类似于其他答案，但使用func类来动态地设置填充:

class UILabelExtendedView: UILabel
{
    var topInset: CGFloat = 4.0
    var bottomInset: CGFloat = 4.0
    var leftInset: CGFloat = 8.0
    var rightInset: CGFloat = 8.0

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

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

    func setPadding(top: CGFloat, left: CGFloat, bottom: CGFloat, right: CGFloat){
        self.topInset = top
        self.bottomInset = bottom
        self.leftInset = left
        self.rightInset = right
        let insets: UIEdgeInsets = UIEdgeInsets(top: top, left: left, bottom: bottom, right: right)
        super.drawText(in: UIEdgeInsetsInsetRect(self.frame, insets))
    }
}

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。

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)
    }
}

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)))
        }

    }

Swift 3代码及其实现示例

class UIMarginLabel: UILabel {

    var topInset:       CGFloat = 0
    var rightInset:     CGFloat = 0
    var bottomInset:    CGFloat = 0
    var leftInset:      CGFloat = 0

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

class LabelVC: UIViewController {

    //Outlets
    @IBOutlet weak var labelWithMargin: UIMarginLabel!

    override func viewDidLoad() {
        super.viewDidLoad()

        //Label settings.
        labelWithMargin.leftInset = 10
        view.layoutIfNeeded()
    }
}

不要忘记在故事板标签对象中添加类名UIMarginLabel。 编码快乐!