jQuery 15个精彩片断

jQuery 15个精彩片段
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"); 

　　源码

　　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'    });}; 

　　源码

　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}); 

　　源码

　　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="#" name="code">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);}); 

　　源码

　　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);})})}) 

　　源码

　　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");}); 

　　源码

　　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    });}); 

　　源码

　　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;  });}; 

　　源码

　　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;    }  });}); 

　　源码

　　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("");}); 

　　源码

　　13.让整个Div可点击

 blah blah blah. linkThe following lines of jQuery will make the entire div clickable: $(".myBox").click(function(){ window.location=$(this).find("a").attr("href"); return false; }); 

　　源码

　　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); 

　　源码

　　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);}); 

查看更多 下一篇