Jquery使用小技巧汇总

前端技术 2023/09/08 JavaScript

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

$(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)

$(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() {
  //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

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

$(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?

$(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
Want to make the complete 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
Write your own selectors.

$(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.

$(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. 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.

[code]//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>[/code]

25. 禁用Jquery（动画）效果
Disable all jQuery effects

$(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.

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

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