斯威夫特 4+

let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.firstLineHeadIndent = 10

// Swift 4.2++
label.attributedText = NSAttributedString(string: "Your text", attributes: [NSAttributedString.Key.paragraphStyle: paragraphStyle])

// Swift 4.1--
label.attributedText = NSAttributedString(string: "Your text", attributes: [NSAttributedStringKey.paragraphStyle: paragraphStyle])

如果你想在textRect周围添加2px的填充，只需要这样做:

let insets = UIEdgeInsets(top: -2, left: -2, bottom: -2, right: -2)
label.frame = UIEdgeInsetsInsetRect(textRect, insets)

斯威夫特 4+

class EdgeInsetLabel: UILabel {
    var textInsets = UIEdgeInsets.zero {
        didSet { invalidateIntrinsicContentSize() }
    }

    override func textRect(forBounds bounds: CGRect, limitedToNumberOfLines numberOfLines: Int) -> CGRect {
        let textRect = super.textRect(forBounds: bounds, limitedToNumberOfLines: numberOfLines)
        let invertedInsets = UIEdgeInsets(top: -textInsets.top,
                                          left: -textInsets.left,
                                          bottom: -textInsets.bottom,
                                          right: -textInsets.right)
        return textRect.inset(by: invertedInsets)
    }

    override func drawText(in rect: CGRect) {
        super.drawText(in: rect.inset(by: textInsets))
    }
}

用法:

let label = EdgeInsetLabel()
label.textInsets = UIEdgeInsets(top: 2, left: 6, bottom: 2, right: 6)

我在任何地方都没有看到这个答案。我的技巧是在标签上设置宽度限制，并在设置标签文本时调整宽度。

self.myLabel.text = myString;

UIFont * const font = [UIFont systemFontOfSize:17 weight:UIFontWeightRegular]; // Change to your own label font.

CGSize const size = CGSizeMake(INFINITY, 18); // 18 is height of label.

CGFloat const textWidth = [myString boundingRectWithSize:size options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName: font} context:nil].size.width;

self.myLabelWidthConstraint.constant = textWidth + 20; // 10 padding on each side. Also, set text alignment to centre.

子类UILabel。(File-New-File- CocoaTouchClass-make UILabel的子类)。

//  sampleLabel.swift

import UIKit

class sampleLabel: UILabel {

 let topInset = CGFloat(5.0), bottomInset = CGFloat(5.0), leftInset = CGFloat(8.0), rightInset = CGFloat(8.0)

 override func drawTextInRect(rect: CGRect) {

  let insets: UIEdgeInsets = UIEdgeInsets(top: topInset, left: leftInset, bottom: bottomInset, right: rightInset)
  super.drawTextInRect(UIEdgeInsetsInsetRect(rect, insets))

 }
 override func intrinsicContentSize() -> CGSize {
  var intrinsicSuperViewContentSize = super.intrinsicContentSize()
  intrinsicSuperViewContentSize.height += topInset + bottomInset
  intrinsicSuperViewContentSize.width += leftInset + rightInset
  return intrinsicSuperViewContentSize
 }
}

ViewController:

override func viewDidLoad() {
  super.viewDidLoad()

  let labelName = sampleLabel(frame: CGRectMake(0, 100, 300, 25))
  labelName.text = "Sample Label"
  labelName.backgroundColor =  UIColor.grayColor()

  labelName.textColor = UIColor.redColor()
  labelName.shadowColor = UIColor.blackColor()
  labelName.font = UIFont(name: "HelveticaNeue", size: CGFloat(22))
  self.view.addSubview(labelName)
 }

或者将Storyboard上的自定义UILabel类关联为Label的类。

我在公认的答案中略加修改。有一个问题，当左tinset和右tinset增加时，一部分文字会消失，b/c标签的宽度会变窄，但高度没有增加，如图所示:

要解决这个问题，你需要重新计算文本的高度，如下所示:

@IBDesignable class PaddingLabel: UILabel {

  @IBInspectable var topInset: CGFloat = 20.0
  @IBInspectable var bottomInset: CGFloat = 20.0
  @IBInspectable var leftInset: CGFloat = 20.0
  @IBInspectable var rightInset: CGFloat = 20.0

  override func drawTextInRect(rect: CGRect) {
    let insets = UIEdgeInsets(top: topInset, left: leftInset, bottom: bottomInset, right: rightInset)
    super.drawTextInRect(UIEdgeInsetsInsetRect(rect, insets))
  }

  override func intrinsicContentSize() -> CGSize {
    var intrinsicSuperViewContentSize = super.intrinsicContentSize()

    let textWidth = frame.size.width - (self.leftInset + self.rightInset)
    let newSize = self.text!.boundingRectWithSize(CGSizeMake(textWidth, CGFloat.max), options: NSStringDrawingOptions.UsesLineFragmentOrigin, attributes: [NSFontAttributeName: self.font], context: nil)
    intrinsicSuperViewContentSize.height = ceil(newSize.size.height) + self.topInset + self.bottomInset

    return intrinsicSuperViewContentSize
  }
}

和结果:

我希望能帮助一些和我处境相同的人。