如果你的网页中需要使用大量初始不可见的（例如，悬停的）图像，那么可以预加载这些图像。
$.preloadImages = function () { for (var i = 0; i < argument.length; i ++) { $('<imag>').attr('src', argument[i]); } }; $.preloadImages('img/a.png', 'img/b.png'); 有时为了继续脚本，你可能需要检查图像是否全部加载完毕。
$('img').load(function () { console.log('image load succeed'); }); //你也可以使用 ID 或 CLASS 替换<img> 标签来检查某个特定的图像是否被加载。 逐个替换已经破坏的图像链接是非常痛苦的。不过，下面这段简单的代码可以帮助你。
$('img').on('error', function () { if(!$(this).hasClass('broken-image')){ $(this).prop('src', 'img/a.png').addClass('broken-image'); } }); 当用户鼠标悬停在可点击的元素上时，可添加类到元素中，反之则移除类。
$(selector).hover(function () { $(this).addClass('hover'); }),function () { $(this).removeClass('hover'); }; //或 $(selector).hover(function () { $(this).toggleClass('hover'); }); $('.btn').click(function () { $('.element').fadeToggle('slow'); }); $('.btn').click(function () { $('.element').slideToggle('slow'); }); $('#content').on("mousewheel DOMMouseScroll", function (event) { // chrome & ie || // firefox var delta = (event.originalEvent.wheelDelta && (event.originalEvent.wheelDelta > 0 ? 1 : -1)) || (event.originalEvent.detail && (event.originalEvent.detail > 0 ? -1 : 1)); if (delta > 0) { console.log('mousewheel top'); } else if (delta < 0) { console.log('mousewheel bottom'); } }); 1、JavaScript实现
<body> X:<input id="xxx" type="text" /> Y:<input id="yyy" type="text" /> </body> <script> function mousePosition(ev){ if(ev.pageX || ev.pageY){ return {x:ev.pageX, y:ev.pageY}; } return { x:ev.clientX + document.body.scrollLeft - document.body.clientLeft, y:ev.clientY + document.body.scrollTop - document.body.clientTop }; } function mouseMove(ev){ ev = ev || window.event; var mousePos = mousePosition(ev); document.getElementById('xxx').value = mousePos.x; document.getElementById('yyy').value = mousePos.y; } document.onmousemove = mouseMove; </script> 2、jQuery实现
$('#ele').click(function(event){ //获取鼠标在图片上的坐标 console.log('X：' + event.offsetX+'\n Y:' + event.offsetY); //获取元素相对于页面的坐标 console.log('X：' + $(this).offset().left + '\n Y:'+$(this).offset().top); }); 1、HTML实现
<body ontouchmove="event.preventDefault()" > 2、JavaScript实现
document.addEventListener('touchmove', function(event) { event.preventDefault(); }); // JavaScript document.getElementById('btn').addEventListener('click', function (event) { event = event || window.event； if (event.preventDefault){ // W3C event.preventDefault(); } else{ // IE event.returnValue = false; } }, false); // jQuery $('#btn').on('click', function (event) { event.preventDefault(); }); // JavaScript document.getElementById('btn').addEventListener('click', function (event) { event = event || window.event； if (event.stopPropagation){ // W3C event.stopPropagation(); } else{ // IE event.cancelBubble = true; } }, false); // jQuery $('#btn').on('click', function (event) { event.stopPropagation(); }); function isSupportSVG() { var SVG_NS = 'http://www.w3.org/2000/svg'; return !!document.createElementNS &&!!document.createElementNS(SVG_NS, 'svg').createSVGRect; } console.log(isSupportSVG()); function isSupportCanvas() { if(document.createElement('canvas').getContext){ return true; }else{ return false; } } console.log(isSupportCanvas()); function isWeiXinClient() {
var ua = navigator.userAgent.toLowerCase();
if (ua.match(/MicroMessenger/i)==“micromessenger”) {
return true;
} else {
return false;
}
}
alert(isWeiXinClient());
var browser = { versions: function() { var u = navigator.userAgent; return { trident: u.indexOf('Trident') > -1, //IE内核 presto: u.indexOf('Presto') > -1, //opera内核 webKit: u.indexOf('AppleWebKit') > -1, //苹果、谷歌内核 gecko: u.indexOf('Firefox') > -1, //火狐内核Gecko mobile: !!u.match(/AppleWebKit.*Mobile.*/), //是否移动终端 ios: !!u.