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jQuery代码开发技巧都有哪些

发表于:2024-10-18 作者:千家信息网编辑
千家信息网最后更新 2024年10月18日,本篇文章给大家分享的是有关jQuery代码开发技巧都有哪些,小编觉得挺实用的,因此分享给大家学习,希望大家阅读完这篇文章后可以有所收获,话不多说,跟着小编一起来看看吧。1. 创建一个嵌套的过滤器.fi
千家信息网最后更新 2024年10月18日jQuery代码开发技巧都有哪些

本篇文章给大家分享的是有关jQuery代码开发技巧都有哪些,小编觉得挺实用的,因此分享给大家学习,希望大家阅读完这篇文章后可以有所收获,话不多说,跟着小编一起来看看吧。

1. 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

2. 重用你的元素查询

var allItems = $("div.item"); var keepList = $("div#container1 div.item"); 
class names: $(formToLookAt + " input:checked").each(function() { keepListkeepList = keepList.filter("." + $(this).attr("name")); });

3. 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");

4. 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');

5. 限制选择的区域

//Where possible, pre-fix your class names with a tag name //so that jQuery doesn't have to spend more time searching //for the element you're after. Also remember that anything //you can do to be more specific about where the element is //on your page will cut down on execution/search times var in_stock = $('#shopping_cart_items input.is_in_stock');
  • Item X
  • Item Y
  • Item Z


6. 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');

7. 设置IE指定的功能

if ($.browser.msie) { // Internet Explorer is a sadist. }

8. 使用jQuery来替换一个元素

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

9. 验证一个元素是否为空

if ($('#keks').html()) { //Nothing found ;}

10. 在无序的set中查找一个元素的索引

$("ul > li").click(function () { var index = $(this).prevAll().length; });

11. 绑定一个函数到一个事件

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

12. 添加HTML到一个元素

$('#lal').append('sometext');

13. 创建元素时使用对象来定义属性

var e = $("", { href: "#", class: "a-class another-class", title: "..." });

14. 使用过滤器过滤多属性

//This precision-based approached can be useful when you use //lots of similar input elements which have different types var elements = $('#someid input[type=sometype][value=somevalue]').get();

15. 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');

16. 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");});


17. 找到被选择到的选项(option)元素

$('#someElement').find('option:selected');

18. 隐藏包含特定值的元素

$("p.value:contains('thetextvalue')").hide();

19. 自动的滚动到页面特定区域


jQuery.fn.autoscroll = function(selector) {$('html,body').animate({scrollTop: $(selector).offset().top},500);}//Then to scroll to the class/area you wish to get to like this:$('.area_name').autoscroll();

20. 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' ))

21. 替换字符串中的单词

var el = $('#id');el.html(el.html().replace(/word/ig, ''));

22. 关闭右键的菜单

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

23. 定义一个定制的选择器


$.expr[':'].mycustomselector = function(element, index, meta, stack){// element- is a DOM element// index - the current loop index in stack// meta - meta data about your selector// stack - stack of all elements to loop// Return true to include current element// Return false to explude current element};// Custom Selector usage:$('.someClasses:test').doSomething();


24. 判断一个元素是否存在

if ($('#someDiv').length) {//hooray!!! it exists...}

25. 使用jQuery判断鼠标的左右键点击


$("#someelement").live('click', function(e) {if( (!$.browser.msie && e.button == 0) || ($.browser.msie && e.button == 1) ) {alert("Left Mouse Button Clicked");}else if(e.button == 2)alert("Right Mouse Button Clicked");});
 
