_cmd的详细用法

_cmd在Objective-C的方法中表示当前方法的selector，正如同self表示当前方法调用的对象实例。

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//比如需要打印当前被调用的方法，可以在一个方法中添加： NSLog(@"%@ call",NSStringFromSelector(_cmd)); //会输出类似 //2013-01-10 11:25:46.902 TDDataViewer[855:303] applicationDidFinishLaunching: call //这样的内容。   //在cocos2d中，_cmd通常用于定时调用某个函数（schedule） //比如下面方法利用_cmd能够不定时地调用某个函数 -(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]; }