12个Jquery使用技巧

1. 禁止右键点击

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$(document).ready(function(){

$(document).bind("contextmenu",function(e){

return false;

});

});

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$(document).ready(function(){

$(document).bind("contextmenu",function(e){

return false;

});

});

2. 预加载图片

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$(document).ready(function(){

jQuery.preloadImages = function()

{

for(var i
= 0; i<ARGUMENTS.LENGTH; jQuery(?<img { i++)>").attr("src",
arguments[i]);

}

}

// how to use

$.preloadImages("image1.jpg");

});

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$(document).ready(function(){

jQuery.preloadImages = function()

{

for(var i = 0; i<ARGUMENTS.LENGTH; jQuery(?<img { i++)>").attr("src", arguments[i]);

}

}

// how to use

$.preloadImages("image1.jpg");

});

3. 页面样式切换

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$(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 type=text/css href="default.css">

// the links

<A class=Styleswitcher
href="#" rel=default.css>Default
Theme</A>

<A class=Styleswitcher
href="#" rel=red.css>Red Theme</A>

<A class=Styleswitcher
href="#" rel=blue.css>Blue Theme</A>

});

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$(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 type=text/css href="default.css">

// the links

<A class=Styleswitcher href="#" rel=default.css>Default Theme</A>

<A class=Styleswitcher href="#" rel=red.css>Red Theme</A>

<A class=Styleswitcher href="#" rel=blue.css>Blue Theme</A>

});

4. 列高度相同

如果使用了两个CSS列，使用此种方式可以是两列的高度相同。

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$(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"));

});

});

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$(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"));

});

});

5. 动态控制页面字体大小

用户可以改变页面字体大小

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$(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;

});

});

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$(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;

});

});

6. 返回页面顶部功能

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$(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>

});

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$(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>

});

7. jQuery延时加载功能

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$(document).ready(function()
{

window.setTimeout(function()
{

// do something

}, 1000);

});

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$(document).ready(function() {

window.setTimeout(function() {

// do something

}, 1000);

});

8. ID与Class之间转换.

当改变Window大小时，在ID与Class之间切换

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$(document).ready(function()
{

function checkWindowSize()
{

if (
$(window).width() > 1200 ) {

$('body').addClass('large');

}

else {

$('body').removeClass('large');

}

}

$(window).resize(checkWindowSize);

});

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$(document).ready(function() {

function checkWindowSize() {

if ( $(window).width() > 1200 ) {

$('body').addClass('large');

}

else {

$('body').removeClass('large');

}

}

$(window).resize(checkWindowSize);

});

9. 使元素居屏幕中间位置

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$(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();

});

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$(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();

});

10. 引用Google主机上的Jquery类库

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//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 type=text/javascript src="http://ajax.googleapis.com/ajax/libs/jquery/1.2.6/jquery.min.js"></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>

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//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 type=text/javascript src="http://ajax.googleapis.com/ajax/libs/jquery/1.2.6/jquery.min.js"></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>

11. 禁用Jquery（动画）效果

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$(document).ready(function()
{

jQuery.fx.off = true;

});

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$(document).ready(function() {

jQuery.fx.off = true;

});

12. 与其他Javascript类库冲突解决方案

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$(document).ready(function()
{

var $jq
= jQuery.noConflict();

$jq('#id').show();

});