Child already has a owner, it must be removed first.

[srv7]

func setup(_ x: String) {
        subviews.forEach { $0.removeFromSuperview() }
        flex.padding(15).define { flex in
            flex.addItem().width(100%).direction(.row).justifyContent(.spaceAround)
                .define { flex in
                    for i in 1 ... 4 {
                        let label = UILabel()
                        label.text = "\(x)--\(i)"
                        flex.addItem(label).height(44).width(20%)
                    }
                }

            flex.addItem().height(60).marginTop(15).direction(.row).alignItems(.stretch).define { flex in
                flex.addItem(btnA).grow(1).shrink(1)
                flex.addItem().width(11)
                flex.addItem(btnB).grow(1).shrink(1)
            }
        }
    }

call setup method twice and then crash.

[email protected]
function YGAttachNodesFromViewHierachy(UIView *const view)

[email protected]
function YGAttachNodesFromViewHierachy(UIView *const view)

so, why remove these code

[srv7]

import FlexLayout
import UIKit

class ViewController: UIViewController {
    
    let container = UIView()
    
    lazy var kindView: AKindView = {
        let view = AKindView()
        return view
    }()

    override func viewDidLoad() {
        super.viewDidLoad()
        navigationItem.rightBarButtonItem = UIBarButtonItem(title: "set", style: .plain, target: self, action: #selector(changeAction))
        view.addSubview(container)
        container.frame = view.bounds
        container.flex.paddingTop(100).direction(.column).justifyContent(.center).alignItems(.stretch).define { flex in
            flex.addItem(kindView)
        }
        kindView.setup("A")
        container.flex.layout(mode: .adjustHeight)
    }
    @objc func changeAction() {
        kindView.setup("B")
        container.flex.layout(mode: .adjustHeight)
    }
}

import FlexLayout
import UIKit

class AKindView: UIView {
    lazy var btnA: UIButton = {
        let btn = UIButton()
        btn.setTitle("ABC", for: .normal)
        btn.backgroundColor = .orange
        return btn
    }()

    lazy var btnB: UIButton = {
        let btn = UIButton()
        btn.setTitle("DEF", for: .normal)
        btn.backgroundColor = .orange
        return btn
    }()

    override init(frame: CGRect) {
        super.init(frame: frame)
        backgroundColor = .white
    }

    @available(*, unavailable)
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    func setup(_ x: String) {
        subviews.forEach { $0.removeFromSuperview() }
        flex.padding(15).define { flex in
            flex.addItem().width(100%).direction(.row).justifyContent(.spaceAround)
                .define { flex in
                    for i in 1 ... 4 {
                        let label = UILabel()
                        label.text = "\(x)--\(i)"
                        flex.addItem(label).height(44).width(20%)
                    }
                }

            flex.addItem().height(60).marginTop(15).direction(.row).alignItems(.stretch).define { flex in
                flex.addItem(btnA).grow(1).shrink(1)
                flex.addItem().width(11)
                flex.addItem(btnB).grow(1).shrink(1)
            }
        }
    }
}

[MQLiu]

Same issue, has anyone fixed it yet？

[kennethpu]

The issue here is that when setup() is called multiple times btnA and btnB wind up moving between different superviews. This means their corresponding node still has an associated parent when YGNodeInsertChild() is called, triggering the assert.

It looks like we previously had modified YGLayout to clean up these parent references (c303faa) but this was overwritten when we updated to Yoga 2.0. I have a PR (#242) to restore these lines and keep us from hitting the assert.

[MQLiu]

这是来自QQ邮箱的自动回复邮件。您好，已收到您的邮件。谢谢！

[lucdion]

The fix will be merged today.

[lucdion]

The fix has been released.