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)

斯威夫特4

易于使用的解决方案，可用于项目中的所有UILabel子。

例子:

let label = UILabel()
    label.<Do something>
    label.padding = UIEdgeInsets(top: 0, left: 16, bottom: 0, right: 0)

UILabel扩展

import UIKit

extension UILabel {
    private struct AssociatedKeys {
        static var padding = UIEdgeInsets()
    }

    public var padding: UIEdgeInsets? {
        get {
            return objc_getAssociatedObject(self, &AssociatedKeys.padding) as? UIEdgeInsets
        }
        set {
            if let newValue = newValue {
                objc_setAssociatedObject(self, &AssociatedKeys.padding, newValue as UIEdgeInsets?, objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN_NONATOMIC)
            }
        }
    }

    override open func draw(_ rect: CGRect) {
        if let insets = padding {
            self.drawText(in: rect.inset(by: insets))
        } else {
            self.drawText(in: rect)
        }
    }

    override open var intrinsicContentSize: CGSize {
        guard let text = self.text else { return super.intrinsicContentSize }

        var contentSize = super.intrinsicContentSize
        var textWidth: CGFloat = frame.size.width
        var insetsHeight: CGFloat = 0.0
        var insetsWidth: CGFloat = 0.0

        if let insets = padding {
            insetsWidth += insets.left + insets.right
            insetsHeight += insets.top + insets.bottom
            textWidth -= insetsWidth
        }

        let newSize = text.boundingRect(with: CGSize(width: textWidth, height: CGFloat.greatestFiniteMagnitude),
                                        options: NSStringDrawingOptions.usesLineFragmentOrigin,
                                        attributes: [NSAttributedString.Key.font: self.font], context: nil)

        contentSize.height = ceil(newSize.size.height) + insetsHeight
        contentSize.width = ceil(newSize.size.width) + insetsWidth

        return contentSize
    }
}

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.

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

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)
    }
}