26. 显示或者删除输入框的缺省值//This snippet will show you how to keep a default value//in a text input field for when a user hasn't entered in//a value to replace itswap_val = [];$(".swap").each(function(i){swap_val[i] = $(this).val();$(this).focusin(function(){if ($(this).val() == swap_val[i]) {$(this).val("");}}).focusout(function(){if ($.trim($(this).val()) == "") {$(this).val(swap_val[i]);}});});  27. 指定时间后自动隐藏或者关闭元素(1.4支持)//Here's how we used to do it in 1.3.2 using setTimeoutsetTimeout(function() {$('.mydiv').hide('blind', {}, 500)}, 5000);//And here's how you can do it with 1.4 using the delay() feature (this is a lot like sleep)$(".mydiv").delay(5000).hide('blind', {}, 500); 28. 动态创建元素到DOMvar newgbin1Div = $('');newgbin1Div.attr('id','gbin1.com').appendTo('body'); 29. 限制textarea的字符数量jQuery.fn.maxLength = function(max){this.each(function(){var type = this.tagName.toLowerCase();var inputType = this.type? this.type.toLowerCase() : null;if(type == "input" && inputType == "text" || inputType == "password"){//Apply the standard maxLengththis.maxLength = max;}else if(type == "textarea"){this.onkeypress = function(e){var ob = e || event;var keyCode = ob.keyCode;var hasSelection = document.selection? document.selection.createRange().text.length > 0 : this.selectionStart != this.selectionEnd;return !(this.value.length >= max && (keyCode > 50 || keyCode == 32 || keyCode == 0 || keyCode == 13) && !ob.ctrlKey && !ob.altKey && !hasSelection);};this.onkeyup = function(){if(this.value.length > max){this.value = this.value.substring(0,max);}};}});};//Usage:$('#gbin1textarea').maxLength(500); 30. 为函数创建一个基本测试用例//Separate tests into modules.module("Module B");test("some other gbin1.com test", function() {//Specify how many assertions are expected to run within a test.expect(2);//A comparison assertion, equivalent to JUnit's assertEquals.equals( true, false, "failing test" );equals( true, true, "passing test" );}); 31. 使用jQuery克隆元素var cloned = $('#gbin1div').clone(); 32. 测试一个元素在jQuery中是否可见if($(element).is(':visible') == 'true') { //The element is Visible } 33. 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: $('#gbin1div').center(); 34. 使用特定名字的元素对应的值生成一个数组var arrInputValues = new Array();$("input[name='table[]']").each(function(){arrInputValues.push($(this).val());}); 35. 剔除元素中的HTML(function($) {$.fn.stripHtml = function() {var regexp = /<("[^"]*"|'[^']*'|[^'">])*>/gi;this.each(function() {$(this).html($(this).html().replace(regexp,""));});return $(this);}})(jQuery);//usage:$('p').stripHtml();36. 使用closest来得到父元素$('#searchBox').closest('div'); 37. 使用firebug来记录jQuery事件// Allows chainable logging// Usage: $('#someDiv').hide().log('div hidden').addClass('someClass');jQuery.log = jQuery.fn.log = function (msg) {if (console){console.log("%s: %o", msg, this);}return this;}; 38. 点击链接强制弹出新窗口jQuery('a.popup').live('click', function(){newwindow=window.open($(this).attr('href'),'','height=200,width=150');if (window.focus) {newwindow.focus()}return false;}); 39. 点击链接强制打开新标签页jQuery('a.newTab').live('click', function(){newwindow=window.open($(this).href);jQuery(this).target = "_blank";return false;}); 40. 使用siblings()来处理同类元素// Rather than doing this$('#nav li').click(function(){$('#nav li').removeClass('active');$(this).addClass('active');});// Do this instead$('#nav li').click(function(){$(this).addClass('active').siblings().removeClass('active');}); 41. 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;}); 42. 基于输入文字过滤页面元素//If the value of the element matches that of the entered text//it will be returned$('.gbin1Class').filter(function() {return $(this).attr('value') == $('input#gbin1Id').val() ;}) 43. 取得鼠标的X和Y坐标$(document).mousemove(function(e){$(document).ready(function() {$().mousemove(function(e){$('#XY').html("Gbin1 X Axis : " + e.pageX + " | Gbin1 Y Axis " + e.pageY);});}); 44. 使得整个列表元素(LI)可点击$("ul li").click(function(){_window.location=$(this).find("a").attr("href"); return false;});  45. 使用jQuery来解析XMLfunction parseXml(xml) {//find every Tutorial and print the author$(xml).find("Tutorial").each(function(){$("#output").append($(this).attr("author") + "");});} 46. 判断一个图片是否加载完全$('#theGBin1Image').attr('src', 'image.jpg').load(function() {alert('This Image Has Been Loaded');}); 47. 使用jQuery命名事件//Events can be namespaced like this$('input').bind('blur.validation', function(e){// ...});//The data method also accept namespaces$('input').data('validation.isValid', true); 48. 判断cookie是否激活或者关闭var dt = new Date();dt.setSeconds(dt.getSeconds() + 60);[xss_clean] = "cookietest=1; expires=" + dt.toGMTString();var cookiesEnabled = [xss_clean].indexOf("cookietest=") != -1;if(!cookiesEnabled){//cookies have not been enabled} 49. 强制过期cookievar date = new Date();date.setTime(date.getTime() + (x * 60 * 1000));$.cookie('example', 'foo', { expires: date }); 50. 使用一个可点击的链接替换页面中所有URL$.fn.replaceUrl = function() {var regexp = /((ftp|http|https)://(w+:{0,1}w*@)?(S+)(:[0-9]+)?(/|/([w#!:.?+=&%@!-/]))?)/gi;this.each(function() {$(this).html($(this).html().replace(regexp,'$1'));});return $(this);}//usage$('#GBin1div').replaceUrl();

以上就是jQuery代码开发技巧都有哪些,小编相信有部分知识点可能是我们日常工作会见到或用到的。希望你能通过这篇文章学到更多知识。更多详情敬请关注行业资讯频道。

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