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");
}

根据微软的说法,以下是最好的解决方案,它也很简单:

function getInternetExplorerVersion()
// Returns the version of Internet Explorer or a -1
// (indicating the use of another browser).
{
    var rv = -1; // Return value assumes failure.
    if (navigator.appName == 'Microsoft Internet Explorer')
    {
        var ua = navigator.userAgent;
        var re  = new RegExp("MSIE ([0-9]{1,}[\.0-9]{0,})");
        if (re.exec(ua) != null)
            rv = parseFloat( RegExp.$1 );
    }
    return rv;
}

function checkVersion()
{
    var msg = "You're not using Internet Explorer.";
    var ver = getInternetExplorerVersion();

    if ( ver > -1 )
    {
        if ( ver >= 8.0 ) 
            msg = "You're using a recent copy of Internet Explorer."
        else
            msg = "You should upgrade your copy of Internet Explorer.";
      }
    alert( msg );
}

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

function getIEVersion(){
     if (/MSIE |Trident\//.test( navigator.userAgent )=== false) return -1;
    /**[IE <=9]*/
    var isIE9L = typeof ( window.attachEvent ) === 'function' && !( Object.prototype.toString.call( window.opera ) == '[object Opera]' ) ? true : false;
    var re;
    if(isIE9L){
        re = new RegExp( "MSIE ([0-9]{1,}[\.0-9]{0,})" );
        if(re.exec( navigator.userAgent ) !== null)
            return parseFloat( RegExp.$1 );
        return -1;
    }
    /**[/IE <=9]*/
    /** [IE >= 10]*/
    if(navigator.userAgent.indexOf( 'Trident/' ) > -1){
        re = new RegExp( "rv:([0-9]{1,}[\.0-9]{0,})" );
        if(re.exec( navigator.userAgent ) !== null)
            return parseFloat( RegExp.$1 );
        return -1;
    }
    /**[/IE >= 10]*/
    return -1;
};

点击这里==>

var ieVersion = getIEVersion();

if(ieVersion < 0){
    //Not IE
}
//A version of IE

了解关于浏览器导航器的更多信息 https://developer.mozilla.org/en-US/docs/Web/API/Window/navigator

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。