支持设置内边距的UILabel

UILabel with contentInset

import UIKit

class Label: UILabel {

  var contentInset: UIEdgeInsets = .zero {
    didSet {
      invalidateIntrinsicContentSize()
      setNeedsLayout()
    }
  }
  
  override func drawText(in rect: CGRect) {
    super.drawText(in: UIEdgeInsetsInsetRect(rect, contentInset))
  }
  
  override var intrinsicContentSize: CGSize {
    var size = super.intrinsicContentSize
    size.height += contentInset.top + contentInset.bottom
    size.width += contentInset.left + contentInset.right
    return size
  }
}