How do I programmatically add an NSView in Swift on macOS

Question

Trying to add a simple NSView programmatically.

It does not appear.

** ANSWER **: Do .wantsLayer = true before .backgroundColor = .black

I set the color to black so I expect there to be a black square in the window.

I am using Xcode 10.2 Swift 5

import Cocoa

class ViewController: NSViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        let newView = NSView(frame: NSRect(x: 10,y: 10, width: 100,height: 100))
        newView.layer?.backgroundColor = .black
        newView.wantsLayer = true
        self.view.addSubview(newView)
    }
}

you need to set wantsLayer to true before setting the layer backgroundColor — Leo Dabus, Apr 19 '19 at 11:50

score 6 · Accepted Answer · answered Apr 19 '19 at 11:46

6

import Cocoa

let frame = CGRect(origin: .zero, size: CGSize(width: 100, height: 100))
let view = NSView(frame: frame)

view.wantsLayer = true
view.layer?.backgroundColor = NSColor.black.cgColor
self.view.addSubView(view)

answered Apr 19 '19 at 11:46

İsa GİRİŞKEN

216
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self.view.addSubView(view) not view addSubView – İsa GİRİŞKEN Apr 19 '19 at 11:48
3

An explanation about why this code solves OP issue it is essential for helping future readers – Leo Dabus Apr 19 '19 at 11:51
Btw not my downvote but your code without the ViewController makes no sense. `self.view` instance only exists inside a NSViewController method or computed property. – Leo Dabus Apr 19 '19 at 12:03

How do I programmatically add an NSView in Swift on macOS

1 Answers1