【知识碎片】JavaScript篇

40、选择器组合

逗号是多选择器
空格是子子孙孙
尖括号只找儿子

39、失去焦点事件blur

$("input").blur(function(){$("input").css("background-color","#D6D6FF");
});

38、图片延迟加载

Lozad.js

jQuery.lazyload

demo:https://apoorv.pro/lozad.js/demo/

常用JavaScript包

37、纯JS复制文本到检测板

clipboard.js

官网：https://clipboardjs.com/

GIT：https://github.com/zenorocha/clipboard.js/archive/master.zip

36、二维码JS库

https://github.com/xiaoshi657/qrcodejs

<div id="qrcode"></div>
<script type="text/javascript">
new QRCode(document.getElementById("qrcode"), "http://jindo.dev.naver.com/collie");
</script>

35、jquery中ifram子窗体调用父窗体方法、父窗体调用子窗体方法

//调用子窗体中的方法.var childWindow = $("#AddFrame")[0].contentWindow;//获取子窗体的window对象
childWindow.subForm();//调用父窗体中的方法window.parent.afterAdd();

34、省市联动遍历json数组

 //地址改变事件$("#ProvinceCode").change(function (e) {$.ajax({type: "POST",url: "/usercenter/uaccount/getcitylist",data: {provinceCode:$("#ProvinceCode").val()},success: function (result) {//result :[{"ID":127,"Code":"360100","Name":"南昌市","ProvinceCode":"360000"},{"ID":128,"Code":"360200","Name":"景德镇市","ProvinceCode":"360000"}]var tempHtml="";for (var i in result) {tempHtml+='<option value="'+result[i].Code+'">'+result[i].Name+'</option>';}$("#CityCode").html(tempHtml);},dataTypeString: "json"});

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c#代码：

  public ActionResult GetCityList(string provinceCode){List<S_City> cityList = CacheHelper.GetCache("CityCache") as List<S_City>;if (cityList == null){XS.EasyBlog.BLL.S_CityService citybll = new BLL.S_CityService();cityList = citybll.LoadEntities(c => true).ToList();CacheHelper.SetCache("CityCache", cityList);}cityList = cityList.Where(c => c.ProvinceCode == provinceCode).ToList();//ViewBag.CityList = cityList;return Json(cityList, JsonRequestBehavior.AllowGet);//return View(CurrentMember);}

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33、获取form表单所有值

    $("#commitInfoForm").click(function () {alert($("#accountInfoForm").serialize());//.serializeArray();});

键值对：

$("button").click(function(){x=$("form").serializeArray();$.each(x, function(i, field){$("#results").append(field.name + ":" + field.value + " ");});
});

32、json转换

var obj = eval('(' + str + ')');
var last=JSON.stringify(obj); //将JSON对象转化为string字符

31、IE8屏蔽错误

重写方法

    window.onerror = function () { return true; }console.log = function () { };console.error = function () { };

<script>window.console = window.console || (function () {var c = {}; c.log = c.warn = c.debug = c.info = c.error = c.time = c.dir = c.profile= c.clear = c.exception = c.trace = c.assert = function () { };return c;})();
</script>

30、jqzoom.js 图片放大器

SWFUpload 文件上传

29、数组中存在则移除

AddMemberIDList.splice($.inArray(MemberID, AddMemberIDList), 1);
//1:移除的次数这里指一次  0：不移除

28、可以关闭的小广告

var dvObj = $('<div style="width:300px; height:200px;position:absolute;right:0;bottom:0;"></div>').appendTo($('body')); //层来了//可以关闭广告$('<span style="float:right; cursor:pointer;">×</span>').click(function () {$(this).parent().remove();}).appendTo(dvObj);

27、请仔细阅读协议

        $(function () {var sec = 5;var setId = setInterval(function () {sec--;if (sec <= 0) {sec = 0; clearInterval(setId); $('#btn').val('同意').attr('disabled',false); } else { $('#btn').val('请仔细阅读协议(' + sec + ')'); } }, 1000); });

