在Swift 3中

最好最简单的方法

class UILabelPadded: UILabel {
     override func drawText(in rect: CGRect) {
     let insets = UIEdgeInsets.init(top: 0, left: 5, bottom: 0, right: 5)
     super.drawText(in: UIEdgeInsetsInsetRect(rect, insets))
    }

}

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])

如果你不想或需要在Storyboard中使用@IBInspectable / @IBDesignable UILabel(我认为那些渲染太慢了)，那么使用UIEdgeInsets而不是4个不同的cgfloat会更干净。

Swift 4.2的代码示例:

class UIPaddedLabel: UILabel {
    var padding = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)

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

    public override var intrinsicContentSize: CGSize {
        let size = super.intrinsicContentSize
        return CGSize(width: size.width + padding.left + padding.right,
                      height: size.height + padding.top + padding.bottom)
    }
}

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

Swift 3、iOS10解决方案:

open class UIInsetLabel: UILabel {

    open var insets : UIEdgeInsets = UIEdgeInsets() {
        didSet {
            super.invalidateIntrinsicContentSize()
        }
    }

    open override var intrinsicContentSize: CGSize {
        var size = super.intrinsicContentSize
        size.width += insets.left + insets.right
        size.height += insets.top + insets.bottom
        return size
    }

    override open func drawText(in rect: CGRect) {
        return super.drawText(in: UIEdgeInsetsInsetRect(rect, insets))
    }
}

就像其他答案一样，但它修复了一个bug:

当标签。宽度由自动布局控制，有时文本会被裁剪。

@IBDesignable
class InsetLabel: UILabel {

    @IBInspectable var topInset: CGFloat = 4.0
    @IBInspectable var leftInset: CGFloat = 4.0
    @IBInspectable var bottomInset: CGFloat = 4.0
    @IBInspectable var rightInset: CGFloat = 4.0

    var insets: UIEdgeInsets {
        get {
            return UIEdgeInsets.init(top: topInset, left: leftInset, bottom: bottomInset, right: rightInset)
        }
        set {
            topInset = newValue.top
            leftInset = newValue.left
            bottomInset = newValue.bottom
            rightInset = newValue.right
        }
    }

    override func sizeThatFits(_ size: CGSize) -> CGSize {
        var adjSize = super.sizeThatFits(size)
        adjSize.width += leftInset + rightInset
        adjSize.height += topInset + bottomInset
        return adjSize
    }

    override var intrinsicContentSize: CGSize {
        let systemContentSize = super.intrinsicContentSize
        let adjustSize = CGSize(width: systemContentSize.width + leftInset + rightInset, height: systemContentSize.height + topInset +     bottomInset)
        if adjustSize.width > preferredMaxLayoutWidth && preferredMaxLayoutWidth != 0 {
            let constraintSize = CGSize(width: bounds.width - (leftInset + rightInset), height: .greatestFiniteMagnitude)
            let newSize = super.sizeThatFits(constraintSize)
            return CGSize(width: systemContentSize.width, height: ceil(newSize.height) + topInset + bottomInset)
        } else {
            return adjustSize
        }
    }

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