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.
    }

}

一个实用的解决方案是添加与主标签高度和颜色相同的空白标签。将主标签的前导/尾距设置为零，对齐垂直中心，并设置所需的宽度。

只需使用一个UIView作为一个superview，并定义一个固定的边距标签与自动布局。

严格适用于单行标签:(2021语法)

对于任何谷歌这里谁需要在严格单行标签填充(如节标题或其他列表项)，

语法发生了很大变化。当心互联网上的过时信息。

下面是要复制和粘贴的确切类:

// add 100 above, 50 padding below a SINGLE-LINE label
import UIKit
class SingleLineLabelWithSpacing: UILabel {
    // STRICTLY for SINGLE LINE labels
    // only works with SINGLE LINE labels

    override func drawText(in rect: CGRect) {
        let insets: UIEdgeInsets = UIEdgeInsets(
               top: 100, left: 0, bottom: 50, right: 0)
        super.drawText(in: rect.inset(by: insets))
    }

    override var intrinsicContentSize: CGSize {
        var ic = super.intrinsicContentSize
        ic.height = ic.height + 150
        return ic
    }
}

在这个例子中，填充大于或小于100/50。

当您有任何类型的滚动列表、提要或其他列表时，这是通常要做的事情。

这样你就不必考虑标题上方/下方的空格，用户名等等——你只需要把它放到堆栈视图或其他任何情况下。

当然，当设计师想要调整时，你也可以在任何地方同时更改这两个值。

提醒:如果你想真正填充一个UILabel，让它无论文本行数、动态大小单元格、动画等等都能完美工作，这是非常复杂的。唯一正确的答案是:https://stackoverflow.com/a/58876988/294884

我的解决方案与人们回答的类似，但添加了sizeThatFits来帮助UIKit找出正确的大小。

class InsetLabel : UILabel {
    @objc var textInsets: UIEdgeInsets = .zero

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

    override func sizeThatFits(_ size: CGSize) -> CGSize {
        var s = super.sizeThatFits(CGSize(width: size.width - (textInsets.left + textInsets.right), height: size.height - (textInsets.top + textInsets.bottom)))
        s.height += textInsets.top + textInsets.bottom
        return s
    }
}

根据Swift 4.2 (Xcode 10 beta 6)"UIEdgeInsetsInsetRect"已弃用。 我还将类声明为public以使其更有用。

public class UIPaddedLabel: 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

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

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

    public override func sizeToFit() {
        super.sizeThatFits(intrinsicContentSize)
    }
}