iOS SIGSEGV SEGV_ACCERR崩潰layoutSubviews

我的應用程序有時會在layoutSubview方法中崩潰。它發生在應用程序計算UITableViewCell的高度時。有時應用程序崩潰，並不總是。這裏的功能代碼：iOS SIGSEGV SEGV_ACCERR崩潰layoutSubviews

+ (CGFloat)heightForEditorialCommentData:(EditorialCommentVMData *)editorialData 
{ 
    EditorialCommentCell * cell = [EditorialCommentCell instanceCell]; 
    [cell applyViewModelData:editorialData]; 
    [cell layoutSubviews]; 
    return cell.commentTextLabel.frameBottom + kTextInsets.bottom; 
} 

+ (EditorialCommentCell *)instanceCell { 
    static EditorialCommentCell *instance = nil; 

    static dispatch_once_t onceToken; 
    dispatch_once(&onceToken, ^{ 
     NSArray *views = [[NSBundle mainBundle] loadNibNamed: @"EditorialCommentCell" owner:0 options:0]; 
     instance = views[0]; 
     instance.frame = CGRectMake(instance.contentView.frame.origin.x, 
             instance.contentView.frame.origin.y, 
             [[UIScreen mainScreen] bounds].size.width, 
             instance.contentView.frame.size.height); 
    }); 

    return instance; 
}

下面是堆棧跟蹤：

Thread : Crashed: com.apple.root.default-qos 
0 UIKit       0x2ff92b3a -[_UIViewAdditiveAnimationAction runActionForKey:object:arguments:] + 569 
1 UIKit       0x2ff92cf5 __67-[_UIViewAdditiveAnimationAction runActionForKey:object:arguments:]_block_invoke + 408 
2 QuartzCore      0x2f71e4c5 CA::Layer::end_change(CA::Transaction*, unsigned int, objc_object*) + 96 
3 QuartzCore      0x2f71f06b CA::Layer::set_bounds(CA::Rect const&, bool) + 530 
4 QuartzCore      0x2f71ed87 -[CALayer setBounds:] + 110 
5 UIKit       0x3017f84f -[_UILabelLayer setBounds:] + 58 
6 QuartzCore      0x2f71fe01 -[CALayer setFrame:] + 600 
7 UIKit       0x3017f7eb -[_UILabelLayer setFrame:] + 58 
8 UIKit       0x2fcfc4d7 -[UIView(Geometry) setFrame:] + 254 
9 UIKit       0x2fd09f53 -[UILabel setFrame:] + 138 
CRASH->10 MYAPP      0x000fb611 -[UIView(Frame) setFrameWidth:] (UIView+Frame.m:103) 
11 MYAPP      0x00130c75 -[EditorialCommentCell layoutSubviews] (EditorialCommentCell.m:139) 
12 MYAPP      0x001324ed +[EditorialCommentCell heightForEditorialCommentData:] (EditorialCommentCell.m:351) 
13 MYAPP      0x00115733 -[EditorialCommentsViewModel applyDataFromItem:toVMItem:] (EditorialCommentsViewModel.m:298) 
14 MYAPP      0x00114e73 -[EditorialCommentsViewModel vmDataFromItem:] (EditorialCommentsViewModel.m:222) 
15 MYAPP      0x000fac29 -[FatherViewModel insertItemsUpdatingExisting:intoVMItems:] (FatherViewModel.m:418) 
16 MYAPP      0x000f9cfd __39-[FatherViewModel updateItems:failure:]_block_invoke_3 (FatherViewModel.m:281) 
17 libdispatch.dylib    0x3a4718cb _dispatch_call_block_and_release + 10 
18 libdispatch.dylib    0x3a47ada3 _dispatch_root_queue_drain + 834 
19 libdispatch.dylib    0x3a47bcd7 _dispatch_worker_thread3 + 94 
20 libsystem_pthread.dylib  0x3a5d2e31 _pthread_wqthread + 668

這裏我layoutSubview代碼：

- (void)layoutSubviews { 
    [super layoutSubviews]; // Sometimes crashed here 

    CGFloat contentLeft = kTextInsets.left; 

    BOOL isReply = self.editorialCommentData.inReplyToCommentId != 0; 

    if (isReply) { 
     contentLeft += kAuthorLeftInset + self.authorImageView.frameWidth; 
    } 

    self.authorImageView.frameOrigin = CGPointMake(contentLeft, kContentInsets.top); 

    self.votesLabel.frameWidth = 200; // Sometimes crashed here 
    [self.votesLabel sizeToFit]; 

    self.votesLabel.frameTop = self.authorImageView.frameTop - 1.5f; 
    self.votesLabel.frameRight = self.contentView.bounds.size.width - kContentInsets.right; 

    <.....more code here.....> 
}

我認爲這是內存管理的問題。

來源

2014-10-09 ItsTipTop

我不知道它是否與你的問題有關，但是關於layoutSubviews方法，Apple文檔說「你不應該直接調用這個方法，如果你想強制佈局更新，改用setNeedsLayout方法在下一次更新圖紙之前這樣做。「 – 2014-10-09 08:27:21

@MarcoPace哦，謝謝，我現在就試試吧！ – ItsTipTop 2014-10-09 08:32:00

好的！我修好了它。從Marco關於layoutSubviews方法的評論：「你不應該直接調用這個方法。如果你想強制佈局更新，改用setNeedsLayout方法在下一次更新圖紙之前調用。」我只是改變layoutSubviews到layoutIfNeeded方法：

+ (CGFloat)heightForEditorialCommentData:(EditorialCommentVMData *)editorialData 
{ 
    EditorialCommentCell * cell = [EditorialCommentCell instanceCell]; 
    [cell applyViewModelData:editorialData]; 
    [cell layoutIfNeeded]; 
    return cell.commentTextLabel.frameBottom + kTextInsets.bottom; 
}

從蘋果文檔中關於layoutIfNeeded：

使用此方法強制子視圖的佈局圖前。使用接收該消息作爲根視圖的視圖，此方法將從根處開始的視圖子樹排除。

來源

2014-10-09 08:41:09 ItsTipTop

iOS SIGSEGV SEGV_ACCERR崩潰layoutSubviews

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