll spia (aggiornamento automatico di navigazione) consente di scegliere come target le sezioni della pagina in base alla posizione di scorrimento. Nella sua implementazione di base, mentre scorri, puoi aggiungere.active classi alla barra di navigazione in base alla posizione di scorrimento.
Se desideri includere questa funzionalità di plugin individualmente, allora avrai bisogno di scrollspy.js. Altrimenti, come menzionato nel capitolo Panoramica sui plug-in Bootstrap , puoi includere bootstrap.js o bootstrap.min.js minimizzato .
Utilizzo
Puoi aggiungere un comportamento scrollspy alla tua barra di navigazione in alto -
Via data attributes - aggiungi data-spy = "scroll"all'elemento che vuoi spiare (tipicamente il corpo). Quindi aggiungi l'attributodata-target con l'ID o la classe dell'elemento genitore di qualsiasi Bootstrap .navcomponente. Affinché funzioni, devi avere elementi nel corpo della pagina con ID corrispondenti dei link che stai spiando.
<body data-spy = "scroll" data-target = ".navbar-example">
...
<div class = "navbar-example">
<ul class = "nav nav-tabs">
...
</ul>
</div>
...
</body>Via JavaScript - È possibile richiamare lo scrollspy con JavaScript invece di utilizzare gli attributi dei dati, selezionando l'elemento da spiare e quindi invocando il .scrollspy() funzione -
$('body').scrollspy({ target: '.navbar-example' })Esempio
Il seguente esempio mostra l'uso del plugin scrollspy tramite attributi di dati -
<nav id = "navbar-example" class = "navbar navbar-default navbar-static" role = "navigation">
<div class = "navbar-header">
<button class = "navbar-toggle" type = "button" data-toggle = "collapse"
data-target = ".bs-js-navbar-scrollspy">
<span class = "sr-only">Toggle navigation</span>
<span class = "icon-bar"></span>
<span class = "icon-bar"></span>
<span class = "icon-bar"></span>
</button>
<a class = "navbar-brand" href = "#">Tutorial Name</a>
</div>
<div class = "collapse navbar-collapse bs-js-navbar-scrollspy">
<ul class = "nav navbar-nav">
<li><a href = "#ios">iOS</a></li>
<li><a href = "#svn">SVN</a></li>
<li class = "dropdown">
<a href = "#" id = "navbarDrop1" class = "dropdown-toggle" data-toggle = "dropdown">
Java
<b class = "caret"></b>
</a>
<ul class = "dropdown-menu" role = "menu" aria-labelledby = "navbarDrop1">
<li><a href = "#jmeter" tabindex = "-1">jmeter</a></li>
<li><a href = "#ejb" tabindex = "-1">ejb</a></li>
<li class = "divider"></li>
<li><a href = "#spring" tabindex = "-1">spring</a></li>
</ul>
</li>
</ul>
</div>
</nav>
<div data-spy = "scroll" data-target = "#navbar-example" data-offset = "0"
style = "height:200px; overflow:auto; position: relative;">
<h4 id = "ios">iOS</h4>
<p>iOS is a mobile operating system developed and distributed by Apple
Inc. Originally released in 2007 for the iPhone, iPod Touch, and Apple
TV. iOS is derived from OS X, with which it shares the Darwin
foundation. iOS is Apple's mobile version of the OS X operating system
used on Apple computers.</p>
<h4 id = "svn">SVN</h4>
<p>Apache Subversion which is often abbreviated as SVN, is a software
versioning and revision control system distributed under an open source
license. Subversion was created by CollabNet Inc. in 2000, but now it
is developed as a project of the Apache Software Foundation, and as
such is part of a rich community of developers and users.</p>
<h4 id = "jmeter">jMeter</h4>
<p>jMeter is an Open Source testing software. It is 100% pure Java
application for load and performance testing.</p>
<h4 id = "ejb">EJB</h4>
<p>Enterprise Java Beans (EJB) is a development architecture for building
highly scalable and robust enterprise level applications to be deployed
on J2EE compliant Application Server such as JBOSS, Web Logic etc.</p>
<h4 id = "spring">Spring</h4>
<p>Spring framework is an open source Java platform that provides
comprehensive infrastructure support for developing robust Java
applications very easily and very rapidly.</p>
<p>Spring framework was initially written by Rod Johnson and was first
released under the Apache 2.0 license in June 2003.</p>
</div>Opzioni
Le opzioni possono essere passate tramite attributi di dati o JavaScript. La tabella seguente elenca le opzioni:
| Nome opzione | Tipo / valore predefinito | Nome attributo dati | Descrizione |
|---|---|---|---|
| compensare | numero predefinito: 10 | data-offset | Pixel da spostare dall'alto quando si calcola la posizione di scorrimento. |
Metodi
.scrollspy('refresh') - Quando si chiama lo scrollspy tramite il metodo JavaScript, è necessario chiamare il file .refreshmetodo per aggiornare il DOM. Questo è utile se qualche elemento del DOM è cambiato, cioè se hai aggiunto o rimosso alcuni elementi. Di seguito sarebbe la sintassi per utilizzare questo metodo.
