我有一个UILabel,我想在顶部和底部添加空格。在限制最小高度的情况下,我将其修改为:

为了做到这一点,我使用了:

override func drawTextInRect(rect: CGRect) {
    var insets: UIEdgeInsets = UIEdgeInsets(top: 0.0, left: 10.0, bottom: 0.0, right: 10.0)
    super.drawTextInRect(UIEdgeInsetsInsetRect(rect, insets))
}

但我必须找到不同的方法,因为如果我写了超过两行,问题是一样的:


当前回答

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])

其他回答

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))
    }
}

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))
    }
}

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
    }
}

一个实用的解决方案是添加与主标签高度和颜色相同的空白标签。将主标签的前导/尾距设置为零,对齐垂直中心,并设置所需的宽度。

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)
    }
}