26个Jquery使用小技巧(jQuery tips, tricks & solutions)

 

前段时间发布了Jquery类库1.4版本，使用者也越来越多，为了方便大家对Jquery的使用，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。

具体如下：

1. 禁止右键点击view plaincopy to clipboardprint?
       $(document).ready(function(){  
           $(document).bind("contextmenu",function(e){  
               return false;  
           });  
       }); 
2. 隐藏搜索文本框文字view plaincopy to clipboardprint?
      $(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view plaincopy to clipboardprint?
      $(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view plaincopy to clipboardprint?
       $(document).ready(function() {  
          jQuery.preloadImages = function()  
         {  
            for(var i = 0; i").attr("src", arguments[i]); 
         } 
       }; 
       // how to use 
       $.preloadImages("image1.jpg");  
       }); 
6. 页面样式切换view plaincopy to clipboardprint?
      $(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 href="default.css" type=text/css rel=stylesheet>  
      // 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view plaincopy to clipboardprint?
      $(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view plaincopy to clipboardprint?
       $(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view plaincopy to clipboardprint?
       $(document).ready(function() {  
         if ($('#id').html()) {  
          // do something  
          }  
       }); 
13. 替换元素view plaincopy to clipboardprint?
       $(document).ready(function() {  
          $('#id').replaceWith(' 
       <DIV>I have been replaced</DIV> 
       
       ');  
       }); 
14. jQuery延时加载功能view plaincopy to clipboardprint?
       $(document).ready(function() {  
          window.setTimeout(function() {  
            // do something  
          }, 1000);  
       }); 
15. 移除单词功能view plaincopy to clipboardprint?
       $(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view plaincopy to clipboardprint?
       $(document).ready(function() {  
          if ($('#id').length) {  
         // do something  
         }  
       }); 
17. 使整个ＤＩＶ可点击view plaincopy to clipboardprint?
       $(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view plaincopy to clipboardprint?
       $(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view plaincopy to clipboardprint?
       $(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view plaincopy to clipboardprint?
      $(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view plaincopy to clipboardprint?
       $(document).ready(function() {  
          $("p").size();  
       }); 
23. 使用自己的 Bulletsview plaincopy to clipboardprint?
       $(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 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 src="http://ajax.googleapis.com/ajax/libs/jquery/1.2.6/jquery.min.js" type=text/javascript></SCRIPT> 
 25. 禁用Jquery（动画）效果view plaincopy to clipboardprint?
       $(document).ready(function() {  
           jQuery.fx.off = true;  
       }); 
26. 与其他Javascript类库冲突解决方案view plaincopy to clipboardprint?
       $(document).ready(function() {  
          var $jq = jQuery.noConflict();  
          $jq('#id').show();  
       });