检测浏览器的方式
1、对象特征检测法：判断浏览器能力的通用方法。如果更关注浏览器的能力而不在乎它的实际身份，就可以使用这种检测方法。常见的原生Ajax写法中就用这种方法来创建XMLHttpRequest：
IXHR: function(){ if(window.ActiveXObject){ XHR=new ActiveXObject('Microsoft.XMLHTTP'); }else if(window.XMLHttpRequest){ XHR=new XMLHttpRequest(); }else{ return null; } }
2、user-agent字符串检测法：通过能浏览器的user-agent字符串进行解析来判断，判断方法在下文的detect.js中
检测平台/操作系统
通过navigator折platform属性和user-agent字符串来判断，判断方法在下文的detect.js中
检测浏览器和操作系统-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; } }
