在这个块中自我捕获可能导致保持循环 [英] capturing self strongly in this block is likely to lead to a retain cycle

问题描述

如何在xcode中避免此警告。这里是代码片段：

How can I avoid this warning in xcode. Here is the code snippet:

[player(AVPlayer object) addPeriodicTimeObserverForInterval:CMTimeMakeWithSeconds(0.1, 100)
queue:nil usingBlock:^(CMTime time) {
    current+=1;

    if(current==60)
    {
        min+=(current/60);
        current = 0;
    }

    [timerDisp(UILabel) setText:[NSString stringWithFormat:@"%02d:%02d",min,current]];///warning occurs in this line
}];

推荐答案

self 这里是你的隐式属性访问 self.timerDisp - 你不能引用 self 或属性 self 从 self 强烈保留的块内。

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.

你可以在访问 timerDisp self > in your block：

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]];
                                            }];

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