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/), //ios android: u.indexOf('Android') > -1 || u.indexOf('Linux') > -1, //android iPhone: u.indexOf('iPhone') > -1 , //iPhone iPad: u.indexOf('iPad') > -1, //iPad webApp: u.indexOf('Safari') > -1 //Safari }; } } if (browser.versions.mobile() || browser.versions.ios() || browser.versions.android() || browser.versions.iPhone() || browser.versions.iPad()) { alert('移动端'); } var browser={ versions:function(){ var u = navigator.userAgent, app = navigator.appVersion; var sUserAgent = navigator.userAgent; return { trident: u.indexOf('Trident') > -1, presto: u.indexOf('Presto') > -1, isChrome: u.indexOf("chrome") > -1, isSafari: !u.indexOf("chrome") > -1 && (/webkit|khtml/).test(u), isSafari3: !u.indexOf("chrome") > -1 && (/webkit|khtml/).test(u) && u.indexOf('webkit/5') != -1, webKit: u.indexOf('AppleWebKit') > -1, gecko: u.indexOf('Gecko') > -1 && u.indexOf('KHTML') == -1, mobile: !!u.match(/AppleWebKit.*Mobile.*/), ios: !!u.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/), android: u.indexOf('Android') > -1 || u.indexOf('Linux') > -1, iPhone: u.indexOf('iPhone') > -1, iPad: u.indexOf('iPad') > -1, iWinPhone: u.indexOf('Windows Phone') > -1 }; }() } if(browser.versions.mobile || browser.versions.iWinPhone){ window.location = "http:/www.baidu.com/m/"; } function getInternet(){ if(navigator.userAgent.indexOf("MSIE")>0) { return "MSIE"; //IE浏览器 } if(isFirefox=navigator.userAgent.indexOf("Firefox")>0){ return "Firefox"; //Firefox浏览器 } if(isSafari=navigator.userAgent.indexOf("Safari")>0) { return "Safari"; //Safan浏览器 } if(isCamino=navigator.userAgent.indexOf("Camino")>0){ return "Camino"; //Camino浏览器 } if(isMozilla=navigator.userAgent.indexOf("Gecko/")>0){ return "Gecko"; //Gecko浏览器 } } $( window ).on( "orientationchange", function( event ) { if (event.orientation=='portrait') { $('body').css('transform', 'rotate(90deg)'); } else { $('body').css('transform', 'rotate(0deg)'); } }); $( window ).orientationchange(); function fullscreen(element) { if (element.requestFullscreen) { element.requestFullscreen(); } else if (element.mozRequestFullScreen) { element.mozRequestFullScreen(); } else if (element.webkitRequestFullscreen) { element.webkitRequestFullscreen(); } else if (element.msRequestFullscreen) { element.msRequestFullscreen(); } } fullscreen(document.documentElement); 1、JavaScript实现
<body> <input id="i_input" type="text" value="会员卡号/手机号"/> </body> <script> // JavaScript window.onload = function(){ var oIpt = document.getElementById("i_input"); if(oIpt.value == "会员卡号/手机号"){ oIpt.style.color = "#888"; }else{ oIpt.style.color = "#000"; }; oIpt.onfocus = function(){ if(this.value == "会员卡号/手机号"){ this.value=""; this.style.color = "#000"; this.type = "password"; }else{ this.style.color = "#000"; } }; oIpt.onblur = function(){ if(this.value == ""){ this.value="会员卡号/手机号"; this.style.color = "#888"; this.type = "text"; } }; } </script> 2、jQuery实现
<body> <input type="text" class="oldpsw" id="showPwd" value="请输入您的注册密码"/> <input type="password" name="psw" class="oldpsw" id="password" value="" style="display:none;"/> </body> <script> // jQuery $("#showPwd").focus(function() { var text_value=$(this).val(); if (text_value =='请输入您的注册密码') { $("#showPwd").hide(); $("#password").show().focus(); } }); $("#password").blur(function() { var text_value = $(this).val(); if (text_value == "") { $("#showPwd").show(); $("#password").hide(); } }); </script> <body> <input type="file" id="filePath" onchange="getFileSize(this)"/> </body> <script> // 兼容IE9低版本 function getFileSize(obj){ var filesize; if(obj.files){ filesize = obj.files[0].size; }else{ try{ var path,fso; path = document.getElementById('filePath').value; fso = new ActiveXObject("Scripting.FileSystemObject"); filesize = fso.GetFile(path).size; } catch(e){ // 在IE9及低版本浏览器，如果不容许ActiveX控件与页面交互，点击了否，就无法获取size console.log(e.message); // Automation 服务器不能创建对象 filesize = 'error'; // 无法获取 } } return filesize; } </script> 1、高版本浏览器
<input type="file" name="filePath" accept=".jpg,.jpeg,.doc,.docxs,.pdf"/> 2、限制图片
<input type="file" class="file" value="上传" accept="image/*"> 3、低版本浏览器
