JQuery超实用代码段25则

2015-12-30 12:30  阅读 2,707 次 评论 2 条

分享一些Jquery超实用代码段。包括: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。欢迎广大博友留言补充,采纳后会在后面添加贡献者及外链。

1. 禁止右键点击

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

2. 隐藏搜索文本框文字

$(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.

$(document).ready(function() {
   //例1:每个链接都在新窗口打开
   $('a[href^="http://"]').attr("target", "_blank");
   //例2:只有带external属性的链接在新窗口打开
   $('a[@rel$='external']').click(function(){
      this.target = "_blank";
   });
});
// 使用案例
<a href="http://www.humicai.cn" 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

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

$(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

$(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。

$(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

$(document).ready(function() {
  // 重置字体
  var originalFontSize = $('html').css('font-size');
    $(".resetFont").click(function(){
    $('html').css('font-size', originalFontSize);
  });
  // 增大字体
  $(".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;
  });
  // 减小字体
  $(".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).

$(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

$(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.

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

13. 替换元素

Want to replace a div, or something else?

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

14. jQuery延时加载功能

Want to delay something?

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

15. 移除单词功能

Want to remove a certain word(s)?

$(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.

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

17. 使整个div可点击

$(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

$(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.

$(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.

$(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

$(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

$(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?

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

24. 禁用Jquery(动画)效果

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

25. 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.

$(document).ready(function() {
   var $jq = jQuery.noConflict();
   $jq('#id').show();
});
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  1. 百家网络博客
    百家网络博客 【初级粉丝】 @回复

    有些功能是实现了,但写得不够好