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

不要把这么简单的事情过分复杂化。只需使用一个简单的JScript条件注释。它是最快的,因为它不需要向非IE浏览器添加代码来进行检测,而且它的兼容性可以追溯到支持HTML条件注释之前的IE版本。简而言之,

var IE_version=(-1/*@cc_on,@_jscript_version@*/);

小心小注释:大多数(如果不是全部)会将特殊条件注释误认为常规注释,并将其删除

基本上,上面的代码将IE_version的值设置为您正在使用的IE版本,或者-1(如果您没有使用IE)。现场演示:

var IE_version = (1 / * @cc_on @_jscript_version@ * /); 如果(IE_version ! = = 1) { 文档。write("<h1>You are using Internet Explorer " + IE_version + "</h1>"); }其他{ 文档。write("<h1>您没有使用低于11的Internet Explorer版本</h1>"); }

这是基于条件注释只在旧版本的Internet Explorer中可见这一事实,而IE将@_jscript_version设置为浏览器的版本。例如,如果你使用Internet Explorer 7,那么@_jscript_version将被设置为7,因此,将执行的后处理javascript实际上是这样的:

var IE_version=(-1,7);

结果是7。

其他回答

使用条件注释。您正在尝试检测IE < 9的用户,条件注释将在这些浏览器中工作;在其他浏览器(IE >= 10和非IE)中,注释将被视为正常的HTML注释,这就是它们的本质。

示例HTML:

<!--[if lt IE 9]>
WE DON'T LIKE YOUR BROWSER
<![endif]-->

如果你需要,你也可以用脚本来完成:

var div = document.createElement("div");
div.innerHTML = "<!--[if lt IE 9]><i></i><![endif]-->";
var isIeLessThan9 = (div.getElementsByTagName("i").length == 1);
if (isIeLessThan9) {
    alert("WE DON'T LIKE YOUR BROWSER");
}

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
}

我喜欢这样:

<script>
   function isIE () {
       var myNav = navigator.userAgent.toLowerCase();
       return (myNav.indexOf('msie') != -1) ? parseInt(myNav.split('msie')[1]) : false;
   }    
   var ua = window.navigator.userAgent;
   //Internet Explorer | if | 9-11

   if (isIE () == 9) {
       alert("Shut down this junk! | IE 9");
   } else if (isIE () == 10){
       alert("Shut down this junk! | IE 10");
   } else if (ua.indexOf("Trident/7.0") > 0) {
       alert("Shut down this junk! | IE 11");
   }else{
       alert("Thank god it's not IE!");
   }

</script>

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))
{

}