将 CAConstraints 与 NSView 层一起使用

Question

我希望 NSView 的子层与视图一起 grow/shrink，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匹配视图，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：看不到子层，除非明确设置了它的框架。还尝试了相反方向的约束：从层到子层 - 结果相同

Answer 1

您没有在代码中设置 CAConstraintLayerManager：

layer.layoutManager = CAConstraintLayoutManager()

查看片段：

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

将 CAConstraints 与 NSView 层一起使用

Using CAConstraints with NSView layers

macos

layer

nsview