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

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;
}

其他回答

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;

}());

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。

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 );
}

这种检测IE的方法结合了jKey使用条件注释的答案和Owen使用用户代理的答案的优点,并避免了它们的缺点。

jKey's approach works up to version 9 and immune to user agent spoofing in IE 8 & 9. Owen's approach can fail on IE 5 & 6 (reporting 7) and is susceptible to UA spoofing, but it can detect IE versions >= 10 (now also including 12, which postdates Owen's answer). // ---------------------------------------------------------- // A short snippet for detecting versions of IE // ---------------------------------------------------------- // If you're not in IE (or IE version is less than 5) then: // ie === undefined // Thus, to detect IE: // if (ie) {} // And to detect the version: // ie === 6 // IE6 // ie > 7 // IE8, IE9 ... // ---------------------------------------------------------- var ie = (function(){ var v = 3, div = document.createElement('div'), all = div.getElementsByTagName('i'); while ( div.innerHTML = '<!--[if gt IE ' + (++v) + ']><i></i><![endif]-->', all[0] ); if (v <= 4) { // Check for IE>9 using user agent var match = navigator.userAgent.match(/(?:MSIE |Trident\/.*; rv:|Edge\/)(\d+)/); v = match ? parseInt(match[1]) : undefined; } return v; }());

这可以用来为包含IE版本的文档设置有用的类:

    if (ie) {
        document.documentElement.className += ' ie' + ie;
        if (ie < 9)
            document.documentElement.className += ' ieLT9';
    }

注意,如果IE处于兼容模式,它会检测正在使用的兼容模式。还要注意的是,IE版本主要适用于旧版本(<10);更高的版本更符合标准,使用modernizr.js之类的东西检查功能可能会更好。

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
}