事件(Event)是JavaScript應(yīng)用跳動(dòng)的心臟 ，也是把所有東西粘在一起的膠水。當(dāng)我們與瀏覽器中 Web 頁(yè)面進(jìn)行某些類(lèi)型的交互時(shí)，事件就發(fā)生了。事件可能是用戶在某些內(nèi)容上的點(diǎn)擊、鼠標(biāo)經(jīng)過(guò)某個(gè)特定元素或按下鍵盤(pán)上的某些按鍵。事件還可能是 Web 瀏覽器中發(fā)生的事情，比如說(shuō)某個(gè) Web 頁(yè)面加載完成，或者是用戶滾動(dòng)窗口或改變窗口大小。
通過(guò)使用 JavaScript ，你可以監(jiān)聽(tīng)特定事件的發(fā)生，并規(guī)定讓某些事件發(fā)生以對(duì)這些事件做出響應(yīng)。
一、添加事件監(jiān)聽(tīng)
IE:
代碼如下:
attachEvent("onclick",function(){...}) //添加
detachEvent("onclick",function(){...}) //刪除
FF:
代碼如下:
addEventListener("click",function(){...},false)
//可以跟一個(gè)對(duì)象添加多個(gè)事件監(jiān)聽(tīng)，跟默認(rèn)的對(duì)象事件不同
removeEventListenner("click",function(){...},false)
二、得到事件對(duì)象
IE:
代碼如下:
op.onClick=function(){
ver oevent = window.event; //作為window的一個(gè)屬性
}
FF：
代碼如下:
op.onClick=function(oevent){
.... //通過(guò)傳入?yún)?shù)來(lái)控制
}
通用：
代碼如下:
op.onClick=function(oevent){
if(window.event){
oevent=window.event;
}
}
//即時(shí)得到了通用的，但是他們返回對(duì)象的屬性和方法也不盡一致，但可以使用通過(guò)EventUtil來(lái)解決！
代碼如下:
var EventUtil = new Object;
/**//*
此方法用來(lái)給特定對(duì)象添加事件，oTarget是指定對(duì)象,sEventType是事件類(lèi)型，如click、keydown等， fnHandler是事件回調(diào)函數(shù)
*/
EventUtil.addEventHandler = function (oTarget, sEventType, fnHandler) {
//firefox情況下
if (oTarget.addEventListener) {
oTarget.addEventListener(sEventType, fnHandler, false);
}
//IE下
else if (oTarget.attachEvent) {
oTarget.attachEvent("on" + sEventType, fnHandler);
}
else {
oTarget["on" + sEventType] = fnHandler;
}
};
/*
此方法用來(lái)移除特定對(duì)象的特定事件，oTarget是指定對(duì)象,sEventType是事件類(lèi)型，如click、keydown等，fnHandler是事件回調(diào)函數(shù)
*/
EventUtil.removeEventHandler = function (oTarget, sEventType, fnHandler) {
if (oTarget.removeEventListener) {
oTarget.removeEventListener(sEventType, fnHandler, false);
} else if (oTarget.detachEvent) {
oTarget.detachEvent("on" + sEventType, fnHandler);
} else {
oTarget["on" + sEventType] = null;
}
};
/*
格式化事件，因?yàn)镮E和其他瀏覽器下獲取事件的方式不同并且事件的屬性也不盡相同，通過(guò)此方法提供一個(gè)一致的事件
*/
EventUtil.formatEvent = function (oEvent) {
//isIE和isWin引用到一個(gè)js文件，判斷瀏覽器和操作系統(tǒng)類(lèi)型
if (isIE && isWin) {
oEvent.charCode = (oEvent.type == "keypress") ? oEvent.keyCode : 0;
//IE只支持冒泡，不支持捕獲
oEvent.eventPhase = 2;
oEvent.isChar = (oEvent.charCode > 0);
oEvent.pageX = oEvent.clientX + document.body.scrollLeft;
oEvent.pageY = oEvent.clientY + document.body.scrollTop;
//阻止事件的默認(rèn)行為
oEvent.preventDefault = function () {
this.returnValue = false;
};
//將toElement,fromElement轉(zhuǎn)化為標(biāo)準(zhǔn)的relatedTarget
if (oEvent.type == "mouseout") {
oEvent.relatedTarget = oEvent.toElement;
} else if (oEvent.type == "mouseover") {
oEvent.relatedTarget = oEvent.fromElement;
}
//取消冒泡
oEvent.stopPropagation = function () {
