15个开发常用的jQuery代码片段

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");

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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

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

$(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  });

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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>

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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非死book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);  });

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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);  })  })  })

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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");  });

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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      });  });

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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;    });  };

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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;      }    });  });

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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("");  });

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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; }); 

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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);

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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);  });

来自： codegeekz