jQuery里提供了许多创建交互式网站的方法，在开发Web项目时，开发人员应该好好利用jQuery代码，它们不仅能给网站带来各种动画、特效，还会提高网站的用户体验。

下面就让我们一起来享受jQuery代码的魅力之处吧。

1.预加载图片

(function($) {

var cache = [];

// Arguments are image paths relative to the current page.

$.preLoadImages = function() {

var args_len = arguments.length;

for (var i = args_len; i--;) {

var cacheImage = document.createElement('img');

cacheImage.src = arguments[i];

cache.push(cacheImage);

}

}

jQuery.preLoadImages("image1.gif", "/path/to/image2.png");

2. 让页面中的每个元素都适合在移动设备上展示

var scr = document.createElement('script');

scr.setAttribute('src', 'https://ajax.googleapis.com/ajax/libs/jquery/1.5.2/jquery.min.js');

document.body.appendChild(scr);

scr.onload = function(){

$('div').attr('class', '').attr('id', '').css({

'margin' : 0,

'padding' : 0,

'width': '100%',

'clear':'both'

});

};

3.图像等比例缩放

$(window).bind("load", function() {

// IMAGE RESIZE

$('#product_cat_list img').each(function() {

var maxWidth = 120;

var maxHeight = 120;

var ratio = 0;

var width = $(this).width();

var height = $(this).height();

if(width > maxWidth){

ratio = maxWidth / width;

$(this).css("width", maxWidth);

$(this).css("height", height * ratio);

height = height * ratio;

}

var width = $(this).width();

var height = $(this).height();

if(height > maxHeight){

ratio = maxHeight / height;

$(this).css("height", maxHeight);

$(this).css("width", width * ratio);

width = width * ratio;

}

});

//$("#contentpage img").show();

// IMAGE RESIZE

});

4.返回页面顶部

// Back To Top

$(document).ready(function(){

$('.top').click(function() {

$(document).scrollTo(0,500);

});

});

//Create a link defined with the class .top

<a href="#" class="top">Back To Top</a>

5.使用jQuery打造手风琴式的折叠效果

var accordion = {

init: function(){

var $container = $('#accordion');

$container.find('li:not(:first) .details').hide();

$container.find('li:first').addClass('active');

$container.on('click','li a',function(e){

e.preventDefault();

var $this = $(this).parents('li');

if($this.hasClass('active')){

if($('.details').is(':visible')) {

$this.find('.details').slideUp();

} else {

$this.find('.details').slideDown();

}

} else {

$container.find('li.active .details').slideUp();

$container.find('li').removeClass('active');

$this.addClass('active');

$this.find('.details').slideDown();

}

});

}

};

6.通过预加载图片廊中的上一幅下一幅图片来模仿Facebook的图片展示方式

var nextimage = "/images/some-image.jpg";

$(document).ready(function(){

window.setTimeout(function(){

var img = $("").attr("src", nextimage).load(function(){

//all done

});

}, 100);

});

7.使用jQuery和Ajax自动填充选择框

$(function(){

$("select#ctlJob").change(function(){

$.getJSON("/select.php",{id: $(this).val(), ajax: 'true'}, function(j){

var options = '';

for (var i = 0; i < j.length; i++) {

options += '

' + j[i].optionDisplay + '

';

}

$("select#ctlPerson").html(options);

})

})

})

8.自动替换丢失的图片

// Safe Snippet

$("img").error(function () {

$(this).unbind("error").attr("src", "missing_image.gif");

});

// Persistent Snipper

$("img").error(function () {

$(this).attr("src", "missing_image.gif");

});

9.在鼠标悬停时显示淡入/淡出特效

$(document).ready(function(){

$(".thumbs img").fadeTo("slow", 0.6); // This sets the opacity of the thumbs to fade down to 60% when the page loads

$(".thumbs img").hover(function(){

$(this).fadeTo("slow", 1.0); // This should set the opacity to 100% on hover

},function(){

$(this).fadeTo("slow", 0.6); // This should set the opacity back to 60% on mouseout

});

});

10.清空表单数据

function clearForm(form) {

// iterate over all of the inputs for the form

// element that was passed in

$(':input', form).each(function() {

var type = this.type;

var tag = this.tagName.toLowerCase(); // normalize case

// it's ok to reset the value attr of text inputs,

// password inputs, and textareas

if (type == 'text' || type == 'password' || tag == 'textarea')

this.value = "";

// checkboxes and radios need to have their checked state cleared

// but should *not* have their 'value' changed

else if (type == 'checkbox' || type == 'radio')

this.checked = false;

// select elements need to have their 'selectedIndex' property set to -1

// (this works for both single and multiple select elements)

else if (tag == 'select')

this.selectedIndex = -1;

});

};

11.预防对表单进行多次提交

$(document).ready(function() {

$('form').submit(function() {

if(typeof jQuery.data(this, "disabledOnSubmit") == 'undefined') {

jQuery.data(this, "disabledOnSubmit", { submited: true });

$('input[type=submit], input[type=button]', this).each(function() {

$(this).attr("disabled", "disabled");

});

return true;

}

else

{

return false;

}

});

});

12.动态添加表单元素

//change event on password1 field to prompt new input

$('#password1').change(function() {

//dynamically create new input and insert after password1

$("#password1").append("");

});

13.让整个Div可点击

blah blah blah. link

The following lines of jQuery will make the entire div clickable: $(".myBox").click(function(){ window.location=$(this).find("a").attr("href"); return false; });

14.平衡高度或Div元素

var maxHeight = 0;

$("div").each(function(){

if ($(this).height() > maxHeight) { maxHeight = $(this).height(); }

});

$("div").height(maxHeight);

15. 在窗口滚动时自动加载内容

var loading = false;

$(window).scroll(function(){

if((($(window).scrollTop()+$(window).height())+250)>=$(document).height()){

if(loading == false){

loading = true;

$('#loadingbar').css("display","block");

$.get("load.php?start="+$('#loaded_max').val(), function(loaded){

$('body').append(loaded);

$('#loaded_max').val(parseInt($('#loaded_max').val())+50);

$('#loadingbar').css("display","none");

loading = false;

});

}

}

});

$(document).ready(function() {

$('#loaded_max').val(50);

});

本文收集的这15段非常实用的jQuery代码片段，你可以直接复制黏贴到代码里，但请开发者注意了，要理解代码再使用哦。