通过UIVisualEffectView可以实行毛玻璃效果。

struct VisualEffectView: UIViewRepresentable {
    var effect: UIVisualEffect?
    func makeUIView(context: UIViewRepresentableContext<Self>) -> UIVisualEffectView { UIVisualEffectView() }
    func updateUIView(_ uiView: UIVisualEffectView, context: UIViewRepresentableContext<Self>) { uiView.effect = effect
        uiView.alpha = 0.6
    }
}

struct ContentView: View {

    var body: some View {
        ZStack {
            Image("BG")
                .resizable()
                .scaledToFill()
                .edgesIgnoringSafeArea(.all)
            
            VisualEffectView(effect: UIBlurEffect(style: .dark))
                .edgesIgnoringSafeArea(.all)
                
            Text("Hello \nVisual Effect View")
                .font(.largeTitle)
                .fontWeight(.black)
                .foregroundColor(.white)
        }
    }
}