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?
我意识到我在这里有点晚了，但我一直在检查一个简单的一行方式来提供关于浏览器是否是IE以及从10个版本开始是哪个版本的反馈。我还没有为版本11编写代码，因此可能需要对此进行一些修改。
然而，这是代码，它作为一个对象，具有一个属性和一个方法，并依赖于对象检测，而不是抓取导航器对象(这是巨大的缺陷，因为它可以被欺骗)。
var isIE = { browser:/*@cc_on!@*/false, detectedVersion: function () { return (typeof window.atob !== "undefined") ? 10 : (typeof document.addEventListener !== "undefined") ? 9 : (typeof document.querySelector !== "undefined") ? 8 : (typeof window.XMLHttpRequest !== "undefined") ? 7 : (typeof document.compatMode !== "undefined") ? 6 : 5; } };
The usage is isIE.browser a property that returns a boolean and relies on conditional comments the method isIE.detectedVersion() which returns a number between 5 and 10. I am making the assumption that anything lower than 6 and you are in serious old school territory and you will something more beefy than a one liner and anything higher than 10 and you are in to newer territory. I have read something about IE11 not supporting conditional comments but I've not fully investigated, that is maybe for a later date.
无论如何，就像它一样，对于一行程序，它将涵盖IE浏览器和版本检测的基础知识。它远非完美，但它很小，很容易修改。
仅供参考，如果有人对如何实际实现这一点有任何疑问，那么下面的条件应该会有所帮助。
var isIE = { browser:/*@cc_on!@*/false, detectedVersion: function () { return (typeof window.atob !== "undefined") ? 10 : (typeof document.addEventListener !== "undefined") ? 9 : (typeof document.querySelector !== "undefined") ? 8 : (typeof window.XMLHttpRequest !== "undefined") ? 7 : (typeof document.compatMode !== "undefined") ? 6 : 5; } };
/* testing IE */
if (isIE.browser) {
alert("This is an IE browser, with a detected version of : " + isIE.detectedVersion());
}
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。
