Why can't I auto-fit text of a UILabel from code, but I can through the IB?

Question

Scenario: I merely want to able to fit a string within a UILabel per target device.
That is, on one iPad model the string is truncated. On another it isn't.
I suspect the application is more code-centric vs IB.
So I want to be able to work with the UILabel programmatically.

Here's the code:

class ViewController: UIViewController {
    @IBOutlet var myLabel: UILabel!

    @IBAction func addMessageAction(_ sender: UIBarButtonItem) {
        let msg = "Mother had a feeling, I might be too appealing. But I can understand."
        myLabel.text = msg
        myLabel.numberOfLines = 0
        myLabel.adjustsFontForContentSizeCategory = true
        myLabel.sizeToFit()

        myLabel.lineBreakMode = .byTruncatingTail
        myLabel.minimumScaleFactor = 0.5
    }

    @IBAction func exitAction(_ sender: UIBarButtonItem) {
        exit(0)
    }
}

Here's the screen after I pressed the 'message' button:

This only appear to work with I set the UILabel properties within IB.

Why doesn't it work via code?

Answer 1

I tried your code and its working perfectly. Is there any Autolayout constraint mismatch ?

You can do one thing to this change the font size to fit the width of the label

myLabel.adjustsFontSizeToFitWidth = true