在ARC中將自己分配給__weak時應用程序崩潰了嗎？

Question

我們在同一個名為“MyViewController”的ViewController中

即使它崩潰也很難再現，但我們從崩潰中得到了這個崩潰......

- (void)dismiss {


MyViewController* __weak weakSelf = self;---->//Crashing here

[UIView animateWithDuration:0.25 animations:^{
    MyViewController* __strong strongSelf = weakSelf;

    if (strongSelf) {
        CGRect backFrame = strongSelf.shroud.frame;
        strongSelf.shroud.backgroundImageView.frame = backFrame;
        strongSelf.shroud.shadedOverlay.backgroundColor = [UIColor colorWithWhite:0 alpha:0];

        CGRect semiViewFrame = CGRectMake(0, strongSelf.view.frame.size.height, strongSelf.shroud.contentView.frame.size.width, strongSelf.shroud.contentView.frame.size.height);
        strongSelf.shroud.contentView.frame = semiViewFrame;
    }

} 
completion:^(BOOL finished){
    MyViewController* __strong strongSelf = weakSelf;

    if (strongSelf) {
        [strongSelf.shroud removeFromSuperview];
        strongSelf.shroud = nil;
        strongSelf.semiViewController = nil;
    }
}];}

我們從crashlytics獲取以下崩潰日志：

    Thread : Crashed: com.apple.main-thread
    0  libobjc.A.dylib                0x39d148f8 _objc_trap() + 18446744073709552000
    1  libobjc.A.dylib                0x39d1495d _objc_inform
    2  libobjc.A.dylib                0x39d233cb weak_register_no_lock + 182
    3  libobjc.A.dylib                0x39d236ff objc_storeWeak + 110
    4  applicationName                       0x000e8071 -[MyViewController                 dismiss] (MyViewController:144)
    5  UIKit                          0x31f357f9 _UIGestureRecognizerSendActions + 196
    6  UIKit                          0x31de0a93 -[UIGestureRecognizer         _updateGestureWithEvent:buttonEvent:] + 1138
    7  UIKit                          0x321880bf ___UIGestureRecognizerUpdate_block_invoke + 46
    8  UIKit                          0x31da794f _UIGestureRecognizerRemoveObjectsFromArrayAndApplyBlocks + 218
    9  UIKit                          0x31da60b3 _UIGestureRecognizerUpdate + 298
    10 UIKit                          0x31ddf305 -[UIWindow _sendGesturesForEvent:] + 772
    11 UIKit                          0x31ddec2b -[UIWindow sendEvent:] + 666
    12 UIKit                          0x31db3e55 -[UIApplication sendEvent:] + 196
    13 UIKit                          0x31db2521 _UIApplicationHandleEventQueue + 7120
    14 CoreFoundation                 0x2f548faf __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 14
    15 CoreFoundation                 0x2f548477 __CFRunLoopDoSources0 + 206
    16 CoreFoundation                 0x2f546c67 __CFRunLoopRun + 630
    17 CoreFoundation                 0x2f4b1729 CFRunLoopRunSpecific + 524
    18 CoreFoundation                 0x2f4b150b CFRunLoopRunInMode + 106
    19 GraphicsServices               0x344106d3 GSEventRunModal + 138
    20 UIKit                          0x31e12871 UIApplicationMain + 1136

請幫我解決這個問題....

提前致謝

Answer 1

你不需要在這里做強/弱舞，因為沒有保留周期。 該塊具有對該視圖的強引用，但該視圖沒有對該塊的強引用。 動畫結束后，塊會釋放視圖。

Answer 2

Nanda請改變你的代碼

MyViewController* __strong weakSelf = self;

通過使這個弱，你試圖訪問weakSelf，而不是內存，你正在崩潰。