在 SwiftUI 中的视图之间传递数据？

Question

I'm trying to pass a few simple data (strings and URL and images) from one view to another view in my swiftui app.

This simple task proves to be a headache at the moment.

This is what I have done so far:

in my firstView I have this:

struct Book {
    var title: String
    var author: String
}

struct firstView: View {

    @State private var showAudioPlayer = false

    @Binding var tabSelection: Int

    init(tabSelection: Binding<Int>) {        
    
        _tabSelection = tabSelection    
    }    

    var body: some View {

       NavigationView {
          ZStack {

             Text("Tap Here")
             .onTapGesture {
                 self.showAudioPlayer.toggle()
             }        
          }        
      }
      .fullScreenCover(isPresented: $showAudioPlayer, content: secondView.init)

    }

}

And this is what I have in my secondView :

struct secondView: View {

    @Environment(\.presentationMode) var presentationMode

    var book: Book
    
    var body: some View {
                
        NavigationView {
            
                      ZStack{
                        
                          VStack {                                
                        
                          }
                      }
                    
                      .background(Color.clear)
             
                      .navigationBarTitle("", displayMode: .inline)    
                    
                    .navigationBarItems(
                          leading: Button(action: {
                          
                            presentationMode.wrappedValue.dismiss()
                            
                            
                        }) {
                            Image(systemName: "chevron.down.circle")
                                .foregroundColor(Color.black)                                    
                            
                        })
                      .frame(maxWidth: .infinity, maxHeight: .infinity)
                       .edgesIgnoringSafeArea(.all)
                            
                  }

        .edgesIgnoringSafeArea(.all)
    }

}

However, when I try to compile my code, I get this error:

The error itself doesn't make much sense and I'm stuck.

what am I doing wrong?

Answer 1

Memberwise Initializers for Structure Types

The compiler takes a peak into the struct and sees two non-optional properties and thinks they should be in the constructor. It doesn't know the @Environment is going to magically be set by the framework, so it includes that property. As @Baglan said above, you are on the hook for the Book and need to pass it in.

The error message is saying "you asked me to instance audioPlayerView and I need a couple of parameters to make that happen", but you really only need one.