正确的方法使用 Modernizr 来检测 IE？

小开

Modernizr doesn't detect browsers as such, it detects which feature and capability are present and this is the whole jist of what it's trying to do.

You could try hooking in a simple detection script like this and then using it to make your choice. I've included Version Detection as well just in case that's needed. If you only want to check of any version of IE you could just look for the navigator.userAgent having a value of "MSIE".

var BrowserDetect = {
init: function () {
this.browser = this.searchString(this.dataBrowser) || "Other";
this.version = this.searchVersion(navigator.userAgent) || this.searchVersion(navigator.appVersion) || "Unknown";
},
searchString: function (data) {
for (var i = 0; i < data.length; i++) {
var dataString = data[i].string;
this.versionSearchString = data[i].subString;


if (dataString.indexOf(data[i].subString) !== -1) {
return data[i].identity;
}
}
},
searchVersion: function (dataString) {
var index = dataString.indexOf(this.versionSearchString);
if (index === -1) {
return;
}


var rv = dataString.indexOf("rv:");
if (this.versionSearchString === "Trident" && rv !== -1) {
return parseFloat(dataString.substring(rv + 3));
} else {
return parseFloat(dataString.substring(index + this.versionSearchString.length + 1));
}
},


dataBrowser: [
{string: navigator.userAgent, subString: "Edge", identity: "MS Edge"},
{string: navigator.userAgent, subString: "MSIE", identity: "Explorer"},
{string: navigator.userAgent, subString: "Trident", identity: "Explorer"},
{string: navigator.userAgent, subString: "Firefox", identity: "Firefox"},
{string: navigator.userAgent, subString: "Opera", identity: "Opera"},
{string: navigator.userAgent, subString: "OPR", identity: "Opera"},


{string: navigator.userAgent, subString: "Chrome", identity: "Chrome"},
{string: navigator.userAgent, subString: "Safari", identity: "Safari"}
]
};
    

BrowserDetect.init();
document.write("You are using <b>" + BrowserDetect.browser + "</b> with version <b>" + BrowserDetect.version + "</b>");

You can then simply check for:

BrowserDetect.browser == 'Explorer';
BrowserDetect.version <= 9;

小开

You can use the < !-- [if IE] > hack to set a global js variable that then gets tested in your normal js code. A bit ugly but has worked well for me.

小开

Detecting CSS 3D transforms

Modernizr can detect CSS 3D transforms, yeah. The truthiness of Modernizr.csstransforms3d will tell you if the browser supports them.

The above link lets you select which tests to include in a Modernizr build, and the option you're looking for is available there.

Detecting IE specifically

Alternatively, as user356990 answered, you can use conditional comments if you're searching for IE and IE alone. Rather than creating a global variable, you can use HTML5 Boilerplate's <html> conditional comments trick to assign a class:

<!--[if lt IE 7]>      <html class="no-js lt-ie9 lt-ie8 lt-ie7"> <![endif]-->
<!--[if IE 7]>         <html class="no-js lt-ie9 lt-ie8"> <![endif]-->
<!--[if IE 8]>         <html class="no-js lt-ie9"> <![endif]-->
<!--[if gt IE 8]><!--> <html class="no-js"> <!--<![endif]-->

If you already have jQuery initialised, you can just check with $('html').hasClass('lt-ie9'). If you need to check which IE version you're in so you can conditionally load either jQuery 1.x or 2.x, you can do something like this:

myChecks.ltIE9 = (function(){
var htmlElemClasses = document.querySelector('html').className.split(' ');
if (!htmlElemClasses){return false;}
for (var i = 0; i < htmlElemClasses.length; i += 1 ){
var klass = htmlElemClasses[i];
if (klass === 'lt-ie9'){
return true;
}
}
return false;
}());

N.B. IE conditional comments are only supported up to IE9 inclusive. From IE10 onwards, Microsoft encourages using feature detection rather than browser detection.

Whichever method you choose, you'd then test with

if ( myChecks.ltIE9 || Modernizr.csstransforms3d ){
// iframe or flash fallback
}

Don't take that || literally, of course.

小开

If you're looking for a JS version (using a combination of feature detection and UA sniffing) of what html5 boilerplate used to do:

var IE = (!! window.ActiveXObject && +(/msie\s(\d+)/i.exec(navigator.userAgent)[1])) || NaN;
if (IE < 9) {
document.documentElement.className += ' lt-ie9' + ' ie' + IE;
}

小开

CSS tricks have a good solution to target IE 11:

http://css-tricks.com/ie-10-specific-styles/

The .NET and Trident/7.0 are unique to IE so can be used to detect IE version 11.

The code then adds the User Agent string to the html tag with the attribute 'data-useragent', so IE 11 can be targeted specifically...

小开

You can use Modernizr to detect simply IE or not IE, by checking for SVG SMIL animation support.

If you've included SMIL feature detection in your Modernizr setup, you can use a simple CSS approach, and target the .no-smil class that Modernizr applies to the html element:

html.no-smil {
/* IE/Edge specific styles go here - hide HTML5 content and show Flash content */
}

Alternatively, you could use Modernizr with a simple JavaScript approach, like so:

if ( Modernizr.smil ) {
/* set HTML5 content */
} else {
/* set IE/Edge/Flash content */
}

Bear in mind, IE/Edge might someday support SMIL, but there are currently no plans to do so.

For reference, here's a link to the SMIL compatibility chart at caniuse.com.

小开

I needed to detect IE vs most everything else and I didn't want to depend on the UA string. I found that using es6number with Modernizr did exactly what I wanted. I don't have much concern with this changing as I don't expect IE to ever support ES6 Number. So now I know the difference between any version of IE vs Edge/Chrome/Firefox/Opera/Safari.

More details here: http://caniuse.com/#feat=es6-number

Note that I'm not really concerned about Opera Mini false negatives. You might be.

小开

Well, after doing more research on this topic I ended up using following solution for targeting IE 10+. As IE10&11 are the only browsers which support the -ms-high-contrast media query, that is a good option without any JS:

@media screen and (-ms-high-contrast: active), screen and (-ms-high-contrast: none) {
/* IE10+ specific styles go here */
}

Works perfectly.

小开

最佳答案

I agree we should test for capabilities, but it's hard to find a simple answer to "what capabilities are supported by 'modern browsers' but not 'old browsers'?"

So I fired up a bunch of browsers and inspected Modernizer directly. I added a few capabilities I definitely require, and then I added "inputtypes.color" because that seems to cover all the major browsers I care about: Chrome, Firefox, Opera, Edge...and NOT IE11. Now I can gently suggest the user would be better off with Chrome/Opera/Firefox/Edge.

This is what I use - you can edit the list of things to test for your particular case. Returns false if any of the capabilities are missing.

/**
* Check browser capabilities.
*/
public CheckBrowser(): boolean
{
let tests = ["csstransforms3d", "canvas", "flexbox", "webgl", "inputtypes.color"];


// Lets see what each browser can do and compare...
//console.log("Modernizr", Modernizr);


for (let i = 0; i < tests.length; i++)
{
// if you don't test for nested properties then you can just use
// "if (!Modernizr[tests[i]])" instead
if (!ObjectUtils.GetProperty(Modernizr, tests[i]))
{
console.error("Browser Capability missing: " + tests[i]);
return false;
}
}


return true;
}

And here is that GetProperty method which is needed for "inputtypes.color".

/**
* Get a property value from the target object specified by name.
*
* The property name may be a nested property, e.g. "Contact.Address.Code".
*
* Returns undefined if a property is undefined (an existing property could be null).
* If the property exists and has the value undefined then good luck with that.
*/
public static GetProperty(target: any, propertyName: string): any
{
if (!(target && propertyName))
{
return undefined;
}


var o = target;


propertyName = propertyName.replace(/\[(\w+)\]/g, ".$1");
propertyName = propertyName.replace(/^\./, "");


var a = propertyName.split(".");


while (a.length)
{
var n = a.shift();


if (n in o)
{
o = o[n];


if (o == null)
{
return undefined;
}
}
else
{
return undefined;
}
}


return o;
}