swift - 如何在没有固定宽度的情况下让文本包裹在 UILabel(通过 UIViewRepresentable)中？

Question

将 lineBreakMode 设置为 byWordWrapping 并将 numberOfLines 设置为 0 似乎还不够:

struct MyTextView: UIViewRepresentable {
    func makeUIView(context: Context) -> UILabel {
        let label = UILabel()
        label.lineBreakMode = .byWordWrapping
        label.numberOfLines = 0
        label.text = "Here's a lot of text for you to display. It won't fit on the screen."
        return label
    }

    func updateUIView(_ view: UILabel, context: Context) {
    }
}

struct MyTextView_Previews: PreviewProvider {
    static var previews: some View {
        MyTextView()
            .previewLayout(.fixed(width: 300, height: 200))
    }
}

无论我对 lineBreakMode 使用哪种设置，文本都不会换行。 Canvas 预览和实时预览都如下所示:



我得到的最接近的是设置 preferredMaxLayoutWidth，这确实会导致文本换行，但似乎没有一个值表示“无论 View 大小如何”。

Answer 1

可能的解决方案是将宽度声明为 MyTextView 上的变量:

struct MyTextView: UIViewRepresentable {

    var width: CGFloat

    func makeUIView(context: Context) -> UILabel {
        let label = UILabel()
        label.lineBreakMode = .byWordWrapping
        label.numberOfLines = 0
        label.preferredMaxLayoutWidth = width
        label.text = "Here's a lot of text for you to display. It won't fit on the screen."
        return label
    }

    func updateUIView(_ view: UILabel, context: Context) {
    }
}

然后使用 GeometryReader 找出有多少可用空间并将其传递给初始化器:

struct ExampleView: View {

    var body: some View {
        GeometryReader { geometry in
            MyTextView(width: geometry.size.width)
        }
    }
}