针对动态字体准备好你的 Apple tvOS App

4:58 - Adopt standard text styles

// Adopt standard text styles

VStack(spacing: 20) {
  Text("Signup information")
    .font(.caption.bold())
    .lineLimit(1)
    .foregroundStyle(.secondary)
    .frame(width: 300, alignment: .leading)
  HStack(alignment: .top, spacing: 40) { 
      //* ... *//
  }
}

5:10 - Use flexible constraints

// Adopt standard text styles

VStack(spacing: 20) {
  Text("Signup information")
    .font(.caption.bold())
    .lineLimit(1)
    .foregroundStyle(.secondary)
    .frame(maxWidth: .infinity, alignment: .leading)
  HStack(alignment: .top, spacing: 40) { 
      /* ... */
  }
}

5:55 - Dynamic Type with text styles in UIKit

// Hard coded text size in UIKit

titleLabel.font = UIFont.boldSystemFont(ofSize: 28)

// Dynamic Type with text styles in UIKit

titleLabel.font = UIFont.preferredFont(forTextStyle: .headline)
titleLabel.adjustsFontForContentSizeCategory = true

7:09 - Adapt layout in response to dynamic type

// A view that shows a collection of movie posters

struct MovieShelf: View {
  @Environment(\.dynamicTypeSize) private var dynamicTypeSize
  var body: some View {
    ScrollView(.horizontal) {
      LazyHStack(spacing: 40) {
        ForEach(Asset.allCases) { asset in
          Button { 
            /* ... */
          } label: {
            asset.portraitImage
            Text(asset.title)
          }
          .containerRelativeFrame(
            .horizontal,
            count: dynamicTypeSize.isAccessibilitySize ? 4 : 6,
            spacing: 40)
        }
      }
    }
  }
}

8:07 - Provide a conditional layout for when larger sizes are turned on

// A view that shows content in a card

struct CardContentView: View {
  @Environment(\.dynamicTypeSize) private var dynamicTypeSize
  var asset: Asset

  var body: some View {
    let layout = dynamicTypeSize.isAccessibilitySize ?
      AnyLayout(VStackLayout(alignment: .leading, spacing: 10)) :
      AnyLayout(HStackLayout(alignment: .top, spacing: 10))
    layout {
      /* ... */
    }
  }
}

8:31 - UIKit adaptive layout that responds to content size changes

// UIKit adaptive layout that responds to content size changes

class AdaptiveLayoutViewController: UIViewController {
  let stackView = UIStackView()
  
  override func viewDidLoad() {
    super.viewDidLoad()
    updateLayout()

    let sizeTraits: [UITrait] = [UITraitPreferredContentSizeCategory.self]
    registerForTraitChanges(sizeTraits, action: #selector(updateLayout))
  }

  private func updateLayout() {
    if traitCollection.preferredContentSizeCategory.isAccessibilityCategory {
      stackView.axis = .vertical
    } else {
      stackView.axis = .horizontal
    }
  }

}