$('[data-spy = "scroll"]').each(function () {
var $spy = $(this).scrollspy('refresh')
})Esempio
Il seguente esempio dimostra l'uso di .scrollspy('refresh') metodo -
<nav id = "myScrollspy" class = "navbar navbar-default navbar-static" role = "navigation">
<div class = "navbar-header">
<button class = "navbar-toggle" type = "button" data-toggle = "collapse"
data-target = ".bs-js-navbar-scrollspy">
<span class = "sr-only">Toggle navigation</span>
<span class = "icon-bar"></span>
<span class = "icon-bar"></span>
<span class = "icon-bar"></span>
</button>
<a class = "navbar-brand" href = "#">Tutorial Name</a>
</div>
<div class = "collapse navbar-collapse bs-js-navbar-scrollspy">
<ul class = "nav navbar-nav">
<li class = "active"><a href = "#ios">iOS</a></li>
<li><a href = "#svn">SVN</a></li>
<li class = "dropdown">
<a href = "#" id = "navbarDrop1" class = "dropdown-toggle" data-toggle = "dropdown">
Java
<b class = "caret"></b>
</a>
<ul class = "dropdown-menu" role = "menu" aria-labelledby = "navbarDrop1">
<li><a href = "#jmeter" tabindex = "-1">jmeter</a></li>
<li><a href = "#ejb" tabindex = "-1">ejb</a></li>
<li class = "divider"></li>
<li><a href = "#spring" tabindex = "-1">spring</a></li>
</ul>
</li>
</ul>
</div>
</nav>
<div data-spy = "scroll" data-target = "#myScrollspy" data-offset = "0"
style = "height:200px; overflow:auto; position: relative;">
<div class = "section">
<h4 id = "ios">iOS<small><a href = "#" onclick = "removeSection(this);">
× Remove this section</a></small>
</h4>
<p>iOS is a mobile operating system developed and distributed by
Apple Inc. Originally released in 2007 for the iPhone, iPod Touch, and
Apple TV. iOS is derived from OS X, with which it shares the Darwin
foundation. iOS is Apple's mobile version of the OS X operating system
used on Apple computers.</p>
</div>
<div class = "section">
<h4 id = "svn">SVN<small></small></h4>
<p>Apache Subversion which is often abbreviated as SVN, is a software
versioning and revision control system distributed under an open source
license. Subversion was created by CollabNet Inc. in 2000, but
now it is developed as a project of the Apache Software Foundation,
and as such is part of a rich community of developers and users.</p>
</div>
<div class = "section">
<h4 id = "jmeter">jMeter<small><a href = "#" onclick = "removeSection(this);">
× Remove this section</a></small>
</h4>
<p>jMeter is an Open Source testing software. It is 100% pure Java
application for load and performance testing.</p>
</div>
<div class = "section">
<h4 id = "ejb">EJB</h4>
<p>Enterprise Java Beans (EJB) is a development architecture for
building highly scalable and robust enterprise level applications
to be deployed on J2EE compliant Application Server such as
JBOSS, Web Logic etc.</p>
</div>
<div class = "section">
<h4 id = "spring">Spring</h4>
<p>Spring framework is an open source Java platform that provides
comprehensive infrastructure support for developing robust Java
applications very easily and very rapidly.</p>
<p>Spring framework was initially written by Rod Johnson and was first
released under the Apache 2.0 license in June 2003.</p>
</div>
</div>
<script type = "text/javascript">
$(function(){
removeSection = function(e) {
$(e).parents(".section").remove();
$('[data-spy = "scroll"]').each(function () {
var $spy = $(this).scrollspy('refresh')
});
}
$("#myScrollspy").scrollspy();
});
</script>Eventi
La tabella seguente elenca gli eventi su cui lavorare con scrollspy. Questo evento può essere utilizzato per agganciarsi alla funzione.
