【JavaScript】检测浏览器和操作系统
注：代码转自《Professional JavaScript™ for Web Developers》一书。
Web编程中，识别用户的浏览器以及操作系统非常重要。因为它们对HTML和JavaScript的支持程度有所不同。
一般应用在系统登陆页面或者首页中。
具体应用如下：
<html>
<head>
<title>Login</title>
<script type="text/javascript" src="detect.js"></script>
<script type="text/javascript">
window.onload = function () {
if ((isMinIE5_5 && isWin) || (isMinMoz1 && isUnix)
|| (isMinSafari1 && isMac)) {
document.getElementById("divLogin").style.visibility = "visible" ;
document.getElementById("divError").style.visibility = "hidden"
}
};
</script>
</head>
<body>
<form method="post" action="DoLogin.jsp">
<div style="border: 2px dashed blue; background-color: #dedede; height: 300px; padding: 10px">
<div id="divError" style="position: absolute; left: 20px; top: 100px; ">
This Web application requires one of the following:
<ul>
<li>Internet Explorer 5.5 or higher for Windows</li>
<li>Mozilla 1.0 or higher for Unix</li>
<li>Safari 1.0 or higher for Macintosh</li>
</ul>
<noscript>
<p>This Web application also requires JavaScript (if you are using one of the above browsers, make sure that JavaScript is enabled).</p>
</noscript>
</div>
<div id="divLogin" style="position: absolute; left: 20px; top: 100px; visibility: hidden">
<table border="0" width="100%" height="100%"><tr><td align="center">
<table border="0">
<tr>
<td>Username:</td><td><input type="text" name="txtUsername" /></td>
</tr>
<tr>
<td>Password:</td><td><input type="password" name="txtPassword" /></td>
</tr>
<tr>
<td> </td><td><input type="Submit" value="Login" /></td>
</tr>
</table>
</td></tr></table>
</div>
</div>
</form>
</body>
</html>
detect.js
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 ;
}
}
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