iOS 10 上的 UIView 遮罩

Question

我有一个名为myView 的UIView 子类和一个名为myViewController 的UIViewController。

我将myView 添加为myViewController 中的子类，并且我还在其文件中屏蔽myView 子视图。

问题是当我屏蔽时，视图完全消失了。

有人知道为什么吗？

谢谢！

我的代码：

myViewController：

override func viewDidLoad() {
     let theView = myView(frame: CGRectZero)
     theView.translatesAutoresizingMaskIntoConstraints = false
     self.view.addSubview(theView)

     theView.bottomAnchor.constraintEqualToAnchor(self.view.bottomAnchor).active = true
     theView.leftAnchor.constraintEqualToAnchor(self.view.leftAnchor).active = true
     theView.rightAnchor.constraintEqualToAnchor(self.view.rightAnchor).active = true
     theView.heightAnchor.constraintEqualToAnchor(self.view.heightAnchor, multiplier: 0.17).active = true
}

myView：

override func layoutSubviews() {

        super.layoutSubviews()
        let ev = UIView(frame: self.bounds)
        ev.backgroundColor = UIColor.blueColor()
        ev.translatesAutoresizingMaskIntoConstraints = false
        self.addSubview(ev)

        ev.rightAnchor.constraintEqualToAnchor(self.rightAnchor).active = true
        ev.bottomAnchor.constraintEqualToAnchor(self.bottomAnchor).active = true
        ev.leftAnchor.constraintEqualToAnchor(self.leftAnchor).active = true
        ev.heightAnchor.constraintEqualToAnchor(self.heightAnchor, multiplier: 1.5).active = true

        let myPath: CGPathRef = PocketSVG.pathFromSVGFileNamed("CategoriesBar").takeUnretainedValue() //Creating a CGPath object using a  3rd party API
        var transform: CGAffineTransform = CGAffineTransformMakeScale(self.frame.size.width / 754.0, self.frame.size.height / 220.0) //Resizing it

        let transformedPath: CGPathRef = CGPathCreateMutableCopyByTransformingPath(myPath, &transform)! //Creating a re-sized CGPath

        let myShapeLayer = CAShapeLayer()
        myShapeLayer.path = transformedPath
        myShapeLayer.fillRule = kCAFillRuleEvenOdd

        let myMaskedView = UIView(frame: self.frame)
        myMaskedView.backgroundColor = UIColor.blackColor()
        myMaskedView.layer.mask = myShapeLayer
        ev.maskView = myMaskedView //THE PROBLEM. If I remove this line the view is visible (but it isn’t masked), but when I don’t the view just completely disappears!
}

注意：问题发生在我更新到 iOS 10 时，在 iOS 9 上一切正常。

Answer 1

'viewDidLoad()' 中的

'self.view.layoutSubviews()' 在实施 'UIView' 之前对我有用。它与iOS10中viewcontroller生命周期的变化有关。