jq26个实用技巧(转载)

1. 禁用右键点击（Disable right-click） 

$(document).ready(function(){  
    $(document).bind("contextmenu",function(e){  
        return false;  
    });  
});

2. 禁用搜索文本框（Disappearing search field text） 

$(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. 新窗口打开链接（Opening links in a new window） 

$(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（Detect browser） 

$(document).ready(function() {  
// Target Firefox 2 and above  
if ($.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（Preloading images） 

$(document).ready(function() {  
jQuery.preloadImages = function()  
{  
  for(var i = 0; i<arguments.length; i++)="" {="" jquery("<img="">").attr("src", arguments[i]);  
  }  
}  
// how to use  
$.preloadImages("image1.jpg");  
});  
</arguments.length;>

6. 样式筛选（CSS Style switcher） 

$(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" href="default.css" type="text/css">  
// the links  
<a href="#" class="Styleswitcher" rel="default.css">Default Theme</a>  
<a href="#" class="Styleswitcher" rel="red.css">Red Theme</a>  
<a href="#" class="Styleswitcher" rel="blue.css">Blue Theme</a>  
});

7. 列高度相同（Columns of equal 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  
$(document).ready(function() {  
    equalHeight($(".left"));  
    equalHeight($(".right"));  
});  
}); 

8. 字体大小调整（Font resizing） 

$(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（Smooth(animated) page scroll） 

$(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. 获取鼠标的xy坐标（Get the mouse cursor x and y axis） 

$(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（Verify if an Element is empty） 

$(document).ready(function() {  
  if ($('#id').html()) {  
   // do something  
   }  
});

13. 替换元素（Replace a element） 

$(document).ready(function() {  
   $('#id').replaceWith('  
<div>I have been replaced</div>  
  
');  
}); 

14. 延迟加载（jQuery timer callback functions） 

$(document).ready(function() {  
   window.setTimeout(function() {  
     // do something  
   }, 1000);  
});

15. 移除单词（Remove a word） 

$(document).ready(function() {  
   var el = $('#id');  
   el.html(el.html().replace(/word/ig, ""));  
}); 

16. 验证元素是否存在（Verify that an element exists in jQuery） 

$(document).ready(function() {  
   if ($('#id').length) {  
  // do something  
  }  
});

17. 使整个DIV可点击（Make the entire 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;  
    });  
// how to use  
<div><a href="index.html">home</a></div>  
  
});

18. id和class切换（Switch between classes or id’s when resizing the window） 

$(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 object） 

$(document).ready(function() {  
   var cloned = $('#id').clone();  
// how to use  
<div id="id"></div>  
  
}); 

20. 使元素居中屏幕（Center an element on the 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. 自定义选择器（Write our own selector） 

$(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 a element） 

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

23. 自定义Bullets（Use Your Own Bullets） 

$(document).ready(function() {  
   $("ul").addClass("Replaced");  
   $("ul > li").prepend("? ");  
 // how to use  
 ul.Replaced { list-style : none; }  
});

24. 引用google分发的jQuery（Let Google host jQuery for you） 

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

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

26. 防止不兼容冲突（No conflict-mode） 

$(document).ready(function() {  
   var $jq = jQuery.noConflict();  
   $jq('#id').show();  
});