向UIDynamicAnimator添加32个以上的UIFieldBehaviors会导致SIGABRT

Question

我有以下代码。当我迭代25次（5 * 5）时，它可以正常工作。当我迭代36次（for循环中为6 * 6）时，它会因SIGABRT而崩溃。我粘贴了错误的图片（Xcode中的Playgrounds不允许我复制粘贴它）。这是内部错误，是否在某处定义了32个行为限制，或者这是我的代码中的错误？谢谢！

//: A UIKit based Playground for presenting user interface

import UIKit
import PlaygroundSupport

class MyViewController : UIViewController {
    var animator : UIDynamicAnimator!

    var springfields : [UIFieldBehavior] = []

    override func loadView() {
        let view = UIView()
        view.backgroundColor = .white
        animator = UIDynamicAnimator(referenceView: view)

        for i in 1...6 {
            for j in 1...6 {
                let newView = UIView()
                let dotwidth = 12
                newView.layer.cornerRadius = CGFloat(dotwidth/2);
                newView.frame = CGRect(x:20+i*25, y:20+j*25, width:dotwidth, height:dotwidth)
                newView.clipsToBounds = true
                newView.backgroundColor = .black

                let newSpringField = UIFieldBehavior.springField()
                springfields.append(newSpringField)
                newSpringField.addItem(newView)
                newSpringField.position = newView.center

                view.addSubview(newView)

                animator.addBehavior(newSpringField)
            }
        }

        self.view = view
    }
}
// Present the view controller in the Live View window
PlaygroundPage.current.liveView = MyViewController()
PlaygroundPage.current.needsIndefiniteExecution = true

Answer 1

在应用程序中运行代码，调试控制台输出为：

  

***由于未捕获的异常“无效关联”而终止应用程序，原因：“ UIDynamicAnimator最多支持32个不同的字段”