jQuery使用技巧

1. 禁用右键点击（Disable right-click）

[javascript]
view plaincopyprint?

$(document).ready(function(){ $(document).bind("contextmenu",function(e){ return false; }); });

$(document).ready(function(){
$(document).bind("contextmenu",function(e){
return false;
});
});

2. 禁用搜索文本框（Disappearing search field text）

[javascript]
view plaincopyprint?

$(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); }
});
}

$(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. 新窗口打开链接（Opening links in a new window）

[javascript]
view plaincopyprint?

$(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>

$(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. 检测浏览器（Detect browser）

[javascript]
view plaincopyprint?

$(document).ready(function() {
// Target Firefox 2 and above
if ($.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
}
});

$(document).ready(function() {
// Target Firefox 2 and above
if ($.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（Preloading images）

[javascript]
view plaincopyprint?

$(document).ready(function() {
jQuery.preloadImages = function()
{
for(var i = 0; i<arguments.length; i++)="" {="" jquery("<img="">").attr("src", arguments[i]);
}
}
// how to use
$.preloadImages("image1.jpg");
});
</arguments.length;>

$(document).ready(function() {
jQuery.preloadImages = function()
{
for(var i = 0; i<arguments.length; i++)="" {="" jquery("<img="">").attr("src", arguments[i]);
}
}
// how to use
$.preloadImages("image1.jpg");
});
</arguments.length;>

6. 样式筛选（CSS Style switcher）

[javascript]
view plaincopyprint?

$(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="#" class="Styleswitcher" 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>
});

$(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="#" class="Styleswitcher" 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. 列高度相同（Columns of equal height）

[javascript]
view plaincopyprint?

$(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")); }); });

$(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. 字体大小调整（Font resizing）

[javascript]
view plaincopyprint?

$(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);
return false;
});
// 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);
return false;
});
});

$(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);
return false;
});
// 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);
return false;
});
});

9. 返回页面顶部（Smooth(animated) page scroll）

[javascript]
view plaincopyprint?

$(document).ready(function() {
$('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);
return false;
}
}
});
// how to use
// place this where you want to scroll to

<a name="top"></a>
// the link
<a href="#top">go to top</a>
});

$(document).ready(function() {
$('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);
return false;
}
}
});
// how to use
// place this where you want to scroll to
<a name="top"></a>
// the link
<a href="#top">go to top</a>
});

11. 获取鼠标的xy坐标（Get the mouse cursor x and y axis）

[javascript]
view plaincopyprint?

$(document).ready(function() {
$().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);
});
// how to use
<div id="XY"></div>

});

$(document).ready(function() {
$().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);
});
// how to use
<div id="XY"></div>

});

12. 验证元素是否为空（Verify if an Element is empty）

[javascript]
view plaincopyprint?

$(document).ready(function() { if ($('#id').html()) { // do something } });

$(document).ready(function() {
if ($('#id').html()) {
// do something
}
});

13. 替换元素（Replace a element）

[javascript]
view plaincopyprint?

$(document).ready(function() { $('#id').replaceWith(' <div>I have been replaced</div> '); });

$(document).ready(function() {
$('#id').replaceWith('
<div>I have been replaced</div>

');
});

14. 延迟加载（jQuery timer callback functions）

[javascript]
view plaincopyprint?

$(document).ready(function() { window.setTimeout(function() { // do something }, 1000); });

$(document).ready(function() {
window.setTimeout(function() {
// do something
}, 1000);
});

15. 移除单词（Remove a word）

[javascript]
view plaincopyprint?

$(document).ready(function() { var el = $('#id'); el.html(el.html().replace(/word/ig, "")); });

$(document).ready(function() {
var el = $('#id');
el.html(el.html().replace(/word/ig, ""));
});

16. 验证元素是否存在（Verify that an element exists in jQuery）

[javascript]
view plaincopyprint?

$(document).ready(function() { if ($('#id').length) { // do something } });

$(document).ready(function() {
if ($('#id').length) {
// do something
}
});

17. 使整个DIV可点击（Make the entire DIV clickable）

[javascript]
view plaincopyprint?

$(document).ready(function() {
$("div").click(function(){
//get the url from href attribute and launch the url

window.location=$(this).find("a").attr("href"); return false;
});
// how to use
<div><a href="index.html">home</a></div>

});

$(document).ready(function() {
$("div").click(function(){
//get the url from href attribute and launch the url
window.location=$(this).find("a").attr("href"); return false;
});
// how to use
<div><a href="index.html">home</a></div>

});

18. id和class切换（Switch between classes or id’s when resizing the window）

[javascript]
view plaincopyprint?

$(document).ready(function() { function checkWindowSize() { if ( $(window).width() > 1200 ) { $('body').addClass('large'); } else { $('body').removeClass('large'); } } $(window).resize(checkWindowSize); });

$(document).ready(function() {
function checkWindowSize() {
if ( $(window).width() > 1200 ) {
$('body').addClass('large');
}
else {
$('body').removeClass('large');
}
}
$(window).resize(checkWindowSize);
});

19. 克隆对象（Clone a object）

[javascript]
view plaincopyprint?

$(document).ready(function() { var cloned = $('#id').clone(); // how to use <div id="id"></div> });

$(document).ready(function() {
var cloned = $('#id').clone();
// how to use
<div id="id"></div>

});

20. 使元素居中屏幕（Center an element on the screen）

[javascript]
view plaincopyprint?

$(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");
return this;
}
$("#id").center();
});

$(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");
return this;
}
$("#id").center();
});

21. 自定义选择器（Write our own selector）

[javascript]
view plaincopyprint?

$(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');
});
});

$(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');
});
});

22. 统计元素个数（Count a element）

[javascript]
view plaincopyprint?

$(document).ready(function() { $("p").size(); });

$(document).ready(function() {
$("p").size();
});

23. 自定义Bullets（Use Your Own Bullets）

[javascript]
view plaincopyprint?

$(document).ready(function() { $("ul").addClass("Replaced"); $("ul > li").prepend("‒ "); // how to use ul.Replaced { list-style : none; } });

$(document).ready(function() {
$("ul").addClass("Replaced");
$("ul > li").prepend("‒ ");
// how to use
ul.Replaced { list-style : none; }
});

24. 引用google分发的jQuery（Let Google host jQuery for you）

[javascript]
view plaincopyprint?

//Example 1
<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>

//Example 1
<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>

25. 禁用jQuery动画（Disable jQuery animations）

[javascript]
view plaincopyprint?

$(document).ready(function() { jQuery.fx.off = true; });

$(document).ready(function() {
jQuery.fx.off = true;
});

26. 防止不兼容冲突（No conflict-mode）

[javascript]
view plaincopyprint?

$(document).ready(function() { var $jq = jQuery.noConflict(); $jq('#id').show(); });

$(document).ready(function() {
var $jq = jQuery.noConflict();
$jq('#id').show();
});