SwiftUI Text行高调整：_lineHeightMultiple弃用后报错求助

可行方案1：利用AttributedString结合自定义字体（iOS 15+） #

从iOS 15开始，AttributedString支持通过自定义字体的行高参数控制行高，可替代弃用的_lineHeightMultiple：

struct SmallLineHeightText: View {
    let text: String
    let lineHeightMultiple: CGFloat
    
    var body: some View {
        if let font = UIFont.systemFont(ofSize: 17).with(lineHeightMultiple: lineHeightMultiple) {
            Text(AttributedString(text, attributes: .init([.font: font])))
        } else {
            Text(text)
        }
    }
}

// UIFont扩展，生成指定行高倍数的字体
extension UIFont {
    func with(lineHeightMultiple: CGFloat) -> UIFont? {
        let descriptor = fontDescriptor.addingAttributes([
            .lineHeightMultiple: lineHeightMultiple
        ])
        return UIFont(descriptor: descriptor, size: pointSize)
    }
}

调用示例：

SmallLineHeightText(text: "Hello world!\nHello world!", lineHeightMultiple: 0.83)

可行方案2：自定义UIViewRepresentable封装UILabel（兼容iOS 13+） #

如果需要兼容iOS 13，可调整UILabel的布局逻辑确保和SwiftUI对齐：

struct CustomLineHeightLabel: UIViewRepresentable {
    let text: String
    let lineHeightMultiple: CGFloat
    let fontSize: CGFloat
    
    func makeUIView(context: Context) -> UILabel {
        let label = UILabel()
        label.numberOfLines = 0
        label.lineBreakMode = .byWordWrapping
        label.baselineAdjustment = .alignBaselines
        label.setContentCompressionResistancePriority(.defaultLow, for: .horizontal)
        return label
    }
    
    func updateUIView(_ uiView: UILabel, context: Context) {
        let paragraphStyle = NSMutableParagraphStyle()
        paragraphStyle.lineHeightMultiple = lineHeightMultiple
        let attributes: [NSAttributedString.Key: Any] = [
            .font: UIFont.systemFont(ofSize: fontSize),
            .paragraphStyle: paragraphStyle
        ]
        uiView.attributedText = NSAttributedString(string: text, attributes: attributes)
    }
}

调用示例：

CustomLineHeightLabel(text: "Hello world!\nHello world!", lineHeightMultiple: 0.83, fontSize: 17)
    .frame(maxWidth: .infinity, alignment: .leading)

若仍有布局偏移，可在SwiftUI侧添加alignmentGuide对齐基线：

.alignmentGuide(.firstTextBaseline) { $0[.bottom] }

方案说明 #

• 方案1是iOS 15+的原生解决方案，无需依赖UIKit，布局贴合SwiftUI原生行为。
• 方案2兼容iOS 13+，通过调整UILabel属性和SwiftUI布局参数，可解决之前的布局不符问题。

内容的提问来源于stack exchange，提问作者Nikita Tepliakov