可以直接拿来用的15个jQuery代码片段

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

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(function($) {   varcache = [];   // Arguments are image paths relative to the current page.   $.preLoadImages =function() {     varargs_len = arguments.length;     for(vari = args_len; i--;) {       varcacheImage = document.createElement('img');       cacheImage.src = arguments[i];       cache.push(cacheImage);     }   } jQuery.preLoadImages("image1.gif","/path/to/image2.png");

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2. 让页面中的每个元素都适合在移动设备上展示

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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'     }); };

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3.图像等比例缩放

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$(window).bind("load",function() {     // IMAGE RESIZE     $('#product_cat_list img').each(function() {         varmaxWidth = 120;         varmaxHeight = 120;         varratio = 0;         varwidth = $(this).width();         varheight = $(this).height();         if(width > maxWidth){             ratio = maxWidth / width;             $(this).css("width", maxWidth);             $(this).css("height", height * ratio);             height = height * ratio;         }         varwidth = $(this).width();         varheight = $(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 });

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4.返回页面顶部

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// 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>

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5.使用jQuery打造手风琴式的折叠效果

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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

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var nextimage = "/images/some-image.jpg"; $(document).ready(function(){ window.setTimeout(function(){ var img = $("").attr("src", nextimage).load(function(){ //all done }); }, 100); });

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7.使用jQuery和Ajax自动填充选择框

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$(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); }) }) })

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8.自动替换丢失的图片

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// Safe Snippet $("img").error(function() {     $(this).unbind("error").attr("src","missing_image.gif"); }); // Persistent Snipper $("img").error(function() {     $(this).attr("src","missing_image.gif"); });

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9.在鼠标悬停时显示淡入/淡出特效

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$(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     }); });

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10.清空表单数据

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function clearForm(form) {   // iterate over all of the inputs for the form   // element that was passed in   $(':input', form).each(function() {     vartype =this.type;     vartag =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;   }); };

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11.预防对表单进行多次提交

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$(document).ready(function() {   $('form').submit(function() {     if(typeofjQuery.data(this,"disabledOnSubmit") =='undefined') {       jQuery.data(this,"disabledOnSubmit", { submited:true });       $('input[type=submit], input[type=button]',this).each(function() {         $(this).attr("disabled","disabled");       });       returntrue;     }     else     {       returnfalse;     }   }); });

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12.动态添加表单元素

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//change event on password1 field to prompt new input $('#password1').change(function() {         //dynamically create new input and insert after password1         $("#password1").append(""); });

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13.让整个Div可点击

1 2	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");returnfalse; });

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14.平衡高度或Div元素

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var maxHeight = 0; $("div").each(function(){    if($(this).height() > maxHeight) { maxHeight = $(this).height(); } }); $("div").height(maxHeight);

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15. 在窗口滚动时自动加载内容

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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); });