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

使用条件注释检测JS中的IE

// ----------------------------------------------------------
// A short snippet for detecting versions of IE in JavaScript
// without resorting to user-agent sniffing
// ----------------------------------------------------------
// If you're not in IE (or IE version is less than 5) then:
//     ie === undefined
// If you're in IE (>=5) then you can determine which version:
//     ie === 7; // IE7
// Thus, to detect IE:
//     if (ie) {}
// And to detect the version:
//     ie === 6 // IE6
//     ie > 7 // IE8, IE9 ...
//     ie < 9 // Anything less than IE9
// ----------------------------------------------------------

// UPDATE: Now using Live NodeList idea from @jdalton

var ie = (function(){

    var undef,
        v = 3,
        div = document.createElement('div'),
        all = div.getElementsByTagName('i');

    while (
        div.innerHTML = '<!--[if gt IE ' + (++v) + ']><i></i><![endif]-->',
        all[0]
    );

    return v > 4 ? v : undef;

}());

其他回答

此函数将返回IE主版本号为整数,如果浏览器不是Internet Explorer,则未定义。像所有用户代理解决方案一样,这很容易受到用户代理欺骗(这是IE版本8以来的官方功能)。

function getIEVersion() {
    var match = navigator.userAgent.match(/(?:MSIE |Trident\/.*; rv:)(\d+)/);
    return match ? parseInt(match[1]) : undefined;
}

下面的代码依赖标识了所有情况下的IE版本(IE<=9, IE10, IE11和IE/Edge)

function detectIE() {
    var ua = window.navigator.userAgent;
    var msie = ua.indexOf('MSIE ');
    if (msie > 0) {
        // IE 10 or older => return version number
        return parseInt(ua.substring(msie + 5, ua.indexOf('.', msie)), 10);
    }
    var trident = ua.indexOf('Trident/');
    if (trident > 0) {
        // IE 11 => return version number
        var rv = ua.indexOf('rv:');
        return parseInt(ua.substring(rv + 3, ua.indexOf('.', rv)), 10);
    }
    var edge = ua.indexOf('Edge/');
    if (edge > 0) {
        // Edge (IE 12+) => return version number
        return parseInt(ua.substring(edge + 5, ua.indexOf('.', edge)), 10);
    }
    // other browser
    return false;
}

裁判:https://codepen.io/gapcode/pen/vEJNZN

我发现用于检查IE版本的最全面的JS脚本是http://www.pinlady.net/PluginDetect/IE/。整个图书馆在http://www.pinlady.net/PluginDetect/Browsers/。

在IE10中,不再支持条件语句。

在IE11中,用户代理不再包含MSIE。此外,使用用户代理是不可靠的,因为它可以被修改。

使用PluginDetect JS脚本,您可以检测IE,并通过使用针对特定IE版本的非常特定和精心制作的代码来检测准确的版本。当您非常关心您正在使用的浏览器版本时,这是非常有用的。

返回IE版本,否则返回false

function isIE () {
  var myNav = navigator.userAgent.toLowerCase();
  return (myNav.indexOf('msie') != -1) ? parseInt(myNav.split('msie')[1]) : false;
}

例子:

if (isIE () == 8) {
 // IE8 code
} else {
 // Other versions IE or not IE
}

or

if (isIE () && isIE () < 9) {
 // is IE version less than 9
} else {
 // is IE 9 and later or not IE
}

or

if (isIE()) {
 // is IE
} else {
 // Other browser
}

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))
{

}