jQuery 常用代码集锦(必看篇)

前端技术 2023/09/09 JavaScript

1. 选择或者不选页面上全部复选框

var tog = false; // or true if they are checked on load
$(\'a\').click(function() {
 $(\"input[type=checkbox]\").attr(\"checked\",!tog);
 tog = !tog;
});

2. 取得鼠标的X和Y坐标

$(document).mousemove(function(e){
$(document).ready(function() {
$().mousemove(function(e){
$(\'#XY\').html(\"Gbin1 X Axis : \" + e.pageX + \" | Gbin1 Y Axis \" + e.pageY);
});
});

3. 判断一个图片是否加载完全

$(\'#theGBin1Image\').attr(\'src\', \'image.jpg\').load(function() {
alert(\'This Image Has Been Loaded\');
});

4. 判断cookie是否激活或者关闭

var dt = new Date();
dt.setSeconds(dt.getSeconds() + 60);
document.cookie = \"cookietest=1; expires=\" + dt.toGMTString();
var cookiesEnabled = document.cookie.indexOf(\"cookietest=\") != -1;
if(!cookiesEnabled)
{
 //cookies have not been enabled
}

5. 强制过期cookie

var date = new Date();
date.setTime(date.getTime() + (x * 60 * 1000));
$.cookie(\'example\', \'foo\', { expires: date });

6. 在表单中禁用“回车键”,表单的操作中需要防止用户意外的提交表单

$(\"#form\").keypress(function(e) {
 if (e.which == 13) {
 return false;
 }
});

7. 清除所有的表单数据

function clearForm(form) {
 // iterate over all of the inputs for the form
 // element that was passed in
 $(\':input\', form).each(function() {
 var type = this.type;
 var tag = this.tagName.toLowerCase(); // normalize case
 // it\'s ok to reset the value attr of text inputs,
 // password inputs, and textareas
 if (type == \'text\' || type == \'password\' || tag == \'textarea\')
  this.value = \"\";
 // checkboxes and radios need to have their checked state cleared
 // but should *not* have their \'value\' changed
 else if (type == \'checkbox\' || type == \'radio\')
  this.checked = false;
 // select elements need to have their \'selectedIndex\' property set to -1
 // (this works for both single and multiple select elements)
 else if (tag == \'select\')
  this.selectedIndex = -1;
 });
};

8.禁止多次递交表单

$(document).ready(function() {
 $(\'form\').submit(function() {
 if(typeof jQuery.data(this, \"disabledOnSubmit\") == \'undefined\') {
  jQuery.data(this, \"disabledOnSubmit\", { submited: true });
  $(\'input[type=submit], input[type=button]\', this).each(function() {
  $(this).attr(\"disabled\", \"disabled\");
  });
  return true;
 }
 else
 {
  return false;
 }
 });
});

9. 自动将数据导入selectbox中

$(function(){
 $(\"select#ctlJob\").change(function(){
 $.getJSON(\"/select.php\",{id: $(this).val(), ajax: \'true\'}, function(j){
  var options = \'\';
  for (var i = 0; i < j.length; i++) {
  options += \'<option value=\"\' + j[i].optionValue + \'\">\' + j[i].optionDisplay + \'</option>\';
  }
  $(\"select#ctlPerson\").html(options);
 })
 })
})

10. 创建一个嵌套的过滤器

.filter(\":not(:has(.selected))\") //去掉所有不包含class为.selected的元素

11. 使用has()来判断一个元素是否包含特定的class或者元素

//jQuery 1.4.* includes support for the has method. This method will find 
//if a an element contains a certain other element class or whatever it is 
//you are looking for and do anything you want to them. 
$(\"input\").has(\".email\").addClass(\"email_icon\");

12. 使用jQuery切换样式

//Look for the media-type you wish to switch then set the href to your new style sheet 
$(\'link[media=\'screen\']\').attr(\'href\', \'Alternative.css\'); 

13. 如何正确使用ToggleClass

//Toggle class allows you to add or remove a class 
//from an element depending on the presence of that 
//class. Where some developers would use: 
a.hasClass(\'blueButton\') ? a.removeClass(\'blueButton\') : a.addClass(\'blueButton\'); 
//toggleClass allows you to easily do this using 
a.toggleClass(\'blueButton\');

