如果你想在textRect周围添加2px的填充，只需要这样做:

let insets = UIEdgeInsets(top: -2, left: -2, bottom: -2, right: -2)
label.frame = UIEdgeInsetsInsetRect(textRect, insets)

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))
    }
}

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))
    }

}

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

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))
    }
}

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