this.cancelBubble = true;
};
oEvent.target = oEvent.srcElement;
//添加事件發(fā)生時(shí)間屬性，IE沒(méi)有
oEvent.time = (new Date).getTime();
}
return oEvent;
};
EventUtil.getEvent = function() {
if (window.event) {
//格式化IE的事件
return this.formatEvent(window.event);
} else {
return EventUtil.getEvent.caller.arguments[0];
}
};
代碼如下:
/*
*附帶上一個(gè)判斷瀏覽器和系統(tǒng)類(lèi)型的js文件，通過(guò)引入一些名字顯而易見(jiàn)的全局變量作為判斷的結(jié)果，使用時(shí)需要小心變量名稱(chēng)沖突：
*/
var sUserAgent = navigator.userAgent;
var fAppVersion = parseFloat(navigator.appVersion);
function compareVersions(sVersion1, sVersion2) {
var aVersion1 = sVersion1.split(".");
var aVersion2 = sVersion2.split(".");
if (aVersion1.length > aVersion2.length) {
for (var i=0; i < aVersion1.length - aVersion2.length; i++) {
aVersion2.push("0");
}
} else if (aVersion1.length < aVersion2.length) {
for (var i=0; i < aVersion2.length - aVersion1.length; i++) {
aVersion1.push("0");
}
}
for (var i=0; i < aVersion1.length; i++) {
if (aVersion1[i] < aVersion2[i]) {
return -1;
} else if (aVersion1[i] > aVersion2[i]) {
return 1;
}
}
return 0;
}
var isOpera = sUserAgent.indexOf("Opera") > -1;
var isMinOpera4 = isMinOpera5 = isMinOpera6 = isMinOpera7 = isMinOpera7_5 = false;
if (isOpera) {
var fOperaVersion;
if(navigator.appName == "Opera") {
fOperaVersion = fAppVersion;
} else {
var reOperaVersion = new RegExp("Opera (//d+//.//d+)");
reOperaVersion.test(sUserAgent);
fOperaVersion = parseFloat(RegExp["$1"]);
}
isMinOpera4 = fOperaVersion >= 4;
isMinOpera5 = fOperaVersion >= 5;
isMinOpera6 = fOperaVersion >= 6;
isMinOpera7 = fOperaVersion >= 7;
isMinOpera7_5 = fOperaVersion >= 7.5;
}
var isKHTML = sUserAgent.indexOf("KHTML") > -1
|| sUserAgent.indexOf("Konqueror") > -1
|| sUserAgent.indexOf("AppleWebKit") > -1;
var isMinSafari1 = isMinSafari1_2 = false;
var isMinKonq2_2 = isMinKonq3 = isMinKonq3_1 = isMinKonq3_2 = false;
if (isKHTML) {
isSafari = sUserAgent.indexOf("AppleWebKit") > -1;
isKonq = sUserAgent.indexOf("Konqueror") > -1;
if (isSafari) {
var reAppleWebKit = new RegExp("AppleWebKit///(//d+(?://.//d*)?)");
reAppleWebKit.test(sUserAgent);
var fAppleWebKitVersion = parseFloat(RegExp["$1"]);
isMinSafari1 = fAppleWebKitVersion >= 85;
isMinSafari1_2 = fAppleWebKitVersion >= 124;
} else if (isKonq) {
var reKonq = new RegExp("Konqueror///(//d+(?://.//d+(?://.//d)?)?)");
reKonq.test(sUserAgent);
isMinKonq2_2 = compareVersions(RegExp["$1"], "2.2") >= 0;
isMinKonq3 = compareVersions(RegExp["$1"], "3.0") >= 0;
isMinKonq3_1 = compareVersions(RegExp["$1"], "3.1") >= 0;
isMinKonq3_2 = compareVersions(RegExp["$1"], "3.2") >= 0;
}
}
var isIE = sUserAgent.indexOf("compatible") > -1
&& sUserAgent.indexOf("MSIE") > -1
&& !isOpera;
