25个实用的jquery技巧

1. 去除页面的右键菜单 
 
 
$(document).ready(function(){ $(document).bind(“contextmenu”,function(e){returnfalse;});}); 
2、搜索输入框文字的消失 
 
 
当鼠标获得焦点、失去焦点的时候，input输入框文字处理： 
 
 
$(document).ready(function(){ $(“input.text1″).val(“Enter your search text here”); textFill($(‘input.text1′));});function textFill(input){//input focus text function var originalvalue = input.val(); input.focus(function(){if( $.trim(input.val())== originalvalue ){ input.val(”);}}); input.blur(function(){if( $.trim(input.val())==”){ input.val(originalvalue);}});} 
3、新窗口打开页面 
 
 
$(document).ready(function(){//Example 1: Every link will open in a new window $(‘a[href^="http://"]‘).attr(“target”,”_blank”);   //Example 2: Links with the rel=”external” attribute will only open in a new window $(‘a[@rel$='external']‘).click(function(){this.target=”_blank”;});}); 
// how to use 
 
 
<a href=”http://www.opensourcehunter.com” rel=”external”>open link</a> 
4、判断浏览器类型 
 
 
注意： jQuery 1.4中$.support 来代替以前的$.browser 
 
 
$(document).ready(function(){// Target Firefox 2 and above if($.browser.mozilla&& $.browser.version>=”1.8″){// do something }// Target Safari if( $.browser.safari){// do something }// Target Chrome if( $.browser.chrome){// do something }// Target Camino if( $.browser.camino){// do something }// Target Opera if( $.browser.opera){// do something }// Target IE6 and below if($.browser.msie&& $.browser.version<=6){// do something }// Target anything above IE6 if($.browser.msie&& $.browser.version>6){// do something }}); 
5、预加载图片 
 
 
$(document).ready(function(){ jQuery.preloadImages=function(){for(var i =0; i<arguments.length; i++)=”"{=”" jquery(“=”"><img>”).attr(“src”, arguments);}}// how to use $.preloadImages(“image1.jpg”);});</arguments.length;> 
6、轻松切换css样式 
 
 
$(document).ready(function(){ $(“a.Styleswitcher”).click(function(){//swicth the LINK REL attribute with the value in A REL attribute $(‘link[rel=stylesheet]‘).attr(‘href’, $(this).attr(‘rel’));}); 
// how to use 
 
// place this in your header 
 
 
<link rel=”stylesheet” href=”default.css” type=”text/css”> // the links <a href=”#” rel=”default.css”>Default Theme</a> <a href=”#” class=”Styleswitcher” rel=”red.css”>Red Theme</a> <a href=”#” class=”Styleswitcher” rel=”blue.css”>Blue Theme</a> }); 
7、高度相等的列 
 
 
如果您使用两个CSS列，以此来作为他们完全一样的高度 
 
 
$(document).ready(function(){function equalHeight(group){ tallest =0; group.each(function(){ thisHeight = $(this).height();if(thisHeight > tallest){ tallest = thisHeight;}}); group.height(tallest);}// how to use $(document).ready(function(){ equalHeight($(“.left”)); equalHeight($(“.right”));});}); 
8、简单字体变大缩小 
 
 
$(document).ready(function(){// Reset the font size(back to default) var originalFontSize = $(‘html’).css(‘font-size’); $(“.resetFont”).click(function(){ $(‘html’).css(‘font-size’, originalFontSize);});// Increase the font size(bigger font0 $(“.increaseFont”).click(function(){var currentFontSize = $(‘html’).css(‘font-size’);var currentFontSizeNum = parseFloat(currentFontSize,10);var newFontSize = currentFontSizeNum*1.2; $(‘html’).css(‘font-size’, newFontSize);returnfalse;});// Decrease the font size(smaller font) $(“.decreaseFont”).click(function(){var currentFontSize = $(‘html’).css(‘font-size’);var currentFontSizeNum = parseFloat(currentFontSize,10);var newFontSize = currentFontSizeNum*0.8; $(‘html’).css(‘font-size’, newFontSize);returnfalse;});}); 
9、返回头部滑动动画 
 
