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="#">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