SwiftUI 自定义UINavigationBar背景颜色

[josercc]

struct NavigationBarModifier: ViewModifier {
    var backgroundColor: UIColor?
    init( backgroundColor: UIColor?) {
        self.backgroundColor = backgroundColor
        let coloredAppearance = UINavigationBarAppearance()
        coloredAppearance.configureWithTransparentBackground()
        coloredAppearance.backgroundColor = .clear
        coloredAppearance.titleTextAttributes = [.foregroundColor: UIColor.white]
        coloredAppearance.largeTitleTextAttributes = [.foregroundColor: UIColor.white]

        UINavigationBar.appearance().standardAppearance = coloredAppearance
        UINavigationBar.appearance().compactAppearance = coloredAppearance
        UINavigationBar.appearance().scrollEdgeAppearance = coloredAppearance
        UINavigationBar.appearance().tintColor = .white

    }

    func body(content: Content) -> some View {
        ZStack{
            content
            VStack {
                GeometryReader { geometry in
                    Color(self.backgroundColor ?? .clear)
                        .frame(height: geometry.safeAreaInsets.top)
                        .edgesIgnoringSafeArea(.top)
                    Spacer()
                }
            }
        }
    }
}

extension View {
    public func navigationBarBackgroundColor(_ backgroundColor: UIColor?) -> some View {
        self.modifier(NavigationBarModifier(backgroundColor: backgroundColor))
    }
}