Add CATextLayer on Top of NSImageView

问题

I'm trying to display text on top of an NSImage.I use the following code

                    let myTextLayer = CATextLayer()
                    myTextLayer.string = "My text"
                    myTextLayer.foregroundColor = NSColor.cyan.cgColor
                    myTextLayer.frame = self.img_view.bounds
                    self.img_view.layer=myTextLayer;

This keeps producing empty NSImageView

回答1:

You needs explicitly say NSImageView wantsLayer before use layers, like below

self.img_view.wantsLayer = true

let myTextLayer = CATextLayer()
myTextLayer.string = "My text"
myTextLayer.foregroundColor = NSColor.cyan.cgColor
myTextLayer.frame = self.img_view.bounds

self.img_view.layer.addSublayer(myTextLayer)

来源：https://stackoverflow.com/questions/61309916/add-catextlayer-on-top-of-nsimageview