objective - c

基于Tai Le的回答，它在一个Interface Builder Designable中实现了这个特性，下面是Objective-C版本。

把这个放在YourLabel.h文件中:

@interface YourLabel : UILabel

@property IBInspectable CGFloat topInset;
@property IBInspectable CGFloat bottomInset;
@property IBInspectable CGFloat leftInset;
@property IBInspectable CGFloat rightInset;

@end

这个会放在yourlabel。m文件中:

IB_DESIGNABLE

@implementation YourLabel

#pragma mark - Super

- (instancetype)initWithCoder:(NSCoder *)aDecoder {
    self = [super initWithCoder:aDecoder];
    if (self) {
        self.topInset = 0;
        self.bottomInset = 0;
        self.leftInset = 0;
        self.rightInset = 0;
    }
    return self;
}

- (void)drawTextInRect:(CGRect)rect {
    UIEdgeInsets insets = UIEdgeInsetsMake(self.topInset, self.leftInset, self.bottomInset, self.rightInset);
    [super drawTextInRect:UIEdgeInsetsInsetRect(rect, insets)];
}

- (CGSize)intrinsicContentSize {
    
    CGSize size = [super intrinsicContentSize];
    return CGSizeMake(size.width + self.leftInset + self.rightInset,
                      size.height + self.topInset + self.bottomInset);
}

@end

然后，在XIB文件或故事板中指定类后，您可以直接在Interface Builder中修改YourLabel嵌入，嵌入的默认值为零。

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。

我的解决方案与人们回答的类似，但添加了sizeThatFits来帮助UIKit找出正确的大小。

class InsetLabel : UILabel {
    @objc var textInsets: UIEdgeInsets = .zero

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

    override func sizeThatFits(_ size: CGSize) -> CGSize {
        var s = super.sizeThatFits(CGSize(width: size.width - (textInsets.left + textInsets.right), height: size.height - (textInsets.top + textInsets.bottom)))
        s.height += textInsets.top + textInsets.bottom
        return s
    }
}

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))
    }
}

只需使用一个UIView作为一个superview，并定义一个固定的边距标签与自动布局。

如果在应用填充时遇到文本修剪问题，请使用此代码。

@IBDesignable class PaddingLabel: UILabel {

    @IBInspectable var topInset: CGFloat = 5.0
    @IBInspectable var bottomInset: CGFloat = 5.0
    @IBInspectable var leftInset: CGFloat = 5.0
    @IBInspectable var rightInset: CGFloat = 5.0

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

    override var intrinsicContentSize: CGSize {
        var intrinsicSuperViewContentSize = super.intrinsicContentSize
        let textWidth = frame.size.width - (self.leftInset + self.rightInset)
        let newSize = self.text!.boundingRect(with: CGSize(textWidth, CGFloat.greatestFiniteMagnitude), options: NSStringDrawingOptions.usesLineFragmentOrigin, attributes: [NSFontAttributeName: self.font], context: nil)
        intrinsicSuperViewContentSize.height = ceil(newSize.size.height) + self.topInset + self.bottomInset
        return intrinsicSuperViewContentSize
    }
}

extension CGSize{
    init(_ width:CGFloat,_ height:CGFloat) {
        self.init(width:width,height:height)
    }
}