jsevent(js event对象)

àì夳堔傛蜴生んèń 2023-09-26 14:51 21阅读 0赞

### javascript event对象的具体功能是什么 ###

event对象只在事件发生的过程中才有效(比如鼠标点击，键盘按下等)。

event对象用以表示事件的状态，

触发event对象的元素(event.srcElement)、

鼠标的位置(event.clientX、event.clientY)、

按下的键(event.keyCode)等等。

event对象的属性包括：

altKey, button, cancelBubble, clientX, clientY, ctrlKey, fromElement, keyCode, offsetX, offsetY, propertyName, returnValue, screenX, screenY, shiftKey, srcElement, srcFilter, toElement, type, x, y (可以详细查看参考书)

使用event的方法：

var evt = window.event;

FF中不能通过该方法得到event对象，可以通过传值的方法：

element.onclick = function(e)\{

var evt = window.event || e;

用event获得点击时鼠标的坐标

element.onclick = function(e)\{

var evt = window.event || e;

var cursorPOS = \{

x : evt.clientX,

y : clientY

用event对象指定当按下回车键时，弹出警告框

element.onkeydown = function(e)\{

var evt = window.event || e;

if(evt.keyCode==13)\{

alert('按下了回车！');

用event获得鼠标点击的DOM对象

document.οnclick=function(e)\{

var evt = window.event || e;

var \_target = evt.srcElement || evt.target;

alert(\_target.tagName)

更多的使用，请参考教材。event是判断对象是否为空~

event.srcelement是引发事件的目标对象 常用于onclick事件

tagname属性的作用是:返回已选元素的标签名称 你这个肯定是在里加的 所以代码上判断了是否为td

tolowercase()就是将所有大写变小写

if ( (!event) || ('td'!=event.srcelement.tagname.tolowercase()) ) return; 这句话的意思就是如果event为空或者所选的元素名称不是'td'的话就返回 不进行下边的程序了

2018-11-21

var sogou\_div\_805186 = document.getElementById("sogou\_wap\_805186");

window.sogou\_un = window.sogou\_un || \[\];

window

.sogou\_un

.push(\{id: 805186, ele: sogou\_div\_805186, w: 20, h: 20\});

window.\_gtag = window.\_gtag || \{\};

\_gtag.feedAdInfo = \{"wm12":\{"page":6,"index":1\},"wm32":\{"page":3,"index":5\},"tbt":\{"page":1,"index":2\},"wmx2":\{"page":5,"index":5\},"gdt1":\{"page":0,"index":0\},"gdt3":\{"page":0,"index":0\},"bkv":\{"page":0,"index":0\},"360":\{"page":0,"index":0\},"ta":\{"page":3,"index":1\},"tb":\{"page":0,"index":0\},"qtr":\{"page":2,"index":2\},"wmd":\{"page":0,"index":0\},"gdtx":\{"page":0,"index":0\},"zp":\{"page":0,"index":0\},"wmx1":\{"page":4,"index":3\},"wm1":\{"page":5,"index":1\},"wm3":\{"page":0,"index":0\},"gdtd":\{"page":0,"index":0\},"xxl1":\{"page":4,"index":1\},"xxl2":\{"page":4,"index":1\}\};

\_gtag.ka\_zhibo\_switch\_on = false;

\_gtag.ka\_youxi\_switch\_on = false;

\_gtag.showBKVideo = true;

window.\_gtag = window.\_gtag || \{\};

window.\_gtag.shouldGrayed = false;

window.\_gtag.logoSelector = '.nav\_logo, .nr-logo';

\_gtag.userId = '-1';

\_gtag.uid = '-1';

//灰度页tag只有一个

\_gtag.tags = '137';

\_gtag.firstTagName = 'IT技术';

\_gtag.id = '855856581';

\_gtag.query = '';

\_gtag.title = 'javascript%20event%E5%AF%B9%E8%B1%A1%E7%9A%84%E5%85%B7%E4%BD%93%E5%8A%9F%E8%83%BD%E6%98%AF%E4%BB%80%E4%B9%88';

\_gtag.traceId = '1f3432fef5574a9e8a86f9b47e54082c';

\_gtag.jumpLoginUrl = '?style=9&appid=1600000108&low\_login=0&daid=391&hln\_css=&pt\_no\_onekey=0&s\_url=http%3A%2F%2F127.0.0.1%3A8083%2Fpage%2Fold%2Fq855856581%3F\_traceid%3D1f3432fef5574a9e8a86f9b47e54082c';

\_gtag.isLogin = false

//搜索广告替换百川 & 智搜广告，10 % 灰度 - 2019.03 .20

\_gtag.grayAllow = true;

