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。
本文收集了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。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);
- });