<input type="file" id="filePath" onchange="limitTypes()"> /* 通过扩展名，检验文件格式。 * @parma filePath{string} 文件路径 * @parma acceptFormat{Array} 允许的文件类型 * @result 返回值{Boolen}：true or false */ function checkFormat(filePath,acceptFormat){ var resultBool= false, ex = filePath.substring(filePath.lastIndexOf('.') + 1); ex = ex.toLowerCase(); for(var i = 0; i < acceptFormat.length; i++){ if(acceptFormat[i] == ex){ resultBool = true; break; } } return resultBool; }; function limitTypes(){ var obj = document.getElementById('filePath'); var path = obj.value; var result = checkFormat(path,['bmp','jpg','jpeg','png']); if(!result){ alert('上传类型错误，请重新上传'); obj.value = ''; } } //验证邮箱 /^\w+@([0-9a-zA-Z]+[.])+[a-z]{2,4}$/ //验证手机号 /^1[3|5|8|7]\d{9}$/ //验证URL /^http:\/\/.+\./ //验证身份证号码 /(^\d{15}$)|(^\d{17}([0-9]|X|x)$)/ //匹配字母、数字、中文字符 /^([A-Za-z0-9]|[\u4e00-\u9fa5])*$/ //匹配中文字符 /[\u4e00-\u9fa5]/ //匹配双字节字符(包括汉字) /[^\x00-\xff]/ <body> <input id="txt" type="text"> </body> <script> //字符串截取 function getByteVal(val, max) { var returnValue = ''; var byteValLen = 0; for (var i = 0; i < val.length; i++) { if (val[i].match(/[^\x00-\xff]/ig) != null) byteValLen += 2; else byteValLen += 1; if (byteValLen > max) break; returnValue += val[i]; } return returnValue; } $('#txt').on('keyup', function () { var val = this.value; if (val.replace(/[^\x00-\xff]/g, "**").length > 14) { this.value = getByteVal(val, 14); } }); </script> 1、JavaScript实现
<body> <input id="send" type="button" value="发送验证码"> </body> <script> // JavaScript var times = 60, // 时间设置60秒 timer = null; document.getElementById('send').onclick = function () { // 计时开始 timer = setInterval(function () { times--; if (times <= 0) { send.value = '发送验证码'; clearInterval(timer); send.disabled = false; times = 60; } else { send.value = times + '秒后重试'; send.disabled = true; } }, 1000); } </script> 2、jQuery实现
var times = 60, timer = null; $('#send').on('click', function () { var $this = $(this); // 计时开始 timer = setInterval(function () { times--; if (times <= 0) { $this.val('发送验证码'); clearInterval(timer); $this.attr('disabled', false); times = 60; } else { $this.val(times + '秒后重试'); $this.attr('disabled', true); } }, 1000); }); <body> <p id="_lefttime"></p> </body> <script> var times = 60, timer = null; $('#send').on('click', function () { var $this = $(this); // 计时开始 timer = setInterval(function () { times--; if (times <= 0) { $this.val('发送验证码'); clearInterval(timer); $this.attr('disabled', false); times = 60; } else { $this.val(times + '秒后重试'); $this.attr('disabled', true); } }, 1000); }); </script> <body> <div id="showtimes"></div><div id="showtimes"></div> </body> <script> // 设置倒计时秒数 var t = 10; // 显示倒计时秒数 function showTime(){ t -= 1; document.getElementById('showtimes').innerHTML= t; if(t==0){ location.href='error404.asp'; } //每秒执行一次 showTime() setTimeout("showTime()",1000); } showTime(); </script> function formatDate(now) { var y = now.getFullYear(); var m = now.getMonth() + 1; // 注意 JavaScript 月份+1 var d = now.getDate(); var h = now.getHours(); var m = now.getMinutes(); var s = now.getSeconds(); return y + "-" + m + "-" + d + " " + h + ":" + m + ":" + s; } var nowDate = new Date(1442978789184); alert(formatDate(nowDate)); var calculateDate = function(){ var date = new Date(); var weeks = ["日","一","二","三","四","五","六"]; return date.getFullYear()+"年"+(date.getMonth()+1)+"月"+ date.getDate()+"日 星期"+weeks[date.getDay()]; } $(function(){ $("#dateSpan").html(calculateDate()); }); <body> <p id="text"></p> </body> <script> function time(y,m){ var tempTime = new Date(y,m,0); var time = new Date(); var saturday = new Array(); var sunday = new Array(); for(var i=1;i<=tempTime.getDate();i++){ time.setFullYear(y,m-1,i); var day = time.getDay(); if(day == 6){ saturday.push(i); }else if(day == 0){ sunday.push(i); } } var text = y + "年" + m + "月份" + "<br />" + "周六：" + saturday.toString() + "<br />" + "周日：" + sunday.toString(); document.getElementById("text").innerHTML = text; } time(2018,5); </script> 当 Ajax 调用返回 404 或 500 错误时，就执行错误处理程序。如果没有定义处理程序，其他的 jQuery 代码或会就此罢工。定义一个全局的 Ajax 错误处理程序
$(document).ajaxError(function (e, xhr, settings, error) { console.log(error); });