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?


当前回答

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))
{

}

其他回答

简单的解决方案,停止思考浏览器和使用年。

var year = eval(today.getYear());
if(year < 1900 )
 {alert('Good to go: All browsers and IE 9 & >');}
else
 {alert('Get with it and upgrade your IE to 9 or >');}

我建议不要再重写这段代码了。我建议你使用Conditionizr库(http://conditionizr.com/),它能够测试特定的IE版本以及其他浏览器、操作系统,甚至是否有视网膜显示。

只包含您需要的特定测试的代码,您还可以获得经过多次迭代的测试库的好处(并且很容易升级而不会破坏您的代码)。

它还可以很好地与Modernizr配合,Modernizr可以处理所有情况,在这些情况下,您最好测试特定的功能,而不是特定的浏览器。

这是我喜欢的做法。它提供了最大限度的控制。(注意:条件语句仅在IE5 - 9中支持。)

首先正确地设置ie类

<!DOCTYPE html>
<!--[if lt IE 7]> <html class="lt-ie9 lt-ie8 lt-ie7"> <![endif]-->
<!--[if IE 7]>    <html class="lt-ie9 lt-ie8"> <![endif]-->
<!--[if IE 8]>    <html class="lt-ie9"> <![endif]-->
<!--[if gt IE 8]><!--> <html> <!--<![endif]-->    
<head>

然后你可以使用CSS来创建样式异常,或者,如果你需要,你可以添加一些简单的JavaScript:

(function ($) {
    "use strict";

    // Detecting IE
    var oldIE;
    if ($('html').is('.lt-ie7, .lt-ie8, .lt-ie9')) {
        oldIE = true;
    }

    if (oldIE) {
        // Here's your JS for IE..
    } else {
        // ..And here's the full-fat code for everyone else
    }

}(jQuery));

感谢Paul Irish。

使用特征检测来检测IE版本(IE6+,在IE6之前的浏览器被检测为6,非IE浏览器返回null):

var ie = (function (){
    if (window.ActiveXObject === undefined) return null; //Not IE
    if (!window.XMLHttpRequest) return 6;
    if (!document.querySelector) return 7;
    if (!document.addEventListener) return 8;
    if (!window.atob) return 9;
    if (!document.__proto__) return 10;
    return 11;
})();

编辑:为了方便起见,我创建了一个bower/npm repo: ie-version

更新:

更紧凑的版本可以写成一行:

return window.ActiveXObject === undefined ? null : !window.XMLHttpRequest ? 6 : !document.querySelector ? 7 : !document.addEventListener ? 8 : !window.atob ? 9 : !document.__proto__ ? 10 : 11;

你的代码可以做检查,但正如你所认为的,如果有人试图使用IE v1或> v19访问你的页面将不会得到错误,所以可能更安全的做检查的Regex表达式如下代码:

var userAgent = navigator.userAgent.toLowerCase();
// Test if the browser is IE and check the version number is lower than 9
if (/msie/.test(userAgent) && 
    parseFloat((userAgent.match(/.*(?:rv|ie)[\/: ](.+?)([ \);]|$)/) || [])[1]) < 9) {
  // Navigate to error page
}