26个Jquery使用小技巧
下面列出了一些Jquery使用技巧。比如有禁止右键点击、隐藏搜索文本框文字、在新窗口中打开链接、检测浏览器、预加载图片、页面样式切换、所有列等高、动态控制页面字体大小、获得鼠标指针的X值Y值、验证元素是否为空、替换元素、延迟加载、验证元素是否存在于Jquery集合中、使DIV可点击、克隆对象、使元素居中、计算元素个数、使用Google主机上的Jquery类库、禁用Jquery效果、解决Jquery类库与其他Javascript类库冲突问题。 1. 禁止右键点击
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$(document).ready(function(){
$(document).bind("contextmenu",function(e){
return false;
});
});
2. 隐藏搜索文本框文字
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$(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( $.trim(input.val()) == '' ){ input.val(originalvalue); }
});
}
3. 在新窗口中打开链接
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$(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.cdtarena.com" rel=external>open link</A>
4. 检测浏览器
注: 在版本jQuery 1.4中，$.support 替换掉了$.browser 变量
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$(document).ready(function(){
// Target Firefox 2 and above
if ($.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 && $.browser.version > 6){
// do something
}
});
5. 预加载图片
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$(document).ready(function(){
jQuery.preloadImages = function()
{
for(var i = 0; i<ARGUMENTS.LENGTH; jQuery(?<img { i++)>").attr("src", arguments[i]);
}
}
// how to use
$.preloadImages("image1.jpg");
});
6. 页面样式切换
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$(document).ready(function() {
$("a.Styleswitcher").click(function() {
//swicth the LINK REL attribute with the value in A REL attribute
$('link[rel=stylesheet]').attr('href' , $(this).attr('rel'));
});
// how to use
// place this in your header
<LINK rel=stylesheet type=text/css href="default.css">
// the links
<A class=Styleswitcher href="#" rel=default.css>Default Theme</A>
<A class=Styleswitcher href="#" rel=red.css>Red Theme</A>
<A class=Styleswitcher href="#" rel=blue.css>Blue Theme</A>
});
7. 列高度相同
如果使用了两个CSS列，使用此种方式可以是两列的高度相同。
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$(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($(".right"));
});
});
8. 动态控制页面字体大小
用户可以改变页面字体大小
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$(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;
$('html').css('font-size', newFontSize);
return false;
});
});
9. 返回页面顶部功能
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$(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;
$('html,body')
.animate({scrollTop: targetOffset}, 900);
return false;
}
}
});
// how to use
// place this where you want to scroll to
<A name=top></A>
// the link
<A href="#top">go to top</A>
});
11. 获得鼠标指针ＸＹ值
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$(document).ready(function() {
$().mousemove(function(e){
//display the x and y axis values inside the div with the id XY
$('#XY')("X Axis : " + e.pageX + " | Y Axis " + e.pageY);
}); // how to use
<DIV id=XY></DIV>
});
12. 验证元素是否为空
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$(document).ready(function() {
if ($('#id')()) {
// do something
}
});
13. 替换元素
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$(document).ready(function() {
$('#id').replaceWith('
<DIV>I have been replaced</DIV>
');
});
14. jQuery延时加载功能
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$(document).ready(function() {
window.setTimeout(function() {
// do something
}, 1000);
});
15. 移除单词功能
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$(document).ready(function() {
var el = $('#id');
el(el().replace(/word/ig, ""));
});
16. 验证元素是否存在于jquery对象集合中
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$(document).ready(function() {
if ($('#id').length) {
// do something
}
});
17. 使整个DIV可点击
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$(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">home</A></DIV>
});
18. 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');
}
}
$(window).resize(checkWindowSize);
});
19. 克隆对象
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$(document).ready(function() {
var cloned = $('#id').clone();
// how to use
<DIV id=id></DIV>
});
20. 使元素居屏幕中间位置
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$(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;
}
$("#id").center();
});
21. 写自己的选择器
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$(document).ready(function() {
$.extend($.expr[':'], {
moreThen1000px: function(a) {
return $(a).width() > 1000;
}
});
$('.box:moreThen1000px').click(function() {
// creating a simple js alert box
alert('The element that you have clicked is over 1000 pixels wide');
});
});
22. 统计元素个数
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$(document).ready(function() {
$("p").size();
});
23. 使用自己的 Bullets
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$(document).ready(function() {
$("ul").addClass("Replaced");
$("ul > li").prepend("‒ ");
// how to use
ul.Replaced { list-style : none; }
});
24. 引用Google主机上的Jquery类库
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//Example 1
<SCRIPT src="http://www.google.com/jsapi"></SCRIPT>
<SCRIPT type=text/javascript> google.load("jquery", "1.2.6");
google.setOnLoadCallback(function() {
// do something });
</SCRIPT><SCRIPT type=text/javascript src="http://ajax.googleapis.com/ajax/libs/jquery/1.2.6/jquery.min.js"></SCRIPT>
// Example 2:(the best and fastest way)
<SCRIPT type=text/javascript src="http://ajax.googleapis.com/ajax/libs/jquery/1.2.6/jquery.min.js"></SCRIPT>
25. 禁用Jquery（动画）效果
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$(document).ready(function() {
jQuery.fx.off = true;
});
26. 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();
});
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