_cmd的詳細用法

_cmd在Objective-C的方法中表示當前方法的selector，正如同self表示當前方法調用的對象實例。

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//比如需要打印當前被調用的方法，可以在一個方法中添加： NSLog(@"%@ call",NSStringFromSelector(_cmd)); //會輸出類似 //2013-01-10 11:25:46.902 TDDataViewer[855:303] applicationDidFinishLaunching: call //這樣的內容。   //在cocos2d中，_cmd通常用於定時調用某個函數（schedule） //比如下面方法利用_cmd能夠不定時地調用某個函數 -(void) scheduleUpdates {     // schedule the first update as usual     [self schedule:@selector(irregularUpdate:) interval:1]; } -(void) irregularUpdate:(ccTime)delta {     // unschedule the method first [self unschedule:_cmd];     // I assume you’d have some kind of logic other than random to determine     // the next time the method should be called     float nextUpdate = CCRANDOM_0_1() * 10;     // then re-schedule it with the new interval using _cmd as the selector     [self schedule:_cmd interval:nextUpdate]; }