26、jq的cookie处理 jquery.cookie.js

1、引用 jquery.cookie.js

2、用下面这段代码两个方式都很好用

//写cookies
function setCookie(name, value,time) {var Days = time||365;var exp = new Date();exp.setTime(exp.getTime() + Days * 24 * 60 * 60 * 1000);document.cookie=name+"="+escape(value)+";expires="+exp.toGMTString()+";path=/;";
}
//读取cookies
function getCookie(sName) {var aCookie = document.cookie.split("; ");for (var i = 0; i < aCookie.length; i++) {var aCrumb = aCookie[i].split("=");if (sName == aCrumb[0])return unescape(aCrumb[1]);}return null;
}//删除cookies
function delCookie(name) {var exp = new Date();exp.setTime(exp.getTime() + -1 * 24 * 60 * 60 * 1000);var cval = getCookie(name);if (cval != null)document.cookie = name + "=;expires=" + exp.toGMTString() + "; path=/;";
}
//清楚所有cookie
function clareCookie() {var strCookie = document.cookie;var arrCookie = strCookie.split("; "); // 将多cookie切割为多个名/值对for (var i = 0; i < arrCookie.length; i++) { // 遍历cookie数组，处理每个cookie对var arr = arrCookie[i].split("=");if (arr.length > 0)delCookie(arr[0]);}
}

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//创建一个超链接添加到body中
$('<a href="http://www.baidu.com"></a>').text('百度').appendTo($('body'));//在body中添加超链接// var akObj = $('<a href="http://www.baidu.com"></a>').text('百度');// $('body').append(akObj);

              //表示的是包含哈哈这两个字的内容的层//$('div:contains(哈哈)').css('fontSize','100px');//空层//$('div:empty').css('backgroundColor', 'pink');//所有DIV中包含a标签的div北京为蓝色$('div:has(a)').css('backgroundColor', 'pink');

25、循环遍历checkbox /radio

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head><title></title><script src="jquery-1.8.3.js" type="text/javascript"></script><script type="text/javascript">$(function () {$('#btn').click(function () {var cks = $('div input:checked');//元素的each用法
                cks.each(function (index, ele) {alert($(ele).val());});});});</script>
</head>
<body><input type="button" name="name" value="显示value值" id="btn" /><div id="dv"><input type="checkbox" name="name" value="1" />吃饭<input type="checkbox" name="name" value="2" />睡觉<input type="checkbox" name="name" value="3" />打豆豆<input type="checkbox" name="name" value="4" />打篮球<input type="checkbox" name="name" value="5" />打足球<input type="checkbox" name="name" value="6" />打铅球</div>
</body>
</html>

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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head><title></title><script src="jquery-1.8.3.js" type="text/javascript"></script><script type="text/javascript">$(function () {//全选
            $('#btnAll').click(function () {$('div :checkbox').attr('checked', true);});//全不选
            $('#btnNoAll').click(function () {$('div :checkbox').attr('checked', false);});//反选
            $('#btnFX').click(function () {$('div :checkbox').each(function (index, ele) {$(ele).attr('checked', !$(ele).attr('checked'));});});});</script>
</head>
<body><input type="button" name="name" value="全选" id="btnAll" /><input type="button" name="name" value="全不选" id="btnNoAll" /><input type="button" name="name" value="反选" id="btnFX" /><div style="border: 1px solid red; height: 200px;"><input type="checkbox" name="name" value="1" />忐忑<input type="checkbox" name="name" value="2" />法海不懂爱<input type="checkbox" name="name" value="3" />金箍棒<input type="checkbox" name="name" value="4" />爱情买卖<input type="checkbox" name="name" value="5" />最炫民族风</div>
</body>
</html>

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<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>Title</title>
</head>
<body><input type="button" value="全选" onclick="checkAll();" /><input type="button" value="反选" onclick="reverseAll();" /><input type="button" value="取消"  onclick="cancleAll();"/><table border="1"><thead><tr><th>选项</th><th>IP</th><th>PORT</th></tr></thead><tbody id="tb"><tr><td><input type="checkbox" /></td><td>1.1.1.1</td><td>80</td></tr><tr><td><input type="checkbox" /></td><td>1.1.1.1</td><td>80</td></tr><tr><td><input type="checkbox" /></td><td>1.1.1.1</td><td>80</td></tr></tbody></table><script src="jquery-1.12.4.js"></script><script>function checkAll() {$('#tb :checkbox').prop('checked',true);}function cancleAll() {$('#tb :checkbox').prop('checked',false);}function reverseAll() {$(':checkbox').each(function(k){// this,代指当前循环的每一个元素// Dom/*if(this.checked){this.checked = false;}else{this.checked = true;}*//*if($(this).prop('checked')){$(this).prop('checked', false);}else{$(this).prop('checked', true);}*/// 三元运算var v = 条件? 真值：假值// var v = $(this).prop('checked');//?false:true;
                $(this).prop('checked',!$(this).prop('checked'));})}</script>
</body>
</html>

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24、获取被选中的checked input

$('input:checked').css('backgroundColor', 'red');//获取 被选中的元素

<div><input type="checkbox" name="name" value="1" checked="checked" />吃饭<input type="checkbox" name="name" value="2"  checked="checked" />睡觉<input type="checkbox" name="name" value="3" />打豆豆</div>

23、两个加载的区别onload

onload $(document).ready(function (){}) 区别

前者是图片类资源都加载完执行

或者是基本标签加载完执行

前者只可以写一个，多写后面的会覆盖前面的，后者写多少个执行多少个

后者的终极写法

$(function (){})
$(document).ready(function (){})
//与
$(function (){})
//功能一样都是加载完执行

22、JS正则

var patt1=new RegExp("e");
document.write(patt1.test("The best things in life are free"));
//返回true //RegExp 对象有 3 个方法：test()、exec() 以及 compile()//返回bool、返回匹配到的字符

var msg= "      去掉空格      " msg = msg.replace(/^\s+/g, '');// \s空格

正则表达式中/i,/g,/ig,/gi,/m的区别和含义

/i (忽略大小写)
/g (全文查找出现的所有匹配字符)
/m (多行查找)
/gi(全文查找、忽略大小写)
/ig(全文查找、忽略大小写)

21、js 随机数整数

$(document).ready(function() {    //x上限，y下限    var x = 12;       var y = 0;           var rand = parseInt(Math.random() * (x - y + 1) + y);      $("#b").html("").append("<div>" + rand + "</div>");    })

从1开始至任意值

parseInt(Math.random()*上限+1);

2. 从任意值开始至任意值

parseInt(Math.random()*(上限-下限+1)+下限);

random是0到1之间(不包括1)的伪随机函数,floor是取当前数值的整数部分值,舍掉小数部分.

常搭配使用,用来取0到某个数值之间的随机数.如想取0~49之间的随机数可用:

Math.floor(Math.random()*50),最大值再大也不到50,后舍掉小数部分就是0~49的任意一个伪随机数.

round是取近似值的数,也就是四舍五入的说法.返回一个整数值,配合使用如:

Math.round(Math.atan2(y,x))来返回一个角度的近似整数值

20、判断是否为空

**判断是否null
*@param data
*/
function isNull(data) {return (data == "" || data == undefined || data == null);
}

var companyid = new URL().get('CompanyID');
if (companyid != null || companyid != "" || companyid != undefined) {

19、去掉最后逗号

chk_id = chk_id.substr(0, chk_id.length - 1);//去掉最后“,”

18、去掉html

                        $("#" + id).parent().parent().remove();

17、setInterval(循环) setTimeout(一次)定时执行

//--------监测UUID  start-------//每0.1秒检查一次字符串前34个字符是否等于tvalue如果不等于就重新赋值，var tValue = "4F9863FE-96DA-4AB0-AA31-6FE7475A60";var intv setInterval(function (event) {var value = document.getElementById("UUID").value;var val_34 = value.substr(0, 34);//获取前34位//var val_2 = value.subStr(value.length - 2, 2);//获取后两位if (val_34 != tValue) {document.getElementById("UUID").value = $("#hidUUID").val();}}, 100);//---------监测UUID   end--------    //window.clearInterval(intv) //移除

16、setTimeout

setTimeout("alert('5 seconds!')",5000)

15、判断数组中是否存在指定元素

                        //if (MemberIDList.indexOf(_model.FriendID) >= 0) {//    _model.Display = "display:none";//};if ($.inArray(_model.FriendID, MemberIDList)>=0) {_model.Display = "display:none";};

14、checkeBox 限制单选

//$("#myCheckBox").bind('change',function(){});

//$("#myCheckBox").change(function(){})

//限制单选$("input[name='kt']:checkbox").live("click", function () {//$("input[name='kt']").each(function () {//    $(this).attr('checked', false);//});//$(this).attr('checked', true);if ($(this).is(':checked')) {//alert($(this).attr('checked'))$(this).attr('checked', true).parent().parent().siblings().children().children().attr('checked', false);} else {$(this).attr('checked', false).parent().parent().siblings().children().children().attr('checked', false);}})

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