约束引起的崩溃

作者: 故人
发布时间: 2024-01-15 08:39:41 (3月前)
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5 条回复

0#
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哈哈哈哈 | 2019-08-31 10-32

<div class =“post-text”itemprop =“text”> <P> 你忘了给你的头一个框架。试试这个： </p> <pre> <code> class ViewController: UIViewController { private var head: UIView! override func viewDidLoad() { super.viewDidLoad() setup() } private func setup() { head = UIView(frame: .zero) head.translatesAutoresizingMaskIntoConstraints = false head.backgroundColor = .red self.view.addSubview(head) head.leftAnchor.constraint(equalTo: self.view.leftAnchor, constant: 16).isActive = true head.rightAnchor.constraint(equalTo: self.view.rightAnchor, constant: -16).isActive = true head.topAnchor.constraint(equalTo: self.view.topAnchor, constant: 16).isActive = true head.bottomAnchor.constraint(equalTo: self.view.bottomAnchor, constant: -16).isActive = true } } </code> </pre> </DIV>

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1#
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Moso31 | 2019-08-31 10-32

<div class =“post-text”itemprop =“text”> <P> 当我在您的代码中跟踪问题时，您忘了添加 <code> head.translatesAutoresizingMaskIntoConstraints = false </code> 为了 <code> head </code> 查看并删除 <code> self.view.translatesAutoresizingMaskIntoConstraints = false </code> </p> <P> 所以只有改变是，添加这一行。 </p> <pre> <code> let head = UIView.init() head.backgroundColor = UIColor.cyan head.translatesAutoresizingMaskIntoConstraints = false self.view.addSubview(head) //This new line added head.translatesAutoresizingMaskIntoConstraints = false head.leadingAnchor.constraint(equalTo: self.view.layoutMarginsGuide.leadingAnchor).isActive = true head.topAnchor.constraint(equalTo: self.view.layoutMarginsGuide.topAnchor).isActive = true head.trailingAnchor.constraint(equalTo: self.view.layoutMarginsGuide.trailingAnchor).isActive = true head.heightAnchor.constraint(equalToConstant: 44).isActive = true </code> </pre> </DIV>

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2#
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我头上有犄角 | 2019-08-31 10-32

<div class =“post-text”itemprop =“text”> <P> 我尝试了与XCode版本10.0（10A255）一起发布的相同代码，它的工作正常，但显示XCode版本10.1（10B61）崩溃。 </p> </DIV>

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3#
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筱梨 | 2019-08-31 10-32

<div class =“post-text”itemprop =“text”> <P> 我已经尝试过这段代码并且在我身边工作得很好。请检查： </p> <pre> <code> var head: UIView? = nil override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after loading the view, typically from a nib. head = UIView.init() head?.backgroundColor = UIColor.cyan self.view.addSubview(head!) head?.translatesAutoresizingMaskIntoConstraints = false head?.leadingAnchor.constraint(equalTo: self.view.layoutMarginsGuide.leadingAnchor).isActive = true head?.topAnchor.constraint(equalTo: self.view.layoutMarginsGuide.topAnchor).isActive = true head?.trailingAnchor.constraint(equalTo: self.view.layoutMarginsGuide.trailingAnchor).isActive = true head?.heightAnchor.constraint(equalToConstant: 44).isActive = true } </code> </pre> <P> 不要写这行你不需要这个： </p> <pre> <code> self.view.translatesAutoresizingMaskIntoConstraints = false </code> </pre> </DIV>

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