How can I make a background color with opacity on a Sheet view?

Question

I'm currently developing an application using SwiftUI.

I'm looking for some way to make a background color with opacity on a Sheet view.

is there any way to do that?

---

I've tried to do that with a code below, I can change the color with opacity property, but I can't see a text(Sheet) under the sheet View...

import SwiftUI

struct ContentView: View {
    
    @State var isSheet = false
    
    var body: some View {
       
        Button(action: {self.isSheet.toggle()}) {
            Text("Sheet")
        }.sheet(isPresented: $isSheet){
            Color.yellow.opacity(0.5)
        }
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}  

---

Xcode: Version 11.7

Swift: Swift 5

Answer 1

You cannot do it with standard sheet official API (because every hosting controller view by default is opaque), so you can either create custom sheet view (with any features you needed) or use run-time workaround to find that view and set its background to clear. Like below (only for demo)

struct DemoView: View {

    @State var isSheet = false

    var body: some View {

        Button(action: {self.isSheet.toggle()}) {
            Text("Sheet")
        }.sheet(isPresented: $isSheet){
            Color.yellow.opacity(0.5)
                .background(BackgroundClearView())
        }
    }
}

struct BackgroundClearView: UIViewRepresentable {
    func makeUIView(context: Context) -> UIView {
        let view = UIView()
        DispatchQueue.main.async {
            view.superview?.superview?.backgroundColor = .clear
        }
        return view
    }

    func updateUIView(_ uiView: UIView, context: Context) {}
}

Answer 2

Using the AWESOME answer from @Asperi that I have been trying to find all day, I have built a simple view modifier that can now be applied inside a .sheet or .fullScreenCover modal view and provides a transparent background. You can then set the frame modifier for the content as needed to fit the screen without the user having to know the modal is not custom sized.

import SwiftUI

struct ClearBackgroundView: UIViewRepresentable {
    func makeUIView(context: Context) -> some UIView {
        let view = UIView()
        DispatchQueue.main.async {
            view.superview?.superview?.backgroundColor = .clear
        }
        return view
    }
    func updateUIView(_ uiView: UIViewType, context: Context) {
    }
}

struct ClearBackgroundViewModifier: ViewModifier {
    
    func body(content: Content) -> some View {
        content
            .background(ClearBackgroundView())
    }
}

extension View {
    func clearModalBackground()->some View {
        self.modifier(ClearBackgroundViewModifier())
    }
}

Usage:

.sheet(isPresented: $isPresented) {
            ContentToDisplay()
            .frame(width: 300, height: 400)
            .clearModalBackground()
    }