viewController 各个life cycle阶段,view跟 subviews 的frame 状态分析

viewController 各个life cycle阶段,view和 subviews 的frame 状态分析


2013-03-27 17:04:40.605 testView[4685:c07] --- viewDidLoad.. ---

2013-03-27 17:04:40.608 testView[4685:c07] <UIView: 0x7553320; frame = (0 20; 320 460); autoresize = RM+BM; layer = <CALayer: 0x7553380>>

2013-03-27 17:04:40.609 testView[4685:c07] <UIScrollView: 0x7551890; frame = (0 0; 0 0); clipsToBounds = YES; autoresize = TM+BM; gestureRecognizers = <NSArray: 0x75528a0>; layer = <CALayer: 0x7551ab0>; contentOffset: {0, 0}>

2013-03-27 17:04:40.610 testView[4685:c07] <UIScrollView: 0x7551890; frame = (0 0; 0 0); clipsToBounds = YES; autoresize = TM+BM; gestureRecognizers = <NSArray: 0x75528a0>; layer = <CALayer: 0x7551ab0>; contentOffset: {0, 0}>

2013-03-27 17:04:40.613 testView[4685:c07] view bounds-origin: 0.00 0.00 size:320.00 460.00 

2013-03-27 17:04:40.614 testView[4685:c07] bounds-origin: 0.00 0.00 size:0.00 0.00 


viewDidLoad 的时候,self.view 和subview 的frame 未完成初始化,所以它们的frame 都是0,0,0,0

2013-03-27 17:04:40.615 testView[4685:c07] --- viewWillAppear.. ---

2013-03-27 17:16:18.755 testView[4745:c07] <UIView: 0x7557620; frame = (0 20; 320 460); autoresize = RM+BM; layer = <CALayer: 0x7557680>>

2013-03-27 17:16:18.756 testView[4745:c07] <UIScrollView: 0x7555b90; frame = (0 0; 0 0); clipsToBounds = YES; autoresize = TM+BM; gestureRecognizers = <NSArray: 0x7556ba0>; layer = <CALayer: 0x7555db0>; contentOffset: {0, 0}>


2013-03-27 17:04:40.618 testView[4685:c07] view bounds-origin: 0.00 0.00 size:320.00 460.00 

2013-03-27 17:04:40.620 testView[4685:c07] scrollview bounds-origin: 0.00 0.00 size:0.00 0.00 


viewWillAppear 的时候,self.view 保证完成初始化,但是subview 的frame 未完成初始化,所以view的frame size 是 size:320.00 460.00 ,但是subview 仍然是 0,0

2013-03-27 17:04:40.633 testView[4685:c07] --- viewDidAppear.. ---

2013-03-27 17:16:18.773 testView[4745:c07] <UIView: 0x7557620; frame = (0 20; 320 460); autoresize = RM+BM; layer = <CALayer: 0x7557680>>

2013-03-27 17:16:18.775 testView[4745:c07] <UIScrollView: 0x7555b90; frame = (0 0; 320 460); clipsToBounds = YES; autoresize = TM+BM; gestureRecognizers = <NSArray: 0x7556ba0>; layer = <CALayer: 0x7555db0>; contentOffset: {0, 0}>

2013-03-27 17:04:40.637 testView[4685:c07] view bounds-origin: 0.00 0.00 size:320.00 460.00 

2013-03-27 17:04:40.639 testView[4685:c07] scrollview bounds-origin: 0.00 0.00 size:320.00 460.00 


viewDidAppear 的时候,subview 也终于完成初始化


然后通过一个按钮,我让scrollview 的contentOffset 偏移了 (0,-50)
2013-03-27 17:04:48.304 testView[4685:c07] --- moved.. ---


2013-03-27 17:19:30.464 testView[4774:c07] --- moved.. ---

2013-03-27 17:19:30.465 testView[4774:c07] <UIView: 0x75b3d80; frame = (0 20; 320 460); autoresize = RM+BM; layer = <CALayer: 0x75b3de0>>

2013-03-27 17:19:30.465 testView[4774:c07] <UIScrollView: 0x75b22f0; frame = (0 0; 320 460); clipsToBounds = YES; autoresize = TM+BM; gestureRecognizers = <NSArray: 0x75b3300>; layer = <CALayer: 0x75b2510>; contentOffset: {0, -50}>

2013-03-27 17:19:30.467 testView[4774:c07] view bounds-origin: 0.00 0.00 size:320.00 460.00 

2013-03-27 17:19:30.468 testView[4774:c07] bounds-origin: 0.00 -50.00 size:320.00 460.00 

留意到偏移了之后,scrollview除了 contentOffset 改变了, bounds的坐标也一样改变。


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如果你尝试过,把某个view中的一个subview的坐标 改到负值,例如(-100,-50)
这样subview 的位置frame是超出了view 的bounds的。

这时候,假设subview其实是个Button,即便Button是可视的,肉眼可见,也是enable状态,你也按不到它。

似乎iOS上,超出bounds 范围的subview 是认为不可交互的。