????11) ???????

???????????

??????iOS??????????????ж????????????????????????????????????????CALayer?? CoreGraphics?? ??????OpenGL??????????????????

???????????Щ?????????????????????????????????????????????????????????￡?????iOS????ε??????????Andy Matuschak(???????????UIKitС??????)????????μ??????У????????????????????????з????????????

????????????????????????????????iOS?в??????????????????????????κ????????л???(?????????????!)??????????????????????????е????????????bundle?У???????????????С??????????????????????????ó???????????“???”??????——iOS??????????á???????????????(???簴?)??????????????????

?????????????????????????????????????????????????????????????????????????????????????????????????С???????????????????????????????????????????????????????????????????????(??????????????)??????????????м???????????????????????bundle???С??

???????????????????????????????????????????????????С??????????????????????????????У???????????????

????12) ??????澯??

?????????????????iOS?????????????е???????????????н???????δ??????澯?棺

????If your app receives this warning?? it must free up as much memory as possible. The best way to do this is to remove strong references to caches?? image objects?? and other data objects that can be recreated later.

???????????????????澯?棬??????б??????????檔?????????????????漰??????棬???????????????????????????????????′????????????

????UIKit??????????????????????????(low-memory)???棺

???????app delegate?е?applicationDidReceiveMemoryWarning: ??????

??????UIViewController????????д(Override)didReceiveMemoryWarning??????

???????????????????UIApplicationDidReceiveMemoryWarningNotificatio????

???????????????????????????????????κβ????????檔

???????磬UIViewController????????????????????????view;??UIViewController???????У?????????Щ???????????????в???????????????е????????release???

?????????????澯??????????????????????????????????е?????п??????????

?????????????????????????￡??????????????????????????????????????????????????????iOS??????е??????澯?湦????????в???!

13) ??????????????

??????Щ??????????????——????NSDateFormatter??NSCalendar??????????????????????Щ?????????????JSON/XML?е????????

???????????Щ?????????????????????????????????????????Щ????——??????????????????????????????????

????????????t????????????????????????е????????????????????

????????????????????????????????????????????ε???????????????????μ??????????????????????????????????????????

????// in your .h or inside a class extension@property (nonatomic?? strong) NSDateFormatter *formatter; // inside the implementation (.m)// When you need?? just use self.formatter- (NSDateFormatter *)formatter { if (! _formatter) { _formatter = [[NSDateFormatter alloc] init]; _formatter.dateFormat = @"EEE MMM dd HH:mm:ss Z yyyy"; // twitter date format } return _formatter;}

??????????????????????????NSDateFormatter?????????????????????μ????NSDateFormatter?????????????!??????????????????????????????????????NSDateFormatter????????????????