26 个 jQuery使用技巧

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();
});