简单填充(Swift 3.0, Alvin George回答):

  class NewLabel: UILabel {

        override func textRect(forBounds bounds: CGRect, limitedToNumberOfLines numberOfLines: Int) -> CGRect {
                return self.bounds.insetBy(dx: CGFloat(15.0), dy: CGFloat(15.0))
        }

        override func draw(_ rect: CGRect) {
                super.drawText(in: self.bounds.insetBy(dx: CGFloat(5.0), dy: CGFloat(5.0)))
        }

  }

简单的填充:

import UIKit

    class NewLabel: UILabel {

        override func textRectForBounds(bounds: CGRect, limitedToNumberOfLines numberOfLines: Int) -> CGRect {

            return CGRectInset(self.bounds, CGFloat(15.0), CGFloat(15.0))
        }

        override func drawRect(rect: CGRect) {

            super.drawTextInRect(CGRectInset(self.bounds,CGFloat(5.0), CGFloat(5.0)))
        }

    }

简单的方法

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        self.view.addSubview(makeLabel("my title",x: 0, y: 100, w: 320, h: 30))
    }

    func makeLabel(title:String, x:CGFloat, y:CGFloat, w:CGFloat, h:CGFloat)->UILabel{
        var myLabel : UILabel = UILabel(frame: CGRectMake(x,y,w,h))
        myLabel.textAlignment = NSTextAlignment.Right

        // inser last char to right
        var titlePlus1char = "\(title)1"
        myLabel.text = titlePlus1char
        var titleSize:Int = count(titlePlus1char)-1

        myLabel.textColor = UIColor(red:1.0, green:1.0,blue:1.0,alpha:1.0)
        myLabel.backgroundColor = UIColor(red: 214/255, green: 167/255, blue: 0/255,alpha:1.0)


        // create myMutable String
        var myMutableString = NSMutableAttributedString()

        // create myMutable font
        myMutableString = NSMutableAttributedString(string: titlePlus1char, attributes: [NSFontAttributeName:UIFont(name: "HelveticaNeue", size: 20)!])

        // set margin size
        myMutableString.addAttribute(NSFontAttributeName, value: UIFont(name: "HelveticaNeue", size: 10)!, range: NSRange(location: titleSize,length: 1))

        // set last char to alpha 0
        myMutableString.addAttribute(NSForegroundColorAttributeName, value: UIColor(red:1.0, green:1.0,blue:1.0,alpha:0), range: NSRange(location: titleSize,length: 1))

        myLabel.attributedText = myMutableString

        return myLabel
    }


    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

}

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.

我已经尝试了Swift 4.2，希望它对你有用!

@IBDesignable class PaddingLabel: UILabel {

    @IBInspectable var topInset: CGFloat = 5.0
    @IBInspectable var bottomInset: CGFloat = 5.0
    @IBInspectable var leftInset: CGFloat = 7.0
    @IBInspectable var rightInset: CGFloat = 7.0

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

    override var intrinsicContentSize: CGSize {
        let size = super.intrinsicContentSize
        return CGSize(width: size.width + leftInset + rightInset,
                      height: size.height + topInset + bottomInset)
    }   

    override var bounds: CGRect {
        didSet {
            // ensures this works within stack views if multi-line
            preferredMaxLayoutWidth = bounds.width - (leftInset + rightInset)
        }
    } 
}

或者你可以在这里使用CocoaPods https://github.com/levantAJ/PaddingLabel

吊舱' paddle标签'，'1.2'

没有故事板:

class PaddingLabel: UILabel {

    var topInset: CGFloat
    var bottomInset: CGFloat
    var leftInset: CGFloat
    var rightInset: CGFloat

    required init(withInsets top: CGFloat, _ bottom: CGFloat,_ left: CGFloat,_ right: CGFloat) {
        self.topInset = top
        self.bottomInset = bottom
        self.leftInset = left
        self.rightInset = right
        super.init(frame: CGRect.zero)
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

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

    override var intrinsicContentSize: CGSize {
        get {
            var contentSize = super.intrinsicContentSize
            contentSize.height += topInset + bottomInset
            contentSize.width += leftInset + rightInset
            return contentSize
        }
    }
}

用法:

let label = PaddingLabel(8, 8, 16, 16)
label.font = .boldSystemFont(ofSize: 16)
label.text = "Hello World"
label.backgroundColor = .black
label.textColor = .white
label.textAlignment = .center
label.layer.cornerRadius = 8
label.clipsToBounds = true
label.sizeToFit()

view.addSubview(label)

结果: