WKWebView instances will ignore any of the default networking storages (NSURLCache, NSHTTPCookieStorage, NSCredentialStorage) and also the standard networking classes you can use to customize the network requests (NSURLProtocol, etc.).
So the cookies of the WKWebView instance are not stored in the standard Cookie storage of your App, and so NSURLSession/NSURLConnection which only uses the standard Cookie storage has no access to the cookies of WKWebView (and exactly this is probably the problem you have: the „login status“ is most likely stored in a cookie, but NSURLSession/NSURLConnection won’t see the cookie).
The same is the case for the cache, for the credentials etc. WKWebView has its own private storages and therefore does not play well with the standard Cocoa networking classes.
You also can’t customize the requests (add your own custom HTTP headers, modify existing headers, etc), use your own custom URL schemes etc, because also NSURLProtocol is not supported by WKWebView.
So right now WKWebView is pretty useless for many Apps, because it does not participate with the standard networking APIs of Cocoa.
I still hope that Apple will change this until iOS 8 gets released, because otherwise WKWebView will be useless for many Apps, and we are probably stick with UIWebView a little bit longer.
So send bug reports to Apple, so Apple gets to know that these issues are serious and needs to be fixed
NSURLCache和NSHTTPCookieStroage无法操作(WKWebView)WebCore进程的缓存和Cookie。
WKWebView实例将会忽略任何的默认网络存储器(NSURLCache, NSHTTPCookieStorage, NSCredentialStorage) 和一些标准的自定义网络请求类(NSURLProtocol,等等.)。
WKWebView实例不会把Cookie存入到App标准的的Cookie容器(NSHTTPCookieStorage)中,因为 NSURLSession/NSURLConnection等网络请求使用NSHTTPCookieStorage进行访问Cookie,所以不能访问WKWebView的Cookie，现象就是WKWebView存了Cookie，其他的网络类如NSURLSession/NSURLConnection却看不到。
与Cookie相同的情况就是WKWebView的缓存，凭据等。WKWebView都拥有自己的私有存储,因此和标准Cocoa网络类兼容的不是那么好。
你也不能自定义requests(增加自己的http header，更改已经存在的header)使用自定义的 URL schemes等等，因为NSURLProtocol也是不支持WKWebView的。
在用AFN进行网络请求,NSURLSession会使用NSHTTPCookieStorage进行访问Cookie,但是wkwebview并没有把cookie存放到NSHTTPCookieStorage中,也就是post/get请求中并不会带有cookie,导致server端cookie校验失败,重新生成cookie.看似登录其实并未登录.
那么,手动之.
页面退出时,由于NSHTTPCookieStorage中仍然存在cookie,需要手动清除
至此cookie,脱坑
stackoverflow.com/questions/24464397/how-can-i-retrieve-a-file-using-WKWebView