调整后启用adjustFontSizeToFitWidth的UILabel不会拥抱内容高度

Question

我有一个非常简单的UILabel示例，它将调整字体大小以适应宽度。但是，当它缩小文本时，它不会像提供的图像那样拥抱内容高度。使用adjustFontSizeToFitWidth时这是不可能的？

示例代码：

import Foundation
import UIKit

class SignUpViewController: UIViewController {
  override func viewDidLoad() {
    super.viewDidLoad()
    view.backgroundColor = UIColor.white
    let label = UILabel()
    view.addSubview(label)
    label.backgroundColor = UIColor.red
    label.adjustsFontSizeToFitWidth = true
    label.numberOfLines = 1
    label.minimumScaleFactor = 0.25
    label.font = UIFont.systemFont(ofSize: 80.0)
    label.text = "A really long bit of text that will need to shrink"
    label.translatesAutoresizingMaskIntoConstraints = false
    label.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 10.0).isActive = true
    label.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -10.0 ).isActive = true
    label.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
  }
}

截图：