JavaScript高階程式設計閱讀筆記（十六） javascript偵測瀏覽器和作業系統-detect.js_javascript技巧

偵測瀏覽器的方式

　　1、物件特徵偵測法：判斷瀏覽器能力的一般方法。如果更關注瀏覽器的能力而不在乎它的實際身份，就可以使用這種檢測方法。常見的原生Ajax寫法中就用這種方法來創建XMLHttpRequest：

複製代碼 代碼如下:

IXHR: function(){
if(window.ActiveXObject){
XHR=new ActiveXObject('Microsoft.XMLHTTP');
}else if(window.XMLHttpRequest){
=new XMLHttpRequest();
}else{
return null;
}
}

2、user-agent字串偵測法：透過能瀏覽器的user-agent字串進行解析來判斷，判斷方法在下文的detect.js中

檢測平台/作業系統

　　透過navigator摺platform屬性和user-agent字串來判斷，判斷方法在下文的detect.js中

檢測瀏覽器和操作系統-detect.js

複製代碼 程式碼如下:

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 aVersion2.push(" 0" ）；
}
} else if (aVersion1.length for (var i=0; i aVersion1.推（ 「0」）;
}
}

for (var i=0; i
if (aVersion1[i] 返回-1;
} else if (aVersion1[i] > aVersion2[i]) {
return 1;
}
}

回傳 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") > sUserAgent.indexOf("Konqueror") > -1
|| sUserAgent.indexOf("AppleWebKit") > 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("相容") > -1
&& sUserAgent.indexOf("MSIE") > -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)
&& (navigscape.Name ==== ")
&& (fAppVersion >= 4.0 && fAppVersion 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") > sUserAgent.indexOf("Windows XP") > -1;
isWinNT4 = sUserAgent.indexOf("WinNT") > -1
|| sUserAgent.indexOf("Windows NT") > 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") > 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;
}
}

作者：Artwl