摘要：
官方：https://developer.apple.com/library/ios/documentation/General/Conceptual/CocoaTouch64BitGuide/Introduction/Introduction.htmlhttps://developer.apple.com/library/ios/documentation/General/Conceptual/CocoaTouch64BitGuide/OptimizingMemoryPerformance/OptimizingMemoryPerformance.html#//apple_ref/doc/ui 阅读全文