14. 使用jQuery来替换一个元素

$(\'#thatdiv\').replaceWith(\'fnuh\');

15.绑定一个函数到一个事件

$(\'#foo\').bind(\'click\', function() { 
 alert(\'User clicked on \"foo.\"\'); 
}); 

16. 使用jQuery预加载图片

jQuery.preloadImages = function() { for(var i = 0; i\').attr(\'src\', arguments[i]); } }; 
// Usage $.preloadImages(\'image1.gif\', \'/path/to/image2.png\', \'some/image3.jpg\'); 

17. 设置任何匹配一个选择器的事件处理程序

$(\'button.someClass\').live(\'click\', someFunction);
 //Note that in jQuery 1.4.2, the delegate and undelegate options have been
 //introduced to replace live as they offer better support for context
 //For example, in terms of a table where before you would use..
 // .live()
 $(\"table\").each(function(){
 $(\"td\", this).live(\"hover\", function(){
 $(this).toggleClass(\"hover\");
 });
 });
 //Now use..
 $(\"table\").delegate(\"td\", \"hover\", function(){
 $(this).toggleClass(\"hover\");
});

18. 自动的滚动到页面特定区域

jQuery.fn.autoscroll = function(selector) {
 $(\'html,body\').animate(
 {scrollTop: $(selector).offset().top},

 );
}
//Then to scroll to the class/area you wish to get to like this:
$(\'.area_name\').autoscroll();

19.检测各种浏览器

Detect Safari (if( $.browser.safari)),
Detect IE6 and over (if ($.browser.msie && $.browser.version > 6 )),
Detect IE6 and below (if ($.browser.msie && $.browser.version <= 6 )),
Detect FireFox 2 and above (if ($.browser.mozilla && $.browser.version >= \'1.8\' )

20.限制textarea的字符数量

jQuery.fn.maxLength = function(max){
 this.each(function(){
 var type = this.tagName.toLowerCase();
 var inputType = this.type? this.type.toLowerCase() : null;
 if(type == \"input\" && inputType == \"text\" || inputType == \"password\"){
  //Apply the standard maxLength
  this.maxLength = max;
 }
 else if(type == \"textarea\"){
  this.onkeypress = function(e){
  var ob = e || event;
  var keyCode = ob.keyCode;
  var hasSelection = document.selection? document.selection.createRange().text.length > 0 : this.selectionStart != this.selectionEnd;
  return !(this.value.length >= max && (keyCode > 50 || keyCode == 32 || keyCode == 0 || keyCode == 13) && !ob.ctrlKey && !ob.altKey && !hasSelection);
  };
  this.onkeyup = function(){
  if(this.value.length > max){
   this.value = this.value.substring(0,max);
  }
  };
 }
 });
};
//Usage:
$(\'#gbin1textarea\').maxLength(500);

21.使用jQuery克隆元素

var cloned = $(\'#gbin1div\').clone();

22. 元素屏幕居中

jQuery.fn.center = function () {
 this.css(\'position\',\'absolute\');
 this.css(\'top\', ( $(window).height() - this.height() ) / +$(window).scrollTop() + \'px\');
 this.css(\'left\', ( $(window).width() - this.width() ) / 2+$(window).scrollLeft() + \'px\');return this;
}
//Use the above function as: $(\'#gbin1div\').center();

23 .简单的tab标签切换

jQuery(\'#meeting_tabs ul li\').click(function(){
  jQuery(this).addClass(\'tabulous_active\').siblings().removeClass(\'tabulous_active\');
  jQuery(\'#tabs_container>.pane:eq(\'+jQuery(this).index()+\')\').show().siblings().hide(); 
 })

<div id=\"meeting_tabs\">
    <ul>
      <li class=\"tabulous_active\"><a href=\"#\" title=\"\">进行中</a></li>
      <li><a href=\"#\" title=\"\">未开始</a></li>
      <li><a href=\"#\" title=\"\">已结束</a></li>
      <li><a href=\"#\" title=\"\">全部</a></li>
     </ul>
 <div id=\"tabs_container\">
   <div class=\"pane\"  >1</div>
   <div class=\"pane\"  >2</div>
   <div class=\"pane\"  >3</div>
   <div class=\"pane\"  >4</div>
 </div>
</div>

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