A.init->viewDidLoad->viewDidAppear->viewDidUnload B.init->viewDidAppear->viewDidLoad->viewDidUnload C.init->viewDidLoad->viewDidUnload->viewDidAppear D.init->viewDidAppear->viewDidUnload->viewDidLoad
下面代碼的作用是讓doSomeThing函數(shù)每隔1秒被調(diào)用1次。請(qǐng)問(wèn)哪里有問(wèn)題()
A.沒(méi)有將timer加入runloop B.doSomeThing缺少參數(shù) C.忘記傳遞數(shù)據(jù)給userInfo D.myTimer對(duì)象未通過(guò)[[myTimeralloc] init]方法初始化
A.GCD所用的開(kāi)銷要比NSThread大 B.可以在子線程中修改UI元素 C.NSOperationQueue是比NSthread更高層的封裝 D.GCD可以根據(jù)不同優(yōu)先級(jí)分配線程