问题
This post is half question - half announcement.. i develop iOS applications which include UIWebView that performs javascript code. When i run the app on devices with the newly iOS 7, some of the functionality doesn't work. after long debugging, i have managed to isolate the reason. Javascript AJAX has a request API with the constructor method open :
XMLHttpRequest.open(method,url,async)
'asynch' argument is false if the call should be blocking and true otherwise. the problem on iOS 7 safari only is that this method throws exception if 'async' is false.
so, hope this would help to any of you encountering the same problem, and if anyone can shad a light about this bug or way to work around it it would be great
Thanks!
回答1:
The UIWebview does not allow synchronous XHRs in IOS7.
This is one of the frustrating differences between the WebView and Safari (which does allow them).
The workaround:
Create an Objective-C function that makes a synchronous HTTP request.
Call that function from JavaScript. (This happens synchronously.)
Of course, if you wanted any benefits like caching, you would have to implement that yourself.
It's a bit baffling why Apple would think requiring that workaround is a good idea.
来源：https://stackoverflow.com/questions/18965329/ios-7-javascript-xmlhttprequest-bug