blyabtroi的asnwer在Swift中转换(不需要子类化)

let style: NSMutableParagraphStyle = NSParagraphStyle.defaultParagraphStyle().mutableCopy() as! NSMutableParagraphStyle
style.alignment = .Justified
style.firstLineHeadIndent = 10.0
style.headIndent = 10.0
style.tailIndent = -10.0
let attrText: NSAttributedString = NSAttributedString(string: title, attributes: [NSParagraphStyleAttributeName:style])
let label: UILabel = UILabel(frame: someFrame)
label.numberOfLines = 0
label.attributedText = attrText

对于多行文本，可以使用NSAttributedString设置左右边距。

NSMutableParagraphStyle *style =  [[NSParagraphStyle defaultParagraphStyle] mutableCopy];
style.alignment = NSTextAlignmentJustified;
style.firstLineHeadIndent = 10.0f;
style.headIndent = 10.0f;
style.tailIndent = -10.0f;   

NSAttributedString *attrText = [[NSAttributedString alloc] initWithString:title attributes:@{ NSParagraphStyleAttributeName : style}];  

UILabel * label = [[UILabel alloc] initWithFrame:someFrame];
label.numberOfLines = 0;
label.attributedText = attrText;

以下是Swift 5采用的上述示例:

extension UILabel {
    func setMargins(margin: CGFloat = 10) {
        if let textString = self.text {
            var paragraphStyle = NSMutableParagraphStyle()
            paragraphStyle.firstLineHeadIndent = margin
            paragraphStyle.headIndent = margin
            paragraphStyle.tailIndent = -margin
            let attributedString = NSMutableAttributedString(string: textString)
            attributedString.addAttribute(.paragraphStyle, value: paragraphStyle, range: NSRange(location: 0, length: attributedString.length))
            attributedText = attributedString
        }
    }
}

在Swift中，它是这样解决的。

class Label: UILabel {
    override func drawTextInRect(rect: CGRect) {
        super.drawTextInRect(UIEdgeInsetsInsetRect(rect, UIEdgeInsets(top: 0, left: 10, bottom: 0, right: 10)))
    }
}

blyabtroi的asnwer在Swift中转换(不需要子类化)

let style: NSMutableParagraphStyle = NSParagraphStyle.defaultParagraphStyle().mutableCopy() as! NSMutableParagraphStyle
style.alignment = .Justified
style.firstLineHeadIndent = 10.0
style.headIndent = 10.0
style.tailIndent = -10.0
let attrText: NSAttributedString = NSAttributedString(string: title, attributes: [NSParagraphStyleAttributeName:style])
let label: UILabel = UILabel(frame: someFrame)
label.numberOfLines = 0
label.attributedText = attrText

Xcode 6.1.1 Swift扩展解决方案。

文件名可以是"UILabel+AddInsetMargin.swift":

import UIKit

extension UILabel
{
    public override func drawRect(rect: CGRect)
    {
        self.drawTextInRect(UIEdgeInsetsInsetRect(rect, UIEdgeInsets(top: 0, left: 5, bottom: 0, right: 5)))
    }
}

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