摘要：
Multi-tasking prevents apps from freezing. In most programming languages, achieving this is a bit tricky, but the NSOperationQueue class in iOS makes ... 阅读全文
摘要：
TheNSOperationQueueclass regulates the execution of a set ofNSOperationobjects. After being added to a queue, an operation remains in that queue until... 阅读全文
摘要：
Update 10/7/14: This tutorial has now been updated for iOS 8 and Swift;check it out!Everyone has had the frustrating experience of tapping a button or... 阅读全文