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 頁面進(jìn)行某些類型的交互時(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)過某個(gè)特定元素或按下鍵盤上的某些按鍵。事件還可能是 Web 瀏覽器中發(fā)生的事情，比如說某個(gè) Web 頁面加載完成，或者是用戶滾動(dòng)窗口或改變窗口大小。

通過使用 JavaScript ，你可以監(jiān)聽特定事件的發(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

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，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){

    ....  //通過傳入?yún)?shù)來控制

}

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EventUtil來解決！

代碼如下:

var EventUtil = new Object;

/**//*

  此方法用來給特定對(duì)象添加事件，oTarget是指定對(duì)象,sEventType是事件類型，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;

   }

};

/*

  此方法用來移除特定對(duì)象的特定事件，oTarget是指定對(duì)象,sEventType是事件類型，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)類型的js文件，通過引入一些名字顯而易見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