如果我们网站的用户使用的是v9之前版本的Internet Explorer，我希望将他们弹出到一个错误页面。不值得我们花时间和金钱去支持iev9之前的版本。所有其他非ie浏览器的用户都没问题，不应该被弹出。以下是提议的代码:
if(navigator.appName.indexOf("Internet Explorer")!=-1){ //yeah, he's using IE
var badBrowser=(
navigator.appVersion.indexOf("MSIE 9")==-1 && //v9 is ok
navigator.appVersion.indexOf("MSIE 1")==-1 //v10, 11, 12, etc. is fine too
);
if(badBrowser){
// navigate to error page
}
}
这段代码能行吗?
为了阻止一些可能会出现在我面前的评论:
Yes, I know that users can forge their useragent string. I'm not concerned.
Yes, I know that programming pros prefer sniffing out feature-support instead of browser-type but I don't feel this approach makes sense in this case. I already know that all (relevant) non-IE browsers support the features that I need and that all pre-v9 IE browsers don't. Checking feature by feature throughout the site would be a waste.
Yes, I know that someone trying to access the site using IE v1 (or >= 20) wouldn't get 'badBrowser' set to true and the warning page wouldn't be displayed properly. That's a risk we're willing to take.
Yes, I know that Microsoft has "conditional comments" that can be used for precise browser version detection. IE no longer supports conditional comments as of IE 10, rendering this approach absolutely useless.
还有其他明显需要注意的问题吗?
如微软参考页所述，IE版本10不再支持条件注释。
var ieDetector = function() {
var browser = { // browser object
verIE: null,
docModeIE: null,
verIEtrue: null,
verIE_ua: null
},
tmp;
tmp = document.documentMode;
try {
document.documentMode = "";
} catch (e) {};
browser.isIE = typeof document.documentMode == "number" || eval("/*@cc_on!@*/!1");
try {
document.documentMode = tmp;
} catch (e) {};
// We only let IE run this code.
if (browser.isIE) {
browser.verIE_ua =
(/^(?:.*?[^a-zA-Z])??(?:MSIE|rv\s*\:)\s*(\d+\.?\d*)/i).test(navigator.userAgent || "") ?
parseFloat(RegExp.$1, 10) : null;
var e, verTrueFloat, x,
obj = document.createElement("div"),
CLASSID = [
"{45EA75A0-A269-11D1-B5BF-0000F8051515}", // Internet Explorer Help
"{3AF36230-A269-11D1-B5BF-0000F8051515}", // Offline Browsing Pack
"{89820200-ECBD-11CF-8B85-00AA005B4383}"
];
try {
obj.style.behavior = "url(#default#clientcaps)"
} catch (e) {};
for (x = 0; x < CLASSID.length; x++) {
try {
browser.verIEtrue = obj.getComponentVersion(CLASSID[x], "componentid").replace(/,/g, ".");
} catch (e) {};
if (browser.verIEtrue) break;
};
verTrueFloat = parseFloat(browser.verIEtrue || "0", 10);
browser.docModeIE = document.documentMode ||
((/back/i).test(document.compatMode || "") ? 5 : verTrueFloat) ||
browser.verIE_ua;
browser.verIE = verTrueFloat || browser.docModeIE;
};
return {
isIE: browser.isIE,
Version: browser.verIE
};
}();
document.write('isIE: ' + ieDetector.isIE + "<br />");
document.write('IE Version Number: ' + ieDetector.Version);
然后使用:
if((ieDetector.isIE) && (ieDetector.Version <= 9))
{
}
