错误。执行被中断，原因是：信号SIGABRT。在迅捷操场上

Question

当我试图在Xcode中运行我的游乐场时，我得到这个错误。

error: Execution was interrupted, reason: signal SIGABRT.
The process has been left at the point where it was interrupted, use "thread return -x" to return to the state before expression evaluation.

这是我的游乐场代码。

import UIKit
import PlaygroundSupport

class MyViewController : UIViewController {
    override func loadView() {
        let view = UIView()
        view.backgroundColor = .white

        let titleLabel = UILabel()
        titleLabel.frame = CGRect(x: 150, y: 200, width: 200, height: 20)
        titleLabel.text = "Title"
        titleLabel.textColor = .black

        let subtitleLabel = UILabel()
        subtitleLabel.text = "Subtitle"
        subtitleLabel.textColor = .gray
        subtitleLabel.frame = CGRect(x: 150, y: 200, width: 200, height: 20)

        NSLayoutConstraint.activate([
            titleLabel.bottomAnchor.constraint(equalToSystemSpacingBelow: subtitleLabel.topAnchor, multiplier: 10)
        ])

        view.addSubview(subtitleLabel)
        view.addSubview(titleLabel)
        self.view = view
    }
}
PlaygroundPage.current.liveView = MyViewController()

我如何解决这个错误？这是Xcode中的一个错误吗？还是我的代码有什么问题？

Answer 1

内 负载视图 方法重新排列代码，向上移动 添加子视图 在添加约束条件之前

view.addSubview(subtitleLabel)
view.addSubview(titleLabel)

NSLayoutConstraint.activate([
            titleLabel.bottomAnchor.constraint(equalToSystemSpacingBelow: subtitleLabel.topAnchor, multiplier: 10)
        ])

self.view = view

该错误将消失。