IOS如何解决强引用中的循环引用

一个对象中强引用了block，在block中又强引用了该对象，就会发射循环引用。

解决方法：

1、

__typeof (&*self) __weak weakSelf = self; [UIView animateWithDuration:_animationDuration animations:^{ CGRect frame = weakSelf.menuView.frame; frame.origin.y = -40 - _separatorHeight; weakSelf.menuWrapperView.frame = frame; } completion:nil];

2、

__weak CCBluetoothDevice * weakSelf = self; [weakSelf.OTATimer invalidate]; weakSelf.OTATimer = nil;

3、

id __block weakSelf = self;或

__weak id weakSelf = self;

4、将其中一方强制制空 xxx = nil。

 

另外：

__weak __typeof(self) weakSelf = self; dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^ { NSURL *portraitUrl = [NSURL URLWithString:strUrl]; __block UIImage *protraitImg = [UIImage imageWithData:[NSData dataWithContentsOfURL:portraitUrl]]; dispatch_sync(dispatch_get_main_queue(), ^{ __strong __typeof(weakSelf) strongSelf = weakSelf; if (protraitImg!=nil) { strongSelf.portraitImageView.image = protraitImg; } }); });

 

转载于:https://www.cnblogs.com/zhaosuning/p/9707805.html