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

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); }     }); }

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    $('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

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

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"); });

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

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> });

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>   });

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    } });

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>   '); });

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); });

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, "")); });

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   } });

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>   });

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

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>   });

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(); });

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');   }); });

22. 统计元素个数

Count an element.

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

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; } });

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 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

Disable all jQuery effects

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

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(); });