iphone – 如何在self.view的属性上设置一个lldb观察点？
发布时间：2020-12-15 01:57:30 所属栏目：百科 来源：网络整理
导读：我想跟踪什么时候改变self.view的大
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我想跟踪什么时候改变self.view的大小。什么是正确的格式？
(lldb) po self.view (UIView *) $1 = 0x0a8aba20 <UIView: 0xa8aba20; frame = (0 0; 480 864); autoresize = W+TM+BM; layer = <CALayer: 0xa8aba50>> (lldb) watch set variable self.view.frame.size.width error: "self" is a pointer and . was used to attempt to access "view". Did you mean "self->view.frame.size.width"? (lldb) watch set variable self->view error: "view" is not a member of "(PlayViewController *) self" (lldb) watch set variable self->view.frame.size.width error: "view" is not a member of "(PlayViewController *) self" 我已经尝试了文档和其他lldb观察点问题，但是在这种具体情况下找不到任何东西。 谢谢你的帮助。 解决方法
视图控制器从其_view实例变量引用其视图。
视图不直接存储其框架。它只返回其图层的“框架”。 该视图从其_layer实例变量引用其层。 该层也不存储框架。它从其边界，位置，锚点和变换计算其帧。大小是边界的一部分。 该层不直接在实例变量中存储其边界。相反，它的层实例变量引用私有C类的实例CA :: Layer。该类的成员布局是无证的。 换句话说，您可以进行自我> _view-> _layer->图层以获取CA :: Layer实例，但是因为您不知道CA :: Layer到找到界限。 所以，尝试使用观察点来检测视图大小的变化是相当困难的。 在[CALayer setBounds：]上放置一个断点是比较容易的。 在模拟器上 记住在断点条件下使用图层地址，而不是视图地址。 (lldb) po self.view (UIView *) $1 = 0x0a034690 <UIView: 0xa034690; frame = (0 20; 768 1004); autoresize = W+H; layer = <CALayer: 0xa034780>> (lldb) break set -F '-[CALayer setBounds:]' -c '((int*)$esp)[1] == 0xa034780' Breakpoint created: 2: name = '-[CALayer setBounds:]',locations = 1,resolved = 1 当断点被击中时，CALayer实例由((int *)$ esp)[1]引用，新的边界是*(CGRect *)($ esp 12)： (lldb) po ((int*)$esp)[1] (int) $8 = 167987072 <CALayer:0xa034780; position = CGPoint (384 480); bounds = CGRect (0 0; 768 1004); delegate = <UIView: 0xa034690; frame = (0 -22; 768 1004); autoresize = W+H; layer = <CALayer: 0xa034780>>; sublayers = (<CALayer: 0xa033010>); backgroundColor = <CGColor 0xa034960> [<CGColorSpace 0xa02b3b0> (kCGColorSpaceDeviceRGB)] ( 1 1 1 1 )> (lldb) p *(CGRect*)($esp+12) (CGRect) $9 = origin=(x=0,y=0) size=(width=768,height=960) (lldb) finish (lldb) po 0xa034780 (int) $10 = 167987072 <CALayer:0xa034780; position = CGPoint (384 480); bounds = CGRect (0 0; 768 960); delegate = <UIView: 0xa034690; frame = (0 0; 768 960); autoresize = W+H; layer = <CALayer: 0xa034780>>; sublayers = (<CALayer: 0xa033010>); backgroundColor = <CGColor 0xa034960> [<CGColorSpace 0xa02b3b0> (kCGColorSpaceDeviceRGB)] ( 1 1 1 1 )> 在设备上 记住在断点条件下使用图层地址，而不是视图地址。 (lldb) po self.view (UIView *) $0 = 0x1f031a10 <UIView: 0x1f031a10; frame = (0 20; 768 1004); autoresize = W+H; layer = <CALayer: 0x1f031b00>> (lldb) break set -F '-[CALayer setBounds:]' -c '$r0 == 0x1f031b00' Breakpoint created: 2: name = '-[CALayer setBounds:]',resolved = 1 当断点被击中时，CALayer实例由$ r0引用，新的X原点在$ r2中，新的Y原点在$ r3中，新的大小为*(CGSize *)$ sp： (lldb) po $r0 (unsigned int) $7 = 520297216 <CALayer:0x1f031b00; position = CGPoint (384 480); bounds = CGRect (0 0; 768 1004); delegate = <UIView: 0x1f031a10; frame = (0 -22; 768 1004); autoresize = W+H; layer = <CALayer: 0x1f031b00>>; sublayers = (<CALayer: 0x1f030840>); backgroundColor = <CGColor 0x1f031ce0> [<CGColorSpace 0x1e530ad0> (kCGColorSpaceDeviceRGB)] ( 1 1 1 1 )> (lldb) p/f $r2 (unsigned int) $14 = 0 (lldb) p/f $r3 (unsigned int) $15 = 0 (lldb) p *(CGSize *)$sp (CGSize) $16 = (width=768,height=960) (lldb) finish (lldb) po 0x1f031b00 (int) $17 = 520297216 <CALayer:0x1f031b00; position = CGPoint (384 480); bounds = CGRect (0 0; 768 960); delegate = <UIView: 0x1f031a10; frame = (0 0; 768 960); autoresize = W+H; layer = <CALayer: 0x1f031b00>>; sublayers = (<CALayer: 0x1f030840>); backgroundColor = <CGColor 0x1f031ce0> [<CGColorSpace 0x1e530ad0> (kCGColorSpaceDeviceRGB)] ( 1 1 1 1 )> （编辑：李大同） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |