UITextView 和 NSAttributedString 未在 SwiftUI 中显示

Question

我正在尝试通过 UIViewRepresentable 使用 UITextView 和 NSAttributedString。这是我的代码。

AttrText 是包含文本 (String) 以及有关文本颜色和字体的信息的结构。

struct TextView: View {
  let attrTextList: [AttrText]
  let size: CGFloat
  let lineSpacing: CGFloat

  var body: some View {
    IntegratedTextView(attrTextList: attrTextList, alignment: .left, size: size)
        .frame(minWidth: 0, maxWidth: .infinity)
  }
}

struct IntegratedTextView: UIViewRepresentable {
  let attrTextList: [AttrText]
  let alignment: NSTextAlignment
  let size: CGFloat

  init(attrTextList: [AttrText], alignment: NSTextAlignment, size: CGFloat) {
    self.attrTextList = attrTextList
    self.alignment = alignment
    self.size = size
  }

  func makeUIView(context: Context) -> UITextView {
    let textView = UITextView()

    let result = attrTextList.map { text -> NSAttributedString in
          var attrString = NSMutableAttributedString(string: text.text)
          let attribute: [NSAttributedString.Key: Any] = [
            NSAttributedString.Key.font: processFont(text: text, size: size),
            NSAttributedString.Key.foregroundColor: processColor(text: text)
          ]
          attrString.addAttributes(attribute, range: NSRange(location: 0, length: attrString.length))
          return attrString
        }
        .reduce(NSAttributedString(string: ""), +)

    textView.attributedText = result
    textView.textAlignment = alignment

    print("TextView: \(textView)")
    return textView
  }

  func updateUIView(_ textView: UITextView, context: Context) {
  }

  func processColor(text: AttrText) -> UIColor {
    //something return color by AttrText
  }

  func processFont(text: AttrText, size: CGFloat) -> UIFont {
    //something return font by AttrText and size
  }

}

extension NSAttributedString {
  static func +(left: NSAttributedString, right: NSAttributedString) -> NSAttributedString {
    let result = NSMutableAttributedString()
    result.append(left)
    result.append(right)
    return result
  }
}

我认为它应该有效，但事实并非如此。当我打开应用程序时，IntegratedTextView 是不可见的。通过 print("TextView: \(textView)")，我检查了控制台日志，它打印如下。

TextView: <UITextView: 0x1351c3600; frame = (0 0; 0 0); text = 'It's Text'; clipsToBounds = YES; gestureRecognizers = <NSArray: 0x280682700>; layer = <CALayer: 0x2808e5700>; contentOffset: {0, 0}; contentSize: {0, 40}; adjustedContentInset: {0, 0, 0, 0}>

有没有人如何解决这个问题？

Answer 1

这个问题是由ScrollView调用的。

我的 TextView() 在较高视图中被 ScrollView 包裹。

您可以在 link ->

中找到答案

UITextView 和 NSAttributedString 未在 SwiftUI 中显示

UITextView and NSAttributedString is not showing in SwiftUI

ios

swift

uitextview

nsattributedstring