可以直接拿来用的15个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");



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); });
原文地址:https://www.cnblogs.com/seanjack/p/6295072.html