Question

在自定义滚动视图上调用_subtreeDescription会显示：

Seohtracker devel [22556：303] [AF O WLU] h = - ＆amp; - v = - ＆amp; - EHGraph_scroll 0x100c52f20 f =（367,169,250,168）b =（ - ）=＆gt; _NSViewBackingLayer（0x101a77500）a = {0,0} p = {367,169} b =（0,0,250,168）superlayer = 0x101a756f0 TILED = no TIME drawRect：min / mean / max 0.00 / 0.00 / 0.00 ms

p和b似乎是从框架f派生的。参数a的含义是什么？

Answer 1

这是一个图层，事物的名称与视图略有不同。看看CALayer，这些意思很快就会变得清晰。

p = position
b = bounds
a = anchorPoint

此外，如果您直接在LLVM中打印支持层，您将获得有关该层当前属性的更详细的描述：

(lldb) po 0x6080000c5550
<SCNBackingLayer:0x6080000c5550; position = CGPoint (0 0); bounds = CGRect (0 0; 480 360); delegate = <SCNView: 0x100e03070 | scene=(null) sceneTime=0.000000 frame={{0, 0}, {480, 360}} pointOfView=(null)>; sublayers = (<AVCaptureVideoPreviewLayer: 0x608000026420>, <SCNBackingLayer: 0x6100000c2450>); opaque = YES; masksToBounds = YES; backgroundFilters = (
); filters = (
); shadowColor = (null); anchorPoint = CGPoint (0 0); NS_view = <SCNView: 0x100e03070 | scene=(null) sceneTime=0.000000 frame={{0, 0}, {480, 360}} pointOfView=(null)>>

对于子孙后代，我还应该指出其他字母（AFOW等）是在_subtreeDescription输出的底部定义的。

_subtreeDescription输出中的值是什么意思？

1 个答案: