differences between uiwebview and mobile safari [c

问题:

Have looked far and wide for info and have found no definitive list. Please add your observations. I'm sure it will come in handy to all.

回答1:

It doesn't have the Nitro Javascript engine. This makes executing Javascript much slower in UIWebView compared to Safari.

http://www.tuaw.com/2011/03/18/apple-confirms-some-webkit-optimizations-unavailable-to-ios-apps/

http://ariya.ofilabs.com/2012/06/nitro-javascriptcore-and-jit.html

回答2:

One thing I found, to my temporary sorrow is that UIWebView is a bit more strict while setting style values through JS. So say in mobile safari

element.style.width = 300; 

will work just fine, but in UIWebView you must set the value as

element.style.width = 300 + "px";

There are other differences which I'm discovering slowly. I'll update this as I do.

回答3:

When UIWebView scrolls its content, it freeze all JavaScript events until the end of scroll. So you absolutely can not programmatically observe and/or control the scrolling process like this common way:

window.onscroll = function() {
    var scrolled = window.pageYOffset || document.documentElement.scrollTop;
    // do something
}

because variable 'scrolled' will be updated only once - after the scroll is completely finished.

回答4:

You can set the initial max size for HTML5 SQL in Mobile Safari to 50MB, but UIWebView seems to be limited to 5MB. It refuses anything higher.

回答5:

Two obvious ones I have come across are authentication and pages with frames.

For authentication, UIWebView does not handle authentication challenges automatically, it's up to the developers to handle them.

For pages with framesets, UIWebView does not keep track of the browsing history for page transitinos within frames, which may be a desirable feature. It needs a bit of fiddling to accomplish this.

回答6:

When it comes to performance this is the best summary you are likely to find: http://www.guypo.com/mobile/ios-browsers-speed-bakeoff/

回答7:

The main differences are the address/search bar attached to the top of the page and the User Agent.

(note: there are plenty of others, but these are the few that usually matter)