通过javascript检测客户端环境
?
?? 通过javascript，判断客户端的环境，诸如使用的浏览器和操作系统。
?? user-agent字符串检测法是最原始的浏览器检测方式，每个访问网站的程序都必须提供一个user-agent字符来向服务器确定他的身份。
?? navigator对象包含一些浏览器信息，诸如名称、版本号和平台。
?
?? 以下这段代码是从“javascript 高级程序设计”抄出来的。可能有敲错的地方，具体没有测试，用的时候大概调试下哈。
//检测客户端环境var sUserAgent = navigator.userAgent;var fAppVersion = parseFloat(navigator.appVersion); //当前版本/***比较两个版本的新旧情况*参数：sVersion1,sVersion2 版本号，字符串*返回值：sVersion1比sVersion2 大，返回1*sVersion1比sVersion2 大，返回-1*sVersion1与sVersion2一样，返回0*/function compareVersions(sVersion1,sVersion2){var aVersion1 = sVersion1.split(".");var aVersion2 = sVersion2.split(".");//版本号位数不一样，在后面补0if(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;//判断是否是Opera浏览器var isMinOpera4 = isMinOpera5 = isMinOpera6 = isMinOpera7 = isMinOpera7_5 = false;//最低版本号if(isOpera){var fOperaVersion;//因为Opera会伪装成其他浏览器，所以通过两种方式检测if(navigator.appName == "Opera"){//没有伪装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 = isMinSafari_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"]);}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 = isMinIE7 = isMinIE8 = 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;isMinIE7 = fIEVersion >= 7;isMinIE8 = fIEVersion >= 8;}var isMoz = sUserAgent.indexOf("Gecko") > -1 && !isKHTML;var isMinMoz1 = isMinMoz1_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;}//以下是检测操作系统的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 = isWinVi = isWin7 = 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("Win NT 5.0") > -1 || sUserAgent.indexOf("Windows 2000") > -1;isWinXP = sUserAgent.indexOf("Win NT 5.1") > -1 || sUserAgent.indexOf("Windows XP") > -1;isWinVi = sUserAgent.indexOf("Windows NT 6.0") > -1 || sUserAgent.indexOf("Windows Vista") > -1;isWin7 = sUserAgent.indexOf("Windows NT 6.1") > -1 || sUserAgent.indexOf("Windows 7") > -1;isWinNT = sUserAgent.indexOf("WinNT") > -1 || sUserAgent.indexOf("Windows NT") > -1|| sUserAgent.indexOf("WinNT4.0") > -1 || sUserAgent.indexOf("Windows NT 4.0") > -1&& (!isWinME && !isWin2K && !isWinXP && !isWinVi && !isWin7);}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;}}