javascript事件处理模型实例说明

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事件(Event)是JavaScript应用跳动的心脏 ,也是把所有东西粘在一起的胶水。当我们与浏览器中 Web 页面进行某些类型的交互时,事件就发生了。事件可能是用户在某些内容上的点击、鼠标经过某个特定元素或按下键盘上的某些按键。事件还可能是 Web 浏览器中发生的事情,比如说某个 Web 页面加载完成,或者是用户滚动窗口或改变窗口大小。

通过使用 JavaScript ,你可以监听特定事件的发生,并规定让某些事件发生以对这些事件做出响应。

一、添加事件监听

IE:

代码如下:
添加 detachEvent("onclick",function(){...}) //删除

FF:

代码如下:
添加多个事件监听,跟默认的对象事件不同 removeEventListenner("click",false)

二、得到事件对象

IE:

代码如下:
属性 }

FF:

代码如下:

通用:

代码如下:

//即时得到了通用的,但是他们返回对象的属性方法也不尽一致,但可以使用通过EventUtil来解决

/
格式化事件,因为IE和其他浏览器下获取事件的方式不同并且事件的属性也不尽相同,通过此方法提供一个一致的事件
/
EventUtil.formatEvent = function (oEvent) {
//isIE和isWin引用到一个js文件,判断浏览器和操作系统类型
if (isIE && isWin) {
oEvent.charCode = (oEvent.type == "keypress") ? oEvent.keyCode : 0;
//IE只支持冒泡,不支持捕获
oEvent.eventPhase = 2;
oEvent.isChar = (oEvent.charCode > 0);
oEvent.pageX = oEvent.clientX + document.body.scrollLeft;
oEvent.pageY = oEvent.clientY + document.body.scrollTop;
//阻止事件的默认行为
oEvent.preventDefault = function () {
this.returnValue = false;
};

  //将toElement,fromElement转化为标准的relatedTarget
 if (oEvent.type == "mou<a href="https://www.jb51.cc/tag/SEO/" title="SEO">SEO</a>ut") {
   oEvent.relatedTarget = oEvent.toElement;
 } else if (oEvent.type == "mou<a href="https://www.jb51.cc/tag/SEO/" title="SEO">SEO</a>ver") {
   oEvent.relatedTarget = oEvent.fromElement;
 }
 //取消冒泡   
 oEvent.stopPropagation = function () {
   this.cancelBubble = true;
 };

 oEvent.target = oEvent.srcElement;
 //<a href="https://www.jb51.cc/tag/tianjia/" target="_blank" class="keywords">添加</a>事件发生时间<a href="https://www.jb51.cc/tag/shuxing/" target="_blank" class="keywords">属性</a>,IE没有
 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];
}
};

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事件处理,希望能给大家一个参考,也希望大家多多支持编程之家。

原文链接:https://www.f2er.com/js/48290.html

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