将CAConstraints与NSView图层一起使用

Question

我希望NSView的子层随视图一起增长/缩小，以便其框架自动匹配视图的边界，而无需显式重置它。

假设视图的主层始终与视图匹配，我尝试了以下代码：

let layer = self.layer!  // It is guaranteed to exist
layer.backgroundColor = NSColor.white
layer.name = "MainLayer"
let sublayer = CALayer()
sublayer.backgroundColor = NSColor.black

layer.addSublayer(sublayer)

sublayer.addConstraint(CAConstraint.init(attribute: .width, relativeTo: "MainLayer", attribute: CAConstraintAttribute.width))
sublayer.addConstraint(CAConstraint.init(attribute: .height, relativeTo: "MainLayer", attribute: CAConstraintAttribute.height))

猜猜看：除非明确设置了子帧，否则看不到子层。 还尝试了相反方向的约束：从层到子层-相同的结果

Answer 1

您未在代码中设置CAConstraintLayerManager：

layer.layoutManager = CAConstraintLayoutManager()

请参见中的代码段：

https://developer.apple.com/documentation/quartzcore/caconstraintlayoutmanager