我通过子类化UILabel和重写drawTextInRect来解决这个问题:

- (void)drawTextInRect:(CGRect)rect {
    UIEdgeInsets insets = {0, 5, 0, 5};
    [super drawTextInRect:UIEdgeInsetsInsetRect(rect, insets)];
}

斯威夫特3.1:

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4.2.1:准备

override func drawText(in rect: CGRect) {
    let insets = UIEdgeInsets(top: 0, left: 5, bottom: 0, right: 5)
    super.drawText(in: rect.inset(by: insets))
}

你可能已经猜到了，这是对tc的改编。的答案。它有两个优点:

没有必要通过发送sizeToFit消息来触发它 它只保留标签框架——如果你的标签有背景，而你不想让它缩小，这很方便

这是我找到的最简单的解决方法:

斯威夫特4

class CustomLabel: UILabel{
    override func drawText(in rect: CGRect) {
        super.drawText(in: rect.inset(by: UIEdgeInsets.init(top: 10, left: 10, bottom: 10, right: 10)))
    }
}

确保在代码和故事板中都将标签设置为CustomLabel类。

如果你不想使用一个额外的父视图来设置背景，你可以子类化UILabel并重写textRectForBounds: limitedtonumberolines:。我会添加一个textEdgeInsets属性或类似的，然后做

- (CGRect)textRectForBounds:(CGRect)bounds limitedToNumberOfLines:(NSInteger)numberOfLines
{
  return [super textRectForBounds:UIEdgeInsetsInsetRect(bounds,textEdgeInsets) limitedToNumberOfLines:numberOfLines];
}

为了健壮性，你可能还想在setTextEdgeInsets:中调用[self setNeedsDisplay]，但我通常不这么做。

为了消除单行标签的垂直填充，我做了:

// I have a category method setFrameHeight; you'll likely need to modify the frame.
[label setFrameHeight:font.pointSize];

或者，不带类别，使用:

CGRect frame = label.frame;
frame.size.height = font.pointSize;
label.frame = frame;

Swift 4版的blyabtroi解决方案

let leadingMargin: CGFloat = 10
let trailingMargin: CGFloat = 10

let style = NSMutableParagraphStyle()
style.alignment = .justified
style.firstLineHeadIndent = leadingMargin
style.headIndent = leadingMargin
style.tailIndent = trailingMargin

label.attributedText = NSAttributedString(string: "Label with margins", 
                                          attributes: [NSAttributedStringKey.paragraphStyle: style])

Swift 3 &自动布局兼容版本:

class InsetLabel: UILabel {

    var insets = UIEdgeInsets()

    convenience init(insets: UIEdgeInsets) {
        self.init(frame: CGRect.zero)
        self.insets = insets
    }

    convenience init(dx: CGFloat, dy: CGFloat) {
        let insets = UIEdgeInsets(top: dy, left: dx, bottom: dy, right: dx)
        self.init(insets: insets)
    }

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

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