无法激活锚点约束

Question

所以，我正在尝试以编程方式创建一个SceneView

class ViewController: UIViewController, ARSCNViewDelegate {
    var sceneView: ARSCNView = ARSCNView()
    let configuration = ARWorldTrackingConfiguration()

    override func viewDidLoad() {
        super.viewDidLoad()

        self.sceneView.debugOptions = [ARSCNDebugOptions.showFeaturePoints, ARSCNDebugOptions.showWorldOrigin]
        self.configuration.planeDetection = .horizontal
        self.sceneView.session.run(configuration)
        self.sceneView.delegate = self
        self.sceneView.autoenablesDefaultLighting = true

        //add autolayout contstraints
        self.sceneView.translatesAutoresizingMaskIntoConstraints = false
        self.sceneView.topAnchor.constraint(equalTo: self.view.topAnchor).isActive = true
        self.sceneView.leftAnchor.constraint(equalTo: self.view.leftAnchor).isActive = true
        self.sceneView.rightAnchor.constraint(equalTo: self.view.rightAnchor).isActive = true
        self.sceneView.bottomAnchor.constraint(equalTo: self.view.bottomAnchor).isActive = true

    }

    func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {
        guard anchor is ARPlaneAnchor else {return}
    }
}

但我收到此错误消息：

由于未捕获的异常“
NSGenericException”而终止应用程序，原因：“无法激活具有锚点的约束，并且它们没有共同的祖先。约束或其锚点是否引用了不同视图层次结构中的项目？那是非法的。

这是部分发生的\\add autolayout contstraints。如何为该元素添加约束？

Answer 1

dan是正确的，您需要先添加sceneView为子视图，然后才能锚定它。尝试这样的事情：

view.addSubview(sceneView)
sceneView.anchor(top: self.view.topAnchor, left: self.view.leftAnchor, bottom: self.view.bottomAnchor, right: self.view.rightAnchor, paddingTop: 0, paddingLeft: 0, paddingBottom: 0, paddingRight: 0, width: 0, height: 0)