| Evento | Descrizione | Esempio |
|---|---|---|
| attivare.bs.scrollspy | Questo evento si attiva ogni volta che un nuovo elemento viene attivato dallo scrollspy. | |
Esempio
Il seguente esempio dimostra l'uso di activate.bs.scrollspy evento -
<html>
<head>
<link rel = "stylesheet" href = "bootstrap/css/bootstrap.min.css">
<script src = "bootstrap/scripts/jquery.min.js"></script>
<script src = "bootstrap/js/bootstrap.min.js"></script>
<script>
$(document).ready(function(){
removeSection = function(e) {
$(e).parents(".subject").remove();
$('[data-spy="scroll"]').each(function () {
var $spy = $(this).scrollspy('refresh')
});
}
$("#Navexample").scrollspy();
// The event is fired when an item gets actived with the scrollspy
$("#Navexample").on('activate.bs.scrollspy', function () {
var currentSection = $(".nav li.active > a").text();
$("#spyevent").html("Current Item being viewed >> " + currentSection);
})
});
</script>
<style>
.scroll-box {
height: 250px;
position: relative;
overflow: auto;
font-size:2em;
}
</style>
</head>
<body>
<div class = "container">
<nav id = "Navexample" class = "navbar navbar-default" role = "navigation">
<!-- Nav Bar -->
<div class = "navbar-header">
<button type = "button" class = "navbar-toggle"
data-toggle = "collapse" data-target = "#navbarCollapse">
<span class = "sr-only">Toggle navigation</span>
<span class = "icon-bar"></span>
<span class = "icon-bar"></span>
<span class = "icon-bar"></span>
</button>
<a class = "navbar-brand" href = "#">Tutorials Point</a>
</div>
<!-- Links and Sublinks -->
<div class = "collapse navbar-collapse" id = "navbarCollapse">
<ul class = "nav navbar-nav">
<li class = "active"><a href = "#subject-1">Subject 1</a></li>
<li><a href = "#subject-2">Subject 2</a></li>
<li class = "dropdown"><a href = "#" class = "dropdown-toggle"
data-toggle = "dropdown">Subject 3<b class = "caret"></b></a>
<ul class = "dropdown-menu">
<li><a href = "#subject-3-1">Subject 3.1</a></li>
<li><a href = "#subject-3-2">Subject 3.2</a></li>
<li><a href = "#subject-3-3">Subject 3.3</a></li>
</ul>
</li>
<li><a href = "#subject-4">Subject 4</a></li>
</ul>
</div>
</nav>
<div class = "scroll-box" data-spy = "scroll" data-offset = "0">
<div class = "subject">
<h3 id = "subject-1">Subject 1
<small><a href = "#" onclick = "removeSubject(this);">Remove Subject ×</a></small>
</h3>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit,
sed do eiusmod tempor incididunt ut labore et dolore magna
aliqua. Ut enim ad minim veniam, quis nostrud exercitation
ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
<hr>
<div class = "subject">
<h3 id = "subject-2">Subject 2
<small><a href = "#" onclick = "removeSubject(this);">Remove Subject ×</a></small>
</h3>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit,
sed do eiusmod tempor incididunt ut labore et dolore magna
aliqua. Ut enim ad minim veniam, quis nostrud exercitation
ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
<hr>
<div class = "subject">
<h3 id = "subject-3">Subject 3
<small><a href = "#" onclick = "removeSubject(this);"> Remove Subject ×</a></small>
</h3>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit,
sed do eiusmod tempor incididunt ut labore et dolore magna
aliqua. Ut enim ad minim veniam, quis nostrud exercitation
ullamco laboris nisi ut aliquip ex ea commodo consequat.</p><
</div>
<hr>
<div class = "subject">
<h4 id = "subject-3-1">Subject 3.1
<small><a href = "#" onclick = "removeSubject(this);"> Remove Subject ×</a></small>
</h4>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit,
sed do eiusmod tempor incididunt ut labore et dolore magna
aliqua. Ut enim ad minim veniam, quis nostrud exercitation
ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
<div class = "subject">
<h4 id = "subject-3-2">Subject 3.2
<small><a href = "#" onclick = "removeSubject(this);"> Remove Subject ×</a></small>
</h4>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit,
sed do eiusmod tempor incididunt ut labore et dolore magna
aliqua. Ut enim ad minim veniam, quis nostrud exercitation
ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
<div class = "subject">
<h4 id = "subject-3-3">Subject 3.3
<small><a href = "#" onclick = "removeSubject(this);">Remove Subject ×</a></small>
</h4>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit,
sed do eiusmod tempor incididunt ut labore et dolore magna
aliqua. Ut enim ad minim veniam, quis nostrud exercitation
ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
<hr>
<div class = "subject">
<h3 id = "subject-4">Subject 4
<small><a href = "#" onclick = "removeSubject(this);">Remove Subject ×</a></small>
</h3>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit,
sed do eiusmod tempor incididunt ut labore et dolore magna
aliqua. Ut enim ad minim veniam, quis nostrud exercitation
ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
</div>
<hr>
<h4 id = "spyevent" class = "text-info"></h4>
</div>
</body>
</html>