 
$(‘a[href*=#]‘).click(function(){if(location.pathname.replace(/^//,”)==this.pathname.replace(/^//,”)&& location.hostname==this.hostname){var $target = $(this.hash); $target = $target.length&& $target || $(‘[name='+this.hash.slice(1)+']‘);if($target.length){var targetOffset = $target.offset().top; $(‘html,body’) .animate({scrollTop: targetOffset},900);returnfalse;}}}); 
// how to use 
 
// place this where you want to scroll to 
 
 
<a name=”top”></a> // the link <a href=”#top”>go to top</a> 
10、获取鼠标位置 
 
 
$().mousemove(function(e){//display the x and y axis values inside the div with the id XY $(‘#XY’).html(“X Axis : “+ e.pageX+” | Y Axis “+ e.pageY);}); 
11、判断一个元素是否为空 
 
 
if($(‘#id’).html()){// do something } 
12、替换元素 
 
 
$(‘#id’).replaceWith(‘ <div>I have been replaced</div>   ‘); 
13、jquery timer 返回函数 
 
 
$(document).ready(function(){ window.setTimeout(function(){// do something },1000);}); 
14、jquery也玩替换 
 
 
$(document).ready(function(){var el = $(‘#id’); el.html(el.html().replace(/word/ig,”"));}); 
15、判断元素是否存在 
 
 
$(document).ready(function(){if($(‘#id’).length){// do something }}); 
16、让div也可以click 
 
 
$(“div”).click(function(){//get the url from href attribute and launch the url window.location=$(this).find(“a”).attr(“href”);returnfalse;}); 
// how to use 
 
 
<div><a href=”index.html”>home</a></div> 
17、使用jquery来判断浏览器大小添加不同的class 
 
 
$(document).ready(function(){function checkWindowSize(){if( $(window).width()>1200){ $(‘body’).addClass(‘large’);}else{ $(‘body’).removeClass(‘large’);}} $(window).resize(checkWindowSize);}); 
18、几个字符就clone！ 
 
 
var cloned = $(‘#id’).clone() 
19、设置div在屏幕中央 
 
 
$(document).ready(function(){ jQuery.fn.center=function(){this.css(“position”,”absolute”);this.css(“top”,( $(window).height()-this.height())/2+$(window).scrollTop()+”px”);this.css(“left”,( $(window).width()-this.width())/2+$(window).scrollLeft()+”px”);returnthis;} $(“#id”).center();}); 
20、创建自己的选择器 
 
 
$(document).ready(function(){ $.extend($.expr[':'],{ moreThen1000px:function(a){return $(a).width()>1000;}}); $(‘.box:moreThen1000px’).click(function(){// creating a simple js alert box alert(‘The element that you have clicked is over 1000 pixels wide’);});}); 
21、计算元素的数目 
 
 
$(document).ready(function(){ $(“p”).size();}); 
22、设置自己的li样式 
 
 
$(document).ready(function(){ $(“ul”).addClass(“Replaced”); $(“ul > li”).prepend(“‒ “);// how to use ul.Replaced{ list-style : none;}}); 
23、使用google的主机来加载jquery库 
 
 
<script src=”http://www.google.com/jsapi”></script> <script type=”text/javascript”> google.load(“jquery”, “1.2.6″); google.setOnLoadCallback(function() { // do something }); </script><script src=”http://ajax.googleapis.com/ajax/libs/jquery/1.2.6/jquery.min.js” type=”text/javascript”></script>   // Example 2:(the best and fastest way) <script type=”text/javascript” src=”http://ajax.googleapis.com/ajax/libs/jquery/1.2.6/jquery.min.js”></script> 
24、关闭jquery动画效果 
 
 
$(document).ready(function(){ jQuery.fx.off=true;}); 
25、使用自己的jquery标识 
 
 
$(document).ready(function(){var $jq = jQuery.noConflict(); $jq(‘#id’).show();});