self.contentView 里有时会出这样的子视图。。。。
<UILabel: 0x81667f0; frame = (0 0; 0 0); clipsToBounds = YES; userInteractionEnabled = NO; layer = <CALayer: 0x8166880>>
self.contentView 里有时会出这样的子视图。。。。
<UILabel: 0x81667f0; frame = (0 0; 0 0); clipsToBounds = YES; userInteractionEnabled = NO; layer = <CALayer: 0x8166880>>