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
(){
$(document).bind(
"contextmenu"
,
function
(e){
return
false
;
});
});
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2. 隐藏搜索文本框文字
Hide when clicked in the search field, the value.(example can be found below in the comment fields)
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$(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
( $.trim(input.val()) ==
''
){ input.val(originalvalue); }
});
}
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3. 在新窗口中打开链接
XHTML 1.0 Strict doesn’t allow this attribute in the code, so use this to keep the code valid.
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$(document).ready(
function
() {
//Example 1: Every link will open in a new window
//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
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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 && $.browser.version > 6){
// do something
}
});
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5. 预加载图片
This piece of code will prevent the loading of all images, which can be useful if you have a site with lots of images.
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$(document).ready(
function
() {
jQuery.preloadImages =
function
()
{
for
(
var
i = 0; i<ARGUMENTS.LENGTH; jQuery(?<img { i++)>
").attr("
src
", arguments[i]);
}
}
// how to use
$.preloadImages("
image1.jpg");
});
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6. 页面样式切换
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$(document).ready(
function
() {
$(
"a.Styleswitcher"
).click(
function
() {
//swicth the LINK REL attribute with the value in A REL attribute
$(
'link[rel=stylesheet]'
).attr(
'href'
, $(
this
).attr(
'rel'
));
});
// how to use
// place this in your header
<LINK rel=stylesheet type=text/css href=
"default.css"
>
// the links
<A class="Styleswitcher" href=
"#"
rel=
default
.css>Default Theme</A>
<A class="Styleswitcher" href=
"#"
rel=red.css>Red Theme</A>
<A class="Styleswitcher" href=
"#"
rel=blue.css>Blue Theme</A>
});
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7. 列高度相同
如果使用了两个CSS列，使用此种方式可以是两列的高度相同。
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$(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($(
".right"
));
});
});
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8. 动态控制页面字体大小
用户可以改变页面字体大小
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$(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;
$(
'html'
).css(
'font-size'
, newFontSize);
return
false
;
});
});
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9. 返回页面顶部功能
For a smooth(animated) ride back to the top(or any location).
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$(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;
$(
'html,body'
)
.animate({scrollTop: targetOffset}, 900);
return
false
;
}
}
});
// how to use
// place this where you want to scroll to
<A name=top></A>
// the link
<A href=
"#top"
>go to top</A>
});
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11. 获得鼠标指针ＸＹ值
Want to know where your mouse cursor is?
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$(document).ready(
function
() {
$().mousemove(
function
(e){
//display the x and y axis values inside the div with the id XY
$(
'#XY'
).html(
"X Axis : "
+ e.pageX +
" | Y Axis "
+ e.pageY);
});
// how to use
<DIV id=XY></DIV>
});
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12. 验证元素是否为空
This will allow you to check if an element is empty.
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$(document).ready(
function
() {
if
($(
'#id'
).html()) {
// do something
}
});
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13. 替换元素
Want to replace a div, or something else?
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$(document).ready(
function
() {
$(
'#id'
).replaceWith(
'
<DIV>I have been replaced</DIV>
'
);
});
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14. jQuery延时加载功能
Want to delay something?
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$(document).ready(
function
() {
window.setTimeout(
function
() {
// do something
}, 1000);
});
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15. 移除单词功能
Want to remove a certain word(s)?
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$(document).ready(
function
() {
var
el = $(
'#id'
);
el.html(el.html().replace(/word/ig,
""
));
});
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16. 验证元素是否存在于jquery对象集合中
Simply test with the .length property if the element exists.
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$(document).ready(
function
() {
if
($(
'#id'
).length) {
// do something
}
});
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17. 使整个DIV可点击
Want to make the complete div clickable?
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$(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.html"
>home</A></DIV>
});
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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'
);
}
}
$(window).resize(checkWindowSize);
});
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19. 克隆对象
Clone a div or an other element.
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$(document).ready(
function
() {
var
cloned = $(
'#id'
).clone();
// how to use
<DIV id=id></DIV>
});
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20. 使元素居屏幕中间位置
Center an element in the center of your screen.
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$(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
;
}
$(
"#id"
).center();
});
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21. 写自己的选择器
Write your own selectors.
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$(document).ready(
function
() {
$.extend($.expr[
':'
], {
moreThen1000px:
function
(a) {
return
$(a).width() > 1000;
}
});
$(
'.box:moreThen1000px'
).click(
function
() {
// creating a simple js alert box
alert(
'The element that you have clicked is over 1000 pixels wide'
);
});
});
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22. 统计元素个数
Count an element.
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$(document).ready(
function
() {
$(
"p"
).size();
});
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23. 使用自己的 Bullets
Want to use your own bullets instead of using the standard or images bullets?
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$(document).ready(
function
() {
$(
"ul"
).addClass(
"Replaced"
);
$(
"ul > li"
).prepend(
"‒ "
);
// how to use
ul.Replaced { list-style : none; }
});
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24. 引用Google主机上的Jquery类库
Let Google host the jQuery script for you. This can be done in 2 ways.
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//Example 1
<SCRIPT type=text/javascript>
google.load(
"jquery"
,
"1.2.6"
);
google.setOnLoadCallback(
function
() {
// do something
});
</SCRIPT><SCRIPT type=text/javascript src=
"http://ajax.googleapis.com/ajax/libs/jquery/1.2.6/jquery.min.js"
></SCRIPT>
// Example 2:(the best and fastest way)
<SCRIPT type=text/javascript src=
"http://ajax.googleapis.com/ajax/libs/jquery/1.2.6/jquery.min.js"
></SCRIPT>
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25. 禁用Jquery（动画）效果
Disable all jQuery effects
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$(document).ready(
function
() {
jQuery.fx.off =
true
;
});
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26. 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.
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$(document).ready(
function
() {
var
$jq = jQuery.noConflict();
$jq(
'#id'
).show();
});
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