效果

实现方式

为了方便使用，采用ViewModifier的方式

一、创建ViewModeifier

struct Loading: ViewModifier {
  static let showNotification = Notification.Name("Loading.showNotification")
  static let hidenNotification = Notification.Name("Loading.hidenNotification")
  @State private var isContentShowing = false
  @State private var isPresented = false
 
  var touchable = false
  func body(content: Content) -> some View {
    ZStack {
      content
      if isPresented {
        ProgressView()
          .tint(Color.white)
          .padding(20)
          .background(Color.black.opacity(0.7))
          .cornerRadius(8)
      }
    }.onAppear(perform: {
      isContentShowing = true
    }).onDisappear(perform: {
      isContentShowing = false
    }).onReceive(NotificationCenter.default.publisher(for: Loading.showNotification)) { output in
      guard isContentShowing else {
        return
      }
      isPresented = true
    }.onReceive(NotificationCenter.default.publisher(for: Loading.hidenNotification)) { output in
      guard isContentShowing else {
        return
      }
      isPresented = false
    }
  }
  
  static func show() {
    NotificationCenter.default.post(name: Loading.showNotification, object: nil)
  }

  static func hidden() {
    NotificationCenter.default.post(name: Loading.hidenNotification, object: nil)
  }
}

二、扩展View

extension View {
  func loadingable() -> some View {
    return self.modifier(Loading())
  }
}

使用

 var body: some View {
    VStack {
      Spacer()
      Button("展示") {
        Loading.show()
      }
      Spacer()
      Button("隐藏") {
        Loading.hidden()
      }
      Spacer()
    }.loadingable()
  }