var isMinIE4 = isMinIE5 = isMinIE5_5 = isMinIE6 = false;
if (isIE) {
var reIE = new RegExp("MSIE (//d+//.//d+);");
reIE.test(sUserAgent);
var fIEVersion = parseFloat(RegExp["$1"]);
isMinIE4 = fIEVersion >= 4;
isMinIE5 = fIEVersion >= 5;
isMinIE5_5 = fIEVersion >= 5.5;
isMinIE6 = fIEVersion >= 6.0;
}
var isMoz = sUserAgent.indexOf("Gecko") > -1
&& !isKHTML;
var isMinMoz1 = sMinMoz1_4 = isMinMoz1_5 = false;
if (isMoz) {
var reMoz = new RegExp("rv:(//d+//.//d+(?://.//d+)?)");
reMoz.test(sUserAgent);
isMinMoz1 = compareVersions(RegExp["$1"], "1.0") >= 0;
isMinMoz1_4 = compareVersions(RegExp["$1"], "1.4") >= 0;
isMinMoz1_5 = compareVersions(RegExp["$1"], "1.5") >= 0;
}
var isNS4 = !isIE && !isOpera && !isMoz && !isKHTML
&& (sUserAgent.indexOf("Mozilla") == 0)
&& (navigator.appName == "Netscape")
&& (fAppVersion >= 4.0 && fAppVersion < 5.0);
var isMinNS4 = isMinNS4_5 = isMinNS4_7 = isMinNS4_8 = false;
if (isNS4) {
isMinNS4 = true;
isMinNS4_5 = fAppVersion >= 4.5;
isMinNS4_7 = fAppVersion >= 4.7;
isMinNS4_8 = fAppVersion >= 4.8;
}
var isWin = (navigator.platform == "Win32") || (navigator.platform == "Windows");
var isMac = (navigator.platform == "Mac68K") || (navigator.platform == "MacPPC")
|| (navigator.platform == "Macintosh");
var isUnix = (navigator.platform == "X11") && !isWin && !isMac;
var isWin95 = isWin98 = isWinNT4 = isWin2K = isWinME = isWinXP = false;
var isMac68K = isMacPPC = false;
var isSunOS = isMinSunOS4 = isMinSunOS5 = isMinSunOS5_5 = false;
if (isWin) {
isWin95 = sUserAgent.indexOf("Win95") > -1
|| sUserAgent.indexOf("Windows 95") > -1;
isWin98 = sUserAgent.indexOf("Win98") > -1
|| sUserAgent.indexOf("Windows 98") > -1;
isWinME = sUserAgent.indexOf("Win 9x 4.90") > -1
|| sUserAgent.indexOf("Windows ME") > -1;
isWin2K = sUserAgent.indexOf("Windows NT 5.0") > -1
|| sUserAgent.indexOf("Windows 2000") > -1;
isWinXP = sUserAgent.indexOf("Windows NT 5.1") > -1
|| sUserAgent.indexOf("Windows XP") > -1;
isWinNT4 = sUserAgent.indexOf("WinNT") > -1
|| sUserAgent.indexOf("Windows NT") > -1
|| sUserAgent.indexOf("WinNT4.0") > -1
|| sUserAgent.indexOf("Windows NT 4.0") > -1
&& (!isWinME && !isWin2K && !isWinXP);
}
if (isMac) {
isMac68K = sUserAgent.indexOf("Mac_68000") > -1
|| sUserAgent.indexOf("68K") > -1;
isMacPPC = sUserAgent.indexOf("Mac_PowerPC") > -1
|| sUserAgent.indexOf("PPC") > -1;
}
if (isUnix) {
isSunOS = sUserAgent.indexOf("SunOS") > -1;
if (isSunOS) {
var reSunOS = new RegExp("SunOS (//d+//.//d+(?://.//d+)?)");
reSunOS.test(sUserAgent);
isMinSunOS4 = compareVersions(RegExp["$1"], "4.0") >= 0;
isMinSunOS5 = compareVersions(RegExp["$1"], "5.0") >= 0;
isMinSunOS5_5 = compareVersions(RegExp["$1"], "5.5") >= 0;
}
}
以上就是js事件處理，希望能給大家一個(gè)參考