无法使用锚激活约束

Posted 2023-03-23

【中文标题】无法使用锚激活约束

【英文标题】：Unable to activate constraint with anchors

【发布时间】：2018-04-20 10:51:49

【问题描述】：

所以，我正在尝试以编程方式创建一个场景视图

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：“无法使用锚点激活约束 <0x1c0278700><0x1c426db40>

【参考方案1】：

dan is right，您需要将sceneView 添加为子视图，然后才能锚定它。试试这样的：

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)

【讨论】：

其实他是对的，其实我之前也试过，不知道为什么不行，反正谢谢@dan和thomas

嘿@Thomas，非常感谢您的详细回答！我和我的团队在一个问题上停留了好几天啊：/我发布了一个有趣的问题：***.com/questions/63662318/…希望您提出建议！