26个 jQuery 使用小技巧

/*
1. Disable right-click(禁用右键)
Disable right-click contextual menu.
*/
$(document).ready(function(){
$(document).bind(”contextmenu”,function(e){
return false;
});
});

/*
* 2. Disappearing search field text(隐藏搜索文本框文字)
Hide when clicked in the search field, the value.(example can be found below in the comment fields)
*/
$(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. Opening links in a new window(在新窗口中打开链接)
XHTML 1.0 Strict doesn't allow this attribute in the code, so use this to keep the code valid.
*/
$(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";
});
});

/*
4. Detect browser(检测浏览器)
Change/add something for a certain browser.
Notice: As of jQuery 1.4, the $.browser variable is replaced by $.support.
*/

$(document).ready(function() {
// Target Firefox 2 and above
if ($.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. Preloading images(预加载图片)
This piece of code will prevent the loading of all images, which can be useful if you have a site with lots of images.
这段代码有问题
*/
$(document).ready(function() {
jQuery.preloadImages = function(){
for(var i = 0; i”).attr(”src”, arguments[i]);
}
}
// how to use
$.preloadImages(”image1.jpg”);
});

/*
6. css Styleswitcher(页面样式切换)
Switch between different styles?
*/
$(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'));
});
});

/*
7. Columns of equal height(列高度相同)
If you are using two css columns, use this to make them exactly the same height.
*/
$(document).ready(function() {
function equalHeight(group) {
tallest = 0;
group.each(function() {
thisHeight = $(this).height();
if(thisHeight > tallest) {
tallest = thisHeight;
}
});
group.height(tallest);
}
// how to use
equalHeight($(".left"));
equalHeight($(".right"));
});

/*
8. Font resizing(动态控制页面字体大小)
Want to let the users change there font size?
*/
$(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. Smooth(animated) page scroll( 返回页面顶部功能)
For a smooth(animated) ride back to the top(or any location).
*/
$(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;
}
}
});
});

/*
11. Get the mouse cursor x and y axis(获得鼠标指针的坐标值)
Want to know where your mouse cursor is?
*/
$(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);
});
});

/*
12. Verify if an Element is empty(验证元素是否为空)
This will allow you to check if an element is empty.
*/
$(document).ready(function() {
if ($('#id').html()) {
// do something
}
});

/*
13. Replace a element(替换元素)
Want to replace a div, or something else?
*/
$(document).ready(function() {
$('#id').replaceWith('

I have been replaced');
});

/*
14. jQuery timer callback functions(jQuery延时加载功能)
Want to delay something?
*/
$(document).ready(function() {
window.setTimeout(function() {
// do something
}, 1000);
});

/*
15. Remove a word(移除单词功能)
Want to remove a certain word(s)?
*/
$(document).ready(function() {
var el = $('#id');
el.html(el.html().replace(/word/ig, ""));
});

/*
16. Verify that an element exists in jQuery(验证元素是否存在于 jQuery 对象集合中)
Simply test with the .length property if the element exists.
*/
$(document).ready(function() {
if ($('#id').length) {
// do something
}
});

/*
17. Make the entire DIV clickable(使整个 Div 可点击)
Want to make the complete div clickable?
*/
$(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;
});
});

/*
18. Switch between classes or id's when resizing the window.(ID与Class之间转换)
Want to switch between a class or id, when resizing the window?
*/
$(document).ready(function() {
function checkWindowSize() {
if ( $(window).width() > 1200 ) {
$('body').addClass('large');
} else {
$('body').removeClass('large');
}
}
$(window).resize(checkWindowSize);
});

/*
19. Clone a object(克隆对象)
Clone a div or an other element.
*/
$(document).ready(function() {
var cloned = $('#id').clone();
});
});

/*
20. Center an element on the screen(使元素居屏幕中间位置)
Center an element in the center of your screen.
*/
$(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. Write our own selector(写自己的选择器)
Write your own selectors.
*/
$(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. Count a element(统计元素个数)
Count an element.
*/
$(document).ready(function() {
$("p").size();
});

/*
23. Use Your Own Bullets(使用自己的 Bullets)
Want to use your own bullets instead of using the standard or images bullets?
*/
$(document).ready(function() {
$("ul").addClass("Replaced");
$("ul > li").prepend("‒ ");
});

/*
24. Let Google host jQuery for you(引用Google主机上的Jquery类库)
Let Google host the jQuery script for you. This can be done in 2 ways.
*/
// Example 1

/*
25. Disable jQuery animations(禁用Jquery（动画）效果)
Disable all jQuery effects
*/
$(document).ready(function() {
jQuery.fx.off = true;
});

/*
26. No conflict-mode(与其他Javascript类库冲突解决方案)
To avoid conflict other libraries on your website, you can use this jQuery Method, and assign a different variable name instead of the dollar sign.
*/
$(document).ready(function() {
var $jq = jQuery.noConflict();
$jq('#id').show();
});