当在object c中使用回调涵数时出现这样的警告：“capturing 'self' strongly in this block is likely to lead to a retain cycle”

我是从这里看的：http://stackoverflow.com/questions/14556605/capturing-self-strongly-in-this-block-is-likely-to-lead-to-a-retain-cycle

The capture of self here is coming in with your implicit property access of self.timerDisp - you can't refer to self or properties on self from within a block that will be strongly retained by self.

You can get around this by creating a weak reference to self before accessing timerDisp inside your block:

_weak typeof(self) weakSelf = self;[player addPeriodicTimeObserverForInterval:CMTimeMakeWithSeconds(0.1,100)queue:nil
                                usingBlock:^(CMTime time){
                                                current+=1;if(current==60){
                                                    min+=(current/60);
                                                    current =0;}[weakSelf.timerDisp setText:[NSString stringWithFormat:@"%02d:%02d",min,current]];}];