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.
    }

}

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。

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)
    }
}

objective - c

基于Tai Le的回答，它在一个Interface Builder Designable中实现了这个特性，下面是Objective-C版本。

把这个放在YourLabel.h文件中:

@interface YourLabel : UILabel

@property IBInspectable CGFloat topInset;
@property IBInspectable CGFloat bottomInset;
@property IBInspectable CGFloat leftInset;
@property IBInspectable CGFloat rightInset;

@end

这个会放在yourlabel。m文件中:

IB_DESIGNABLE

@implementation YourLabel

#pragma mark - Super

- (instancetype)initWithCoder:(NSCoder *)aDecoder {
    self = [super initWithCoder:aDecoder];
    if (self) {
        self.topInset = 0;
        self.bottomInset = 0;
        self.leftInset = 0;
        self.rightInset = 0;
    }
    return self;
}

- (void)drawTextInRect:(CGRect)rect {
    UIEdgeInsets insets = UIEdgeInsetsMake(self.topInset, self.leftInset, self.bottomInset, self.rightInset);
    [super drawTextInRect:UIEdgeInsetsInsetRect(rect, insets)];
}

- (CGSize)intrinsicContentSize {
    
    CGSize size = [super intrinsicContentSize];
    return CGSizeMake(size.width + self.leftInset + self.rightInset,
                      size.height + self.topInset + self.bottomInset);
}

@end

然后，在XIB文件或故事板中指定类后，您可以直接在Interface Builder中修改YourLabel嵌入，嵌入的默认值为零。

你可以从IB正确地做到:

将文本更改为带属性

使用"…"进入下拉列表

你会看到一些填充属性的行，段落和文本变化缩进第一行或任何你想要的

检查结果

如果你想使用UILabel

class UILabel : UIKit.UILabel {
    var insets = 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: -insets.top,
                                          left: -insets.left,
                                          bottom: -insets.bottom,
                                          right: -insets.right)
        return textRect.inset(by: invertedInsets)
    }

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