\_gtag.renderBanner = true;

//是否显示网盟广告

\_gtag.isShowWangMengAd = false;

\_gtag.uuid = "6169806575";

\_gtag.feedHotWorldGray = true;

\_gtag.adPriority = 'cd,zy,ss,gdt,wm';

\_gtag.adTBSwitch = false;

\_gtag.adGDTSwitch = true;

\_gtag.adWMSwitch = true;

\_gtag.adYMSwitch = false;

\_gtag.adCDSwitch = true;

\_gtag.adTBTSwitch = false;

\_gtag.adEBKSwitch = false;

\_gtag.adXXLSwitch = false;

\_gtag.bkInner = false;

\_gtag.adTuiaSwitch = false;

\_gtag.showTaAd = false;

//屏蔽只针对最佳答案下方的网盟广告，feed流中的网盟广告不受影响

\_gtag.showWmBrowser = true;

\_gtag.htymSwitch = false;

//qq浏览器

\_gtag.mQBUa = false;

\_gtag.h5gray = false;

//是否为qb小程序

\_gtag.miniProgramUa = false;

//porn值

\_gtag.levelInfo = '';

//自营广告

\_gtag.adSelfOperateList = \[\];

\_gtag.adWendaSelfOperateList = \[\];

//搜狗阅读banner广告

\_gtag.yueduBannerSwtich = false;

//百科搜索词

\_gtag.baikeSearchSwitch = false;

\_gtag.baikeSearchWords = \[\];

\_gtag.showRelatedSearch = true;

if (!window.\_gtag) \{

\_gtag = \{\};

\_gtag.ww\_touchstone\_info\_list = \{

'reportEnv': '2',

'hitTest': '\{"42":\{"itemId":15,"groupId":42,"layerId":0,"channelId":1,"productId":1,"report":false,"reportStatus":"0","varName":"relaquestion","varValue":"1","extParamMap":\{"pid":"sogou-waps-d85688fce6136697"\}\},"43":\{"itemId":20,"groupId":43,"layerId":0,"channelId":1,"productId":1,"report":false,"reportStatus":"0","varName":"askkey","varValue":"0","extParamMap":\{"pid":"sogou-waps-8e636fbd9b5bd3c7"\}\},"66":\{"itemId":43,"groupId":66,"layerId":0,"channelId":1,"productId":1,"report":false,"reportStatus":"0","varName":"shenmain","varValue":"0","extParamMap":\{"pid":"sogou-waps-ec88121df4e8a5ea"\}\},"69":\{"itemId":49,"groupId":69,"layerId":1,"channelId":1,"productId":1,"report":false,"reportStatus":"0","varName":"thumbStyle","varValue":"0","extParamMap":\{\}\}\}'

\};

//无线问问来源统一用254

var orig = 254;

\_gtag.orig = 254;

var ua = window

.navigator

.userAgent

.toLowerCase();

//如果是搜索app

if (/sogousearch/ig.test(ua)) \{

orig = 255;

\_gtag.orig = 255;

\_gtag.fromWeiXin = false;

![jsevent(js event对象)\_jsevent(js event对象)][jsevent_js event_jsevent_js event]

### js中event.srcElement和event.target的区别 ###

event.srcElement从字面上可以看出来有以下关键字：事件,源 他的意思就是：当前事件的源，

我们可以调用他的各种属性 就像:document.getElementById("")这样的功能，

经常有人问 firefox 下的 event.srcElement 怎么用，在此详细说明：

IE下,event对象有srcElement属性,但是没有target属性;Firefox下,event对象有target属性,但是没有srcElement属性.但他们的作用是相当的，即：

firefox 下的 event.target = IE 下的 event.srcElement触发当前事件的源对象

var a = document.getelementbyid('test');

a.addeventlistener('click', function(event) \{

//这里面event.target就是a对象

\}, false);

srcelement是ie下的属性

target是firefox下的属性

chrome浏览器同时有这两个属性event.srcElement从字面上可以看出来有以下关键字：事件,源 他的意思就是：当前事件的源， 我们可以调用他的各种属性 就像:document.getElementById("")这样的功能， 经常有人问 firefox 下的 event.srcElement 怎么用，在此详细说明： IE下,event对象有srcElement属性,但是没有target属性;Firefox下,event对象有target属性,但是没有srcElement属性.但他们的作用是相当的，即： firefox 下的 event.target = IE 下的 event.srcElement

[jsevent_js event_jsevent_js event]: https://img1.baidu.com/it/u=2792832709,3506086694&fm=26&fmt=auto