子图层添加后未显示

我正在尝试"resizeLayer"通过对UIView selectedShape进行子分层来将其添加到UIView中selectedShape

let sublayer = CALayer()
sublayer.bounds = selectedShape.bounds //even when inserted this line, sublayer still doesn't show up
sublayer.frame = selectedShape.frame
sublayer.contents = UIImage(named: "resizeLayer")
selectedShape?.layer.addSublayer(sublayer)

但是当我运行代码时，我根本看不到该层

我什至尝试"resizeLayer"通过UIView来查看图像"selectedShape"

let resizeFrame = UIImageView(image: UIImage(named: "resizeLayer"))
resizeFrame.frame = selectedShape.frame
resizeFrame.contentMode = UIViewContentMode.ScaleAspectFill
selectedShape.addSubview(resizeFrame)

但是，仍然"resizeLayer"没有出现！

仅当我"resizeLayer"在整体视图中添加时，它才会显示：

let resizeFrame = UIImageView(image: UIImage(named: "resizeLayer"))
resizeFrame.frame = selectedShape.frame
resizeFrame.contentMode = UIViewContentMode.ScaleAspectFill
selectedShape.addSubview(resizeFrame)     
self.view.insertSubview(resizeFrame, aboveSubview: selectedShape) //add this line

任何帮助，将不胜感激！

如果相关，这就是我所做的 selectedShape

selectedShape = UIView(frame: CGRect(x: 0, y: 0, width: 60, height: 60))
selectedShape.layer.cornerRadius = 10
selectedShape.backgroundColor = UIColor.blueColor()
canvas.addSubview(selectedShape) //canvas is the view I'm adding selectedShape to

这是"resizeLayer"我要添加的图像

蓝色正方形是selectedShape。如您所见，该图层未显示。

我想发生什么

您正在使用整个框架selectedShape。您应该只使用widthand和height因为x并且y应该为零。图像被添加到selectedShape该点，因此该点(0,0)位于selectedShape视图的左上方。

resizeFrame.frame = CGRect(origin: CGPointZero, size: selectedShape.frame.size)

我承认，这让我难过的时